Anyone fluent with Tankless Water Heaters? Plumber, perhaps?

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BobKones

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Jan 3, 2023
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Location
Outer Mongolia
Hi folks!

I have a class A that I've been living in for around 5 years. When I started out the first thing I noticed was the cheesy showers so I fixed that a couple of years ago. I have an Atwood 10 gallon tank and I turned it into a boiler that runs at 180f for increased capacity. The hot feed from the tank goes through a commercial grade mixing valve that regulates it to 118f to the rest of the unit. This is my ideal shower temperature.

What this does for me is get me about a 25 minute shower at the exact same temperature from start to finish. Any longer and you get gradual temp drop but generally I'm in for 20 minutes at the most. Any longer and I deserve what I get :) I revised the control system for the tank so that I can control the desired temperature/offset independently for gas and electric (idea being that both come on very quickly to fight the temperature drop as you shower). It's paid big dividends. I've never had to look at it since the original design...

..up until the last week or so! The 23 year old Atwood tank now looks like it's leaking, and probably weeping from a tiny hole in the bottom somewhere. It doesn't look like it's any of the fittings :(

I typically remove the tank annually for scale removal/flushing and it's pretty ratty inside. It would not surprise me if it's got thin spots from erosion all over. In other words, it likely needs to be replaced. I cannot get a replacement tank anymore (too old) so I have to get a whole new water heater.

This brings me to wonder if I should consider going tankless. The hydro usage on my tank right now is monitored in real time and it costs me about $20 a month to run it. I'm on a bit of a hydro kick lately and have cut it back considerably with a residential fridge. I wouldn't mind recouping that $20 as well and see just how low I can get it.

I'm looking at a 2.9 GPM Fogatti (55,000 BTU). Standing water pressure is 100 PSI and operating pressure is typically ~60 PSI. That max on the Fogatti is 116 and the new pump I have coming flows 5.3 GPM. So...by the looks of it the pump should outperform the unit. (I also have a 2 gallon accumulator installed).

Research shows that the Girard units suffer from thin copper in the heat exchangers where they bend the pipes and that they tend to pack it in due to the paper thin copper in these areas. Also, their unit is less BTU's. This is what brought me to the Fogatti.

My biggest question is, given the effort I've gone through to maintain a perfect temp shower from start to finish, do you think a tankless unit is up to the task or would it end in disappointment? Ambient temps in winter can be as low as -7c (19.4f) and I use a heating cable on the fresh water feed for a few weeks (typically) per year. Incoming water temp should be about 2c / 35.6f

Reading the reviews is not always ideal because everyone is ecstatic over 'endless' hot water, even though both of those units apparently shut off after 20 minutes...which few people mention. Also, there are virtually no reviews stating actual water temperature consistency over the duration of a shower or what the actual temperatures are. This is subjective, of course. For one person, 'endless' hot water could just mean it's not cold and it lasts much longer. I prefer to generate steam when I shower, but what I really like is that right now, I just put the hot on full and it runs start to finish at the temperature I preset on the mixing valve. And it's very, very accurate because all it's doing is slowly emptying a tank that starts out at 180f and the mixing valve does the rest.

What do you think my chances of success are if I moved over to a tankless water heater?
Lastly, do these units generate a lot of scale that ends up in the aerators?
Much thanks to anyone that has actual experience with these things!
 
I put a Eccotemp L5 in my daughter's old truck camper. It's hanging on the wall inside the all-in-one bathroom. Gives very hot showers. We don't do the "shut-off" while showering otherwise it results in very cold water for a few seconds which is horrible. It's winterized for now. The last cold month it was used was early Nov and nighttime temps were just getting to freezing. It still did a very hot shower using the fresh water tank.
 
Look carefully at the flow rate vs. temperature rise for any tankless heater you're considering. It takes 1 BTU to raise the temperature of 1 lb of water by 1 degree F and the water isn't exposed very long to the heat source as it flows through the heater.

You may have to decide between a good flow rate or high temperature water when the weather gets cold
 
+1 on Lou's post. It's a simple formula of BTU in, temp in to temp out vs flow. Most tankless I've seen start with 60F water supply and those barely give you a 60F rise from there at modest flow. The larger tankless take a terrific amount of gas CFM to operate, which translates to a high flow regulator and piping to supply it adequately. Something a plumber I know mentioned is the water in most municipal systems will require a pre-filter, or the exchanger will get fouled with sediment and scale. Not a deal breaker per se but both the filter and exchanger need periodic attention just as a tank does. A friend of mine has a large home with two tankless heaters and he ended up refitting them with recirculation pumps and timers because of the lag in heated water. So during the day the things periodically cycle to keep the water in the pipes hot which in my mind isn't much different (and likely less efficient) than keeping hot water in a tank. When I factored all the pro's and con's of tank vs tankless I ended up installing a basic tank in my home when I did a remodel. I just couldn't see an upside to tankless, when a tank has been more than adequate in the near 25 years I've been in this home. Same can be said for my RV - the 6 gallon job in there has more than enough capacity to do anything I would need with a 60 gallon fresh tank, so why complicate it for no net benefit. Even when I had hair I never spent more than 10 minutes in a shower. Seems you could transfer your thermal controls/mixer to any other water heater, that'd be my plan.

Mark B.
Albuquerque, NM
 
Thank you guys, especially Mark, I think you may have given me the answer I was looking for although I wanted the tankless to work....not quite there yet but getting closer to driving a nail in the tankless coffin!

More research shows the Fogatti is a Chinese outfit. Not acting as a manufacturing agent for a Western company, but a direct from China company. So there's that...

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According to that map I'm in the lowest ground water temperature zone, at least in winter.
Since the unit would be running off my fresh water tank, the typical temp of the intake water in winter would be 8c or 46.4f

So that would get me into the 47f / 1.6 GPM zone with the 55,000 BTU unit. This should be the worst case winter scenario.

I guess I'm going to have to measure exactly how much water comes out of my shower head in one minute to see how that flow rate compares to what I have now to remove some fog from the equation.

1.6 gallons per minute = 13.36 lbs. Not sure (even if it's simple math) how to determine what the outlet temperature should be under those circumstances with a 55,000 BTU unit. If you could show the math for me, I'd appreciate it! My brain is a bit fried already just from the research as this leak showed up just yesterday...

Mark, all your points sound valid to me. I was already thinking that the proper way to really nail it would be to install a residential type unit and plumb an exhaust port. Preliminary research shows half inch gas fittings which indicates to me, if you really want that hot water, you need more gas flow, ie, more BTU's to bring you into the area of using the mixing valve to cut the temperature back which is a nice place to be and where I am now with the 180f boiler conversion.

My issue is that I need to do something very soon because it's weeping now. I cannot get a replacement tank as it's no longer available. I could buy a new tank and move the gear over, it's not the end of the world, but...if I have to do that I would prefer to remove the tankless from the equation entirely. What is stopping me from that are two things, knowing my current flow at the shower per minute, and estimating the outlet water temp given the information above.

If anyone can help with the math on that, I would really appreciate it. Hopefully there is enough infor there to determine, roughly, the temps I would be seeing?

I'm also thinking of taking the tank out and having a large patch welded on it. Pretty sure, if that's doable, it would also address the issue and kick it down the road. On the other hand, it's now 23 years old :)

Either way, everyone's help is much appreciated! I need to make a decision soon as I'm sure the weep will turn into a leak and then into a wet bedroom carpet if I procrastinate on it. All this, while I'm also fixing my car and preparing for a new water pump for the wet bay to arrive. When it rains, it pours. Or maybe I shouldn't say that....
 
It comes down to flow rate and temp rise. There's a range within that too, you don't get a 200,000BTU heater to fill up a coffee machine, there's a limit to how much "dynamic range" these things have to maintain a constant output temperature. So you kinda want to match the rise and flow as close as you can. (Contrast that to a tank, where you get nearly constant temp for most of the tank capacity at any flow).

Totally at random here's a spec for one off the google:

Flow Rate @ 35°F Rise (gallons/min)7.5 gal (US)/min
Flow Rate @ 45°F Rise (gallons/min)6.7 gal (US)/minFlow Rate @ 55°F Rise (gallons/min)5.3 gal (US)/min
Flow Rate @ 65°F Rise (gallons/min)4.5 gal (US)/min

So you take your inlet temperature and match it up to the rise you want at the flow you have. For a 1.5 GPM shower and say 60-70F input temp then some electrics would probably keep up. For greater rise and flow you're pretty much bound to propane or natural gas.

About the only benefit I see to tankless is if you really need huge volumes of heated water, say a large family taking a dozen showers a day or a business that uses a lot. Even with hookups I've never seen a need to stand in my RV shower/phone booth for longer than necessary. I tested it once, could go a solid 20 minutes before the water ran cold with one of those oxygenics shower heads, so for me that's about a 50% margin. I get your predicament with the obsolete tank though. Maybe go with an inexpensive residential tank heater plumbed in until you can/decide to refit another RV one.

Mark B.
Albuquerque, NM
 
BTU ratings for gas appliances are in BTUs per hour and we know it takes 1 BTU to raise the temperature of 1 lb of water by 1 degree F.

So, if we know that the Fogatti produces 55,000 BTU per hour of heat we can work backward to find the maximum flow rate vs. temperature rise.

If you want to raise the temperature by 60 degrees F you can heat (55,000 / 60) = 916 lbs of water per hour.

Water weighs 8.5 lbs per gallon, so 916 lbs = 108 gallons per hour, or (108/60) = 1.8 gallons per minute.

For a 40F temperature rise, it's (55,000 / 40) = 1375 pounds of water, 161 gallons per hour or 2.7 gallons per minute.

In actuality the flows will be a bit lower than these because the flame doesn't transfer 100% of it's heat energy to the water. Some, maybe 20-40% escapes out the exhaust which reduces the maximum flow rates by a like amount.
 
I would suggest that, if you have the room for it, you just buy an electric 10 gallon tank "point of use" water heater. Otherwise buy a new 6 or 10 gallon RV tank water heater. Running off a Shurflo 2088 water pump, an Oxygenics handheld RV shower head and a 10 gallon tank electric point of use water heater set at the highest setting, I can take a 25 minute very hot shower before the water starts cooling off. And I don't turn the water off until I am ready to get out of the shower. In that time I can wash my hair or shave my legs plus wash my self. And that's not a fast shower. I used to run a 60 gallon tank water heater empty when I was showering in a house. I usually take a 15 to 20 minute shower. It's all in what you get used to.

My Class C had a 6 gallon RV water heater (LP/AC but we only ran it on AC). With a low flow shower head, I still took 15 minute hot showers. I think you have been dealing with an old inefficient water heater for a long time.
 
Hi guys!

My apologies for the delay in replying. This morning the idea came to me to perhaps see if I could get the tank welded. So I called up a welder and I explained I'd like a large patch put on it to cover the bottom where the scale has rotted the tank. He figured it would be no problem, he's seen them before, likely $150 and...he had some time...

So I ripped the tank out this afternoon and ran it up there. He wanted to pressure test it first so I left it with him. He called back by the end of the day and said he'd ran it right up to 60 psi and...no leaks. So I drove back to pick it up but on the way I was thinking about it.....

The conclusion I came down to was that it's probably not leaking unless it's hot and the aluminum expands. His suggestion was to either have it hydrostatically tested or to install it again, this time sans the styrofoam packaging so that I could see where it leaks and then bring it back.

$40 later I was on my way back. So I installed it tonight without the styrofoam. I then filled and purged the system and put the pump on to bring it up to ~70 PSI. No leaks. Nothing. I then turned the gas and electric on (2,000 watts) and ran it up to 180. Then I could see that the entire left side of the tank, not the bottom, but 1/4 way up, had very tiny leaks along the entire side. Basically just the odd bubble of water slowly dripping out and down. So it appears the entire left side of the tank wall is weak. But...as I suspected, it will only show up under full temp and pressure.

The welder wanted $200 to patch it, but he didn't really want to do it the way I wanted, which was more/less put a large patch all around the bottom and up the sides. Thing is, I know how ratty the bottom is, so for $200 I really wanted to see the entire thing reinforced. To me, it's simple.

But when I saw it with the cover off I realized it's not just one spot, it's different spots of the entire side wall. Dad never flushed the tank. So from new (2000) to about 2017 that tank was never flushed. And the corrosion inside shows it. Then I turned it into a boiler and ran it at pressure, which, to be sure, was asking a lot from it. I guess I should have bought a new tank when I first saw what it looked like inside and they were still available...

So...that brings me back to...either replace the entire hot water heater with a new one or...back to tankless. I read the reviews again on the Girard and it seems many people have had them for 6 years or more. The new design is apparently much better than the first revision. Also, several people were quoting 50f inlet temps and great hot water. Further, one user was getting hot water out of his at -40c after insulating his tank and his lines. Turns out at -40c propane doesn't really like to flow anymore...The worst I see in my area is -7c and that is for a very short period of time, 2 weeks tops.

Because I had the tank out and fully emptied I got to see the exact temp of the tank with fresh cold water. The water temp was 58.2f That actually puts me very close to what should be a desired outlet temp of 118f. Bearing in mind, this is early January.

So, either a new tank (same old same old) or a new tankless. I pulled the trigger on the Girard a few minutes ago. It's actually about $200 less than my buying a new tank and that includes the conversion door. I checked the prices on parts for it in the event it packs it in post-warranty and the heat exchanger was around $250....to me, parts availability and price take a lot of the risk out of it.

It appears that water volume and pressure are important to tankless heaters. I have full control over that since it's going to run predominantly off the pump. I have a new 5.3 gallon pump coming shortly and I ordered up a separate pressure control switch for it from the HVAC/boiler industry so I can have full granular and reliable control of the cut out and the offset (I got tired of the cheesy microswitches in pumps and also run a separate brass full flow check valve). This way as long as the pump motor works and the head gasket has integrity, I'm good to go.

But at the end of the day, having pulled and re-installed the tank, I said to myself, I really don't want to be doing that on a regular basis. And I have been pulling the tank annually to properly flush out the tons of scale buildup I get. It's embedded into the sides of the tank. I get TONS of scale, huge nuggets the size of peanuts. The only way you could get all the scale out of the sides of the tank would be to chemically strip it but I'm quite sure the scale is providing structural integrity to the tank at this point!

Anyway, I ordered up a Girard 2GWHAM off Amazon. That way, if it turns out to be a lemon, or just can't cut it, it can go right back for full refund. But from the ambient inlet water temps I saw in the reviews, many much colder than mine, it sounds viable.

Many thanks to everyone for your help on this. I knew in my gut that the Girard was preferable over the Chinese Fogatti, when I saw the parts availability and pricing that took a lot of the risk out of it for me and shifted me from going tank again to trying tankless.

It's supposed to be here in 5 days, if you like I can post back my findings as you can be sure I will be measuring all the outlet temps to see what the real deal is. So I have more plumbing to do. First the new Remco Rebel Pump, then the separate pressure switch, then the Girard. Oh, and I also have a new City/Water valve coming (3-way L Port). That is a bear to install. I'm on my third now, this time I bought one direct from Swan Industries in the hopes that it's a good one. After 20 years the original packed it in and started leaking into the fresh tank overfilling it. I then re-tasked the same valve that was used in the water tank bypass (since it was never really used I assumed it had to be like new)...only to find it also leaked. The third was a new one sourced off Amazon and looked great. But...sure enough...it's leaking too. I believe the ones from Swan Industries are actually sourced from Japan...

I went from having perfect water for years to having nothing but water problems in the span of about a week. Ughh...here's hoping a marathon plumbing session nails it all for many more years!
 
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I have a small tankless water heater and like it. It requires 2 - 40 amp circuits to power it. Do you have a electrical service to handle that load?
 
Tankless heaters do not like limescale. You will need to condition the water or use a water softener.
 
Neither does my Atwood tank :)

Before I reinstalled it last night I upended it and flushed it repeatedly. I seem to have to do this every 6 months. A wand will NOT clean it out. It's common to see scale as large as a quarter...

Interesting fact. Prior to pulling the tank and removing the scale (as much as can be done, a lot of it is embedded in the walls of the tank) my water pumps were overheating. In the winter. Typical operation is that I *might* see them overheat, perhaps once, in the mid summer. No less than 3 pumps have overheated recently. I changed out the 30 amp relay that powers them, no difference. In addition, the shower water has been very hard lately. I have 2 EM field generators on the water feed to help prevent scale formation.

So get this...I shower this morning off my old tank that I cleaned out yesterday and what do I notice? Much more water flow and WAY softer water. My skin is so soft it's crazy. I go out after the shower and touch the pump - luke warm.

I suspect that the scale was causing increased head pressure for the pump causing it to work much harder and overheat. I haven't had a soft shower like that for some time. The warmth is incredible. Also, the temperature was several degrees warmer. I had to turn the mixing valve to full hot a while back. Now I know why.

So just having scale buildup in the tank certainly does cause the water to be harder. There is no question. It's night & day.

I hear you the scale issue with the tankless system, but the sad fact is I'm combatting it now with the tank and have been for years. Literally every 6 months the tank needs to be pulled to descale. Certainly, running the tank as a boiler at 180f exacerbates the issue. Whether the tankless will be better or worse remains to be seen.

Here's some pics of the scale after they have been in the rain overnight dissolving. Ie, they are much smaller now then when they came out of the tank!
 

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Well, I took the plunge and got the Girard 2GWHAM aka GSWH-2 and installed it.
I ordered the conversion door for it but it turns out my Atwood had a 'flush mount' door which adds a ton of complexity and I could not come up with a way to solve the issue so I returned the door and removed the existing bezel from the tank and fabbed up an aluminum plate for the cover. I'll have it powder coated white on Monday.

It actually works very well. It took a bit of getting used to. My kitchen sink flows a TON of water (basically unrestricted) so I installed a spray nozzle on the end to reduce the volume. This helped a great deal. My shower head was already a low flow/high pressure unit and it worked very well. Bathroom sink is also not an issue.

So...with 46f inlet water temperature, and the unit set to 124f, I could easily get to scalding temps in the shower with decent flow. Flow being effectively identical to what I had with the tank. The difference is that on max flow (hot tap wide open) the temps drops a bit to just a good warm shower.

It takes a few minutes to get used to it. Normally, if you want more heat in the shower you open the hot valve more. In this case, the longer the water remains in the heater, the hotter it gets. So if you want more heat you close the valve a bit. If you want less heat, you open the hot valve.

Get it? You have to understand that what you are doing is keeping the water in the exchanger longer (more heat) or shorter (less heat).

There is a delay when you change the temperature in the shower. For instance, if it's scalding hot, and you open the hot tap more, to decrease the temperature of the water, it will take a little bit for that reduction to be reflected at the shower head. Or, you could just open the cold valve for faster results.

The flip side is, you can also just set the temperature on the panel to your perfect temp and leave it at that....the unit does keep accurate temps as compared to the setting if you allow enough time for the water temperature to stabilize from the unit, through the lines, to the fawcett.

But here's the thing, at 46f inlet temp (my winter water temp) I can easily get it hot enough to scald me with decent pressure. That, in my book, is a big success as this should be the toughest inlet temperatures it has to deal with. As winter comes to a close the performance should increase as the inlet water temperature increases. Since there are no temperature issues now, what that should mean is just increased flow.

Where it really shines is in the softness of the water. This is readily noticeable. The tank had so much scale imbedded in it that the water was more/less permanently hard unless it was just flushed and that did not last long. Scale is more/less non-existent in the heat exchanger at this point and you can really tell by the softness of the water. Skin and hair are much softer. Also, you can now drink or cook with hot water because there is no brown/black swamp water sitting in the bottom of the tank. That will never occur with a heater based on a heat exchanger because the water has nowhere to sit. The unit is always seeing fresh new water.

The one area where it's not as good as a tank (in the winter) is filling the sink to do dishes. I have to turn the flow down to get very hot water and then let it fill the sink which does take a bit longer. That I can live with because I can also get the sink water a lot hotter than before. I'd guess it takes twice as long to fill the sink. But...it is fully hot water. With the tank the sink would start to fill hot and as filled the temperature would drop due to the volume of water used. That is no longer the case. So there is a benefit there too.

Overall, I'm very impressed with it. One thing I wish people would do is refrain from reviewing it until they have used it for a few days. My initial thoughts were that it was too small and I was disappointed. This was because I opened the hot tap on full and stuck a thermometer under it. That amount of flow was way too much for it to handle and the temps reflected that.

The solution is to work with the system and not against it. And I wanted it to work. Putting a spray nozzle in the kitchen sink helped a great deal because it cut the ridiculous flow rate down. Turns out, my shower head was already perfect for the unit. Bathroom sink is no big deal - no issues there.

With respect to laundry, my washing machine is very modern and does not fill the washer immediately. It tumbles for a bit, then adds water, then tumbles, then adds more. This turns the unit off and on. So during filling it's best to leave the bathroom sink running a bit so that the washer gets fully hot water. On the flip side though, my washer does have it's own heater so if the water is not hot enough it will heat it. So that is mitigated.

Where I think the real benefit will be is in flushing the unit. In my case, the scale is so bad that you have to remove the tank and upend it to flush it. This means removing all the connections and pulling the heating element. That's a lot of work and you usually get wet. Then you have to reseal the wall/bezel and chase down any leaks you introduced in the process. In other words, it's a full afternoon and you never get all the scale out.

With this unit, I used clear braided hose with hand-tight fittings on the cold inlet and hot outlet. In this way I can easily flush the unit, from inside, and set it up in about 5 minutes. You just put a bucket in the compartment with a pump in the bottom, connect the two hoses to the unit, add some citric acid and let the pump run for a few hours. For me, that is a massive benefit. Opening the low point drains in the wet bay does clear the existing water from the lines, so no leaks when removing the lines.

The unit is much quieter than the tank. A nice small woosh when it comes on and effectively no noise when it's running. The freeze protection feature works. It comes on a bit early and works. When the temp gets to about 5c it comes on briefly, heats the exchanger, then shuts off and repeats as necessary.

Wiring it into the existing KIB panel above the sink was child's play. I reused the existing connector at the tank to make removal easier should it need to be done. Unplug the connector, the two connectors to the control, the two water lines and the propane line and it pops right out. This should not be necessary because you can flush the unit from the inside negating the need to remove it unless repairs are needed. The unit is much smaller than the tank and weighs almost nothing, about 20 pounds.

If repairs are needed, I can easily put it on my desk inside and fix it. Service manual was found on the Internet and turns out, it's a pretty simple system.

The most work was in fabbing up the door/panel cover. This is only required when you have a 'flush mount' door. They have replacement drop in doors for Atwood and Suburban heaters as long as the existing doors are not 'flush mount'.

I'm in possibly the worst place for this heater to operate due to the lower ambient and water inlet temperatures. Yet, it's fine. Shower temps (my primary concern) are hotter than before with same flow rate. When I think of the target market in North America, it's clear to me that it would work much better (read higher flow rates at higher temps) geographically almost everywhere else.

It's worth noting that most problems people encounter are where the inlet water temps are too high. Ie, Florida. If your water feed line is sitting in the sun this can cause problems. In a case like that you would want to increase the flow rate to maximum and protect the lines from the heat of the sun.

I do get periodic E3 errors (overheating) and this is due to my running it at the max temperature (124f). At some points when it shuts off it 'overheats', at least, it thinks it is when a certain set of circumstances take place. But this is a soft error and if you wait a few moments for it to cool off it resumes normal operation. I will solve this by changing out the 140f snap disk for a 160f. This should prevent the E3 from coming back but it's a very minor point.

It's also worth noting that typically, in an RV, you want that $350 Remco Pump that flows 5.3 gallons per minute and a nice high pressure. This works against the unit because the flow is too high, at least with my colder water inlet temperatures. As such, in my case, the typical $100 pump that does 3.2 GPM is even too big.....

So there is some thought required. If you were in Florida, for instance, you would probably want that $350 Remco pump to push as much water through as possible. In a hot climate you would have the opposite problem I had. You would have too much heat and could use much more volume.

But now I no longer turn off the hot water tank nor wait for it to heat up. Hot water is always 'on tap'. As far as delay time in getting hot water to the sink/tap - it's irrelevant. In my case, whether tank or tankless, there is always a delay because the cold water in the pipes has to be purged. You also have some control over the delay. If you turn the water on just enough for the unit to come on, you'll get hot water faster.

I am using more water, but since I'm getting it off a pedestal that's OK. Boondocking would require different considerations. Bottom line, otherwise easy install, excellent water temperature and flow in the shower (scalding if you want it) with 45f inlet temperature, very quiet and smooth, cheaper than a tank replacement (by far in my case), flushing is 10,000x easier, and no more turning the tank on and off. Oh, and also, endless hot water and no hydro bill ($20 per month savings as measured in real-time). It would not surprise me if the propane costs were cheaper too. After all, the unit only uses propane when you are using hot water.

But it is different. You have to think a little differently. And I do think, you have to want it to work. Here's some pics
 

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For locales where the incoming water may be too warm to kick the tankless burner on, you make sure you get a tankless water heater with a "solar option". This is for the people who heat their water with a solar batch heater or someone who lives someplace where the water gets heated due to the sun on the water pipe or the ground gets very hot ( like a feckin' desert in triple digit summer temps). Of course you can do what I do - insulate your water hose year round.
 
Well, I took the plunge and got the Girard 2GWHAM aka GSWH-2 and installed it.
I ordered the conversion door for it but it turns out my Atwood had a 'flush mount' door which adds a ton of complexity and I could not come up with a way to solve the issue so I returned the door and removed the existing bezel from the tank and fabbed up an aluminum plate for the cover. I'll have it powder coated white on Monday.

It actually works very well. It took a bit of getting used to. My kitchen sink flows a TON of water (basically unrestricted) so I installed a spray nozzle on the end to reduce the volume. This helped a great deal. My shower head was already a low flow/high pressure unit and it worked very well. Bathroom sink is also not an issue.

So...with 46f inlet water temperature, and the unit set to 124f, I could easily get to scalding temps in the shower with decent flow. Flow being effectively identical to what I had with the tank. The difference is that on max flow (hot tap wide open) the temps drops a bit to just a good warm shower.

It takes a few minutes to get used to it. Normally, if you want more heat in the shower you open the hot valve more. In this case, the longer the water remains in the heater, the hotter it gets. So if you want more heat you close the valve a bit. If you want less heat, you open the hot valve.

Get it? You have to understand that what you are doing is keeping the water in the exchanger longer (more heat) or shorter (less heat).

There is a delay when you change the temperature in the shower. For instance, if it's scalding hot, and you open the hot tap more, to decrease the temperature of the water, it will take a little bit for that reduction to be reflected at the shower head. Or, you could just open the cold valve for faster results.

The flip side is, you can also just set the temperature on the panel to your perfect temp and leave it at that....the unit does keep accurate temps as compared to the setting if you allow enough time for the water temperature to stabilize from the unit, through the lines, to the fawcett.

But here's the thing, at 46f inlet temp (my winter water temp) I can easily get it hot enough to scald me with decent pressure. That, in my book, is a big success as this should be the toughest inlet temperatures it has to deal with. As winter comes to a close the performance should increase as the inlet water temperature increases. Since there are no temperature issues now, what that should mean is just increased flow.

Where it really shines is in the softness of the water. This is readily noticeable. The tank had so much scale imbedded in it that the water was more/less permanently hard unless it was just flushed and that did not last long. Scale is more/less non-existent in the heat exchanger at this point and you can really tell by the softness of the water. Skin and hair are much softer. Also, you can now drink or cook with hot water because there is no brown/black swamp water sitting in the bottom of the tank. That will never occur with a heater based on a heat exchanger because the water has nowhere to sit. The unit is always seeing fresh new water.

The one area where it's not as good as a tank (in the winter) is filling the sink to do dishes. I have to turn the flow down to get very hot water and then let it fill the sink which does take a bit longer. That I can live with because I can also get the sink water a lot hotter than before. I'd guess it takes twice as long to fill the sink. But...it is fully hot water. With the tank the sink would start to fill hot and as filled the temperature would drop due to the volume of water used. That is no longer the case. So there is a benefit there too.

Overall, I'm very impressed with it. One thing I wish people would do is refrain from reviewing it until they have used it for a few days. My initial thoughts were that it was too small and I was disappointed. This was because I opened the hot tap on full and stuck a thermometer under it. That amount of flow was way too much for it to handle and the temps reflected that.

The solution is to work with the system and not against it. And I wanted it to work. Putting a spray nozzle in the kitchen sink helped a great deal because it cut the ridiculous flow rate down. Turns out, my shower head was already perfect for the unit. Bathroom sink is no big deal - no issues there.

With respect to laundry, my washing machine is very modern and does not fill the washer immediately. It tumbles for a bit, then adds water, then tumbles, then adds more. This turns the unit off and on. So during filling it's best to leave the bathroom sink running a bit so that the washer gets fully hot water. On the flip side though, my washer does have it's own heater so if the water is not hot enough it will heat it. So that is mitigated.

Where I think the real benefit will be is in flushing the unit. In my case, the scale is so bad that you have to remove the tank and upend it to flush it. This means removing all the connections and pulling the heating element. That's a lot of work and you usually get wet. Then you have to reseal the wall/bezel and chase down any leaks you introduced in the process. In other words, it's a full afternoon and you never get all the scale out.

With this unit, I used clear braided hose with hand-tight fittings on the cold inlet and hot outlet. In this way I can easily flush the unit, from inside, and set it up in about 5 minutes. You just put a bucket in the compartment with a pump in the bottom, connect the two hoses to the unit, add some citric acid and let the pump run for a few hours. For me, that is a massive benefit. Opening the low point drains in the wet bay does clear the existing water from the lines, so no leaks when removing the lines.

The unit is much quieter than the tank. A nice small woosh when it comes on and effectively no noise when it's running. The freeze protection feature works. It comes on a bit early and works. When the temp gets to about 5c it comes on briefly, heats the exchanger, then shuts off and repeats as necessary.

Wiring it into the existing KIB panel above the sink was child's play. I reused the existing connector at the tank to make removal easier should it need to be done. Unplug the connector, the two connectors to the control, the two water lines and the propane line and it pops right out. This should not be necessary because you can flush the unit from the inside negating the need to remove it unless repairs are needed. The unit is much smaller than the tank and weighs almost nothing, about 20 pounds.

If repairs are needed, I can easily put it on my desk inside and fix it. Service manual was found on the Internet and turns out, it's a pretty simple system.

The most work was in fabbing up the door/panel cover. This is only required when you have a 'flush mount' door. They have replacement drop in doors for Atwood and Suburban heaters as long as the existing doors are not 'flush mount'.

I'm in possibly the worst place for this heater to operate due to the lower ambient and water inlet temperatures. Yet, it's fine. Shower temps (my primary concern) are hotter than before with same flow rate. When I think of the target market in North America, it's clear to me that it would work much better (read higher flow rates at higher temps) geographically almost everywhere else.

It's worth noting that most problems people encounter are where the inlet water temps are too high. Ie, Florida. If your water feed line is sitting in the sun this can cause problems. In a case like that you would want to increase the flow rate to maximum and protect the lines from the heat of the sun.

I do get periodic E3 errors (overheating) and this is due to my running it at the max temperature (124f). At some points when it shuts off it 'overheats', at least, it thinks it is when a certain set of circumstances take place. But this is a soft error and if you wait a few moments for it to cool off it resumes normal operation. I will solve this by changing out the 140f snap disk for a 160f. This should prevent the E3 from coming back but it's a very minor point.

It's also worth noting that typically, in an RV, you want that $350 Remco Pump that flows 5.3 gallons per minute and a nice high pressure. This works against the unit because the flow is too high, at least with my colder water inlet temperatures. As such, in my case, the typical $100 pump that does 3.2 GPM is even too big.....

So there is some thought required. If you were in Florida, for instance, you would probably want that $350 Remco pump to push as much water through as possible. In a hot climate you would have the opposite problem I had. You would have too much heat and could use much more volume.

But now I no longer turn off the hot water tank nor wait for it to heat up. Hot water is always 'on tap'. As far as delay time in getting hot water to the sink/tap - it's irrelevant. In my case, whether tank or tankless, there is always a delay because the cold water in the pipes has to be purged. You also have some control over the delay. If you turn the water on just enough for the unit to come on, you'll get hot water faster.

I am using more water, but since I'm getting it off a pedestal that's OK. Boondocking would require different considerations. Bottom line, otherwise easy install, excellent water temperature and flow in the shower (scalding if you want it) with 45f inlet temperature, very quiet and smooth, cheaper than a tank replacement (by far in my case), flushing is 10,000x easier, and no more turning the tank on and off. Oh, and also, endless hot water and no hydro bill ($20 per month savings as measured in real-time). It would not surprise me if the propane costs were cheaper too. After all, the unit only uses propane when you are using hot water.

But it is different. You have to think a little differently. And I do think, you have to want it to work. Here's some pics
I've been eyeing up the Furrion rather than the Girard only because one member has been using hers coming up on a year without a flaw. Our 6 gallon Atwood is leaking so it's time to replace. What made you go with the Girard?
 
I found several negative reviews on the Furrion and very few on the Girrard. Also, I am not sure the Furrion had freeze protection which is absolutely essential. The Girard appeared to be an American company and had better support and parts availability.

In hindsight, I wish I had just tried the Foggatti. It has everything the Girard has plus is 55,000 BTU's so it has more heating power. But where the Fogatti shines is that you can turn off the 20 minute limit or increase it. You can access the core functions and change them. On the Girrard, you can't. Those limits are hard-coded. The Foggatti and the Girard appear very similar. So much so, I wonder if the same factory in China makes both of them.

On the whole, I love tankless. It's worked out very well for me but it's not perfect. On the other hand, electric bills are about $20 less per month and I do have great showers, although limited to 20 minutes, and dish washing has been improved dramatically.

I descaled it the other day and it was not even required. I'm not sure it even will need to be descaled. But it was easy as pie. For me, it's a nearly perfect solution.
 
Yes, it does. With the caveat that I do get E3 errors fairly often due to overheating. This is exacerbated by my running the heater at 124F but I do like near scalding water. I have yet to address it, in this case I just need to replace the snap disk that they use, which is rated at 140F, and replace it with one that's rated at 160F. That should address the E3 issue but it can be worked around quite easily. Shut the hot off a few moments to let the heat exchanger cool down and the snap disk will then close the circuit once more.

Once I address that, it should be 100% issue-free. Bear in mind, I'm in a colder climate so running the unit at 124F is desirable. Also, if you cook with oil or have greasy dishes, you really do need the hotter temperatures. I recently cracked the Colonel's 11 herbs & spices (for real, not the BS Internet stuff) and so I pressure-cook chicken on an intermittent basis. So good hot water is essential for dishes.

I have done some other work to 'tweak' the water system since the install. Once I got some experience with it I installed a flow restrictor at the unit to permanently reduce the flow to 1 GPM regardless of pressure. This was done because I prefer high pressure water and my incoming water pressure is typically colder than most (Western Canada). My pump is set to cut off at 90 PSI, which for most people is considered very high. In my case my plumbing is 100% PEX with copper crimp rings and rated at a higher operating pressure with hot water. So in my specific case, the plumbing is not the limiting factor.

The reason I prefer 90 PSI is primarily for the shower but it also makes filling the kitchen sink very fast as well as the washer/dryer unit. But the one that really impresses me at 90 PSI is toilet flushing and when you use the wand.

I like a good water system and if you read my earlier posts you will see that I had previously converted my Atwood 10 gallon tank to a boiler @180F using a commercial grade thermostatic mixing valve. That worked extremely well with the only real drawback being electrical/gas usage and the 20 minute wait times for it to come up to temperature in the morning. But the really big drawback to the water heater was the massive scale buildup. Every 6 months, maximum, you had to pull the entire tank to flush it. A wand would not cut it. So the maintenance on that was terrible. On the tankless, so far, I am seeing no need to flush it at all. Granted, it may need a flush in a few years, but I did flush it the other day and it was as easy as mixing a water/citric acid solution in a bucket and using a pump to circulate it for a few hours. Literally a 5 minute job to set up and then walk away. *Nothing* appreciable came out of it but the copper heat exchanger was so clean it looked like pure gold. However, if you have very hard water, such as in Arizona, you would probably still have to do that although it's a nothing-burger compared to flushing a tank.

On the water pressure side, I run off the pump to get my 90 PSI. With a tankless heater you want smooth consistent flow through the exchanger in order to get smooth and consistent temps and pressure. Because I am picky in that respect I put together a custom pump/accumulator that I call the 'pig'. The 'pig' is a 7 or 8 gallon accumulator with a Remco Aquajet mounted on top of a rubber base to dampen vibration. I bypass the pump's pressure switch and electronic circuitry entirely and use a commercial grade Pumptrol pressure switch. This allows me to adjust the cut in and cut out pressures (differential pressure adjustment). So the cut out can be set to 90 PSI and then cut-in can be set to 60 PSI. The stainless braided hoses are there to dampen vibration and noise and they work VERY well as the Remco is so powerful it can rattle the pipes like you would not believe.

The manifold on the pig has a glycerine filled pressure gage to show you the actual pressure on the pump side which makes adjustment very easy. In addition, there is a proper one-way check valve with a low cracking pressure to eliminate the self-filling water tank issue. This is a nice, relatively compact all-in one solution. You can disconnect the hoses, remove 4 screws and take the entire pump assembly out and work on it on your desk.

The dial controller you see in the front of the pic is a Pulse Width Modulated controller. This is a fancy way of saying it's an adjustable computer that turns the pump on and off very quickly as a means to control the pump speed. As you can see in the picture I have it set to 70% which means the pump is limited to running at 70%. This is set at 70% to keep the pressure cycling switches from activating while showering. In other words, when showering, the pump runs continuously at roughly 75 PSI for the entire shower. Between that consistent water feed, and the 1 GPM flow restrictor up at the water heater, the shower is held to a perfect temperature the entire way through. If the pump were to cycle then the shower temp would alter during the shower. The adjustable speed controller means you can eliminate that.

Being able to alter the pump speed by turning a dial is this simple. It gives you direct control over how long the water flows through the heat exchanger. The faster the water flow, the colder the temperature. The slower the water flow, the hotter the temperature. Because in winter the incoming water temperature is so low, the dial is turned down to 30%. This means the pump runs at only 30% which allows the water to remain in the exchanger much longer to bring it up to scalding. In the summer, as you can see, 70% is good because the incoming water temperature is much warmer.

NONE of this is required for the Girard to work well. My park water is consistently 42 PSI and the system will work well with that pressure in winter or summer. But the issue is, for me, lower pressure. I prefer 90 as opposed to 42. This is why I made the pig. But after 6 months or so of use, I have determined the Girard was designed to address the vast majority of RV installs. Most pumps don't make 90 PSI. Most make ~42. The heater works very well at 42.

I would suggest that the average user only needs to install an adjustable water pressure regulator on the water inlet to their unit, and use that ONLY as means of adjusting water pressure.

As far as I'm concerned, EVERY RV must have this feature regardless. It looks like the picture below. This should be considered REQUIRED because parks have different water pressure and you must protect your water system. Not all units have proper PEX with copper crimp rings like mine.

If water pressure is not that important to you, and 42 PSI is fine, then if you set the incoming water feed to 42 PSI the Girard will do everything you want it to. Where this also comes into play is the varying climates your RV may be used in. For instance, in Arizona, in the summer, the incoming water is likely already hot. As such, you could turn the pressure up (60 PSI?) Or, if you are in Colorado in the winter, you could turn the pressure down (40 PSI?).

Either way, when connected to park water, you now have both protection from over-pressure and also the ability to control the pressure going into the water heater.

That little item was about $30 on Amazon. The PWM controller with the dial on it was also about $30 on Amazon. The 7 Gallon accumulator was picked up at Lowes in Canada for about $110 CAD. The manifold on the pig was about $60 CAD. The glycerin filled gage was about $20 on Amazon. The Pumptrol switch was about $50 CAD. The stainless braided hoses were about $50 for 3 or 4 of them off Amazon. The Remco Aquajet, which, unfettered, can easily, and rapidly (!!) pump up to at least 120 PSI (and probably much higher) was $350 CAD.

Oh, and the pump is fed directly from the coach batteries on a 10 gage cable using a 40 Amp relay. So...virtually zero voltage drop. That was $35 CAD and an appropriate 10 AWG inline fuse was installed which was $15 for two.

The reason I go into detail on this is not to convince people to build a 'pig' but just to show the ways and means that they can appropriate if applicable to them. For instance, the entire planet seems to be wondering how to quiet down plumbing pipe rattle from a Remco Aquajet. It's a powerful pump. Really powerful, especially when you uncork it. The answer is the stainless braided hoses. If you have an otherwise good water pump with a defective check valve, you don't need to huck it out. Just buy a nice brass one and be done with it - for life. No more self-filling water tanks.

Everyone *must* have a proper adjustable water pressure regulator. The benefits of being able to adjust that for tankless installs is icing on the cake.

So...don't know what your specific issue is on the Girard, as I don't have time to wade through a plethora of posts, but here's a TON of answers to questions everyone might have in one post :)

But...just to recap. To make the Girard perfect, in my case, it needs a higher temperature ECO switch (read, snap disk) likely set to 160F as opposed to the stock 140F. Ideally, I would be able to turn off the 20 minute timer. If I could do those two things, one of which I can, it would be perfect. Unfortunately, the 20 minute timer is hard coded into the PROM and the only way to fix that is to reprogram the PROM. That too could be done......my experience is that 30 minutes would have been perfect. That's enough time to wash hair, shave and brush teeth if you've been working on a car and have oil/grease.

One more thing, I did replace the propane regulator on my unit as it was the original and was about 20 years old (!!). When I did that, I bought a manometer off Amazon ($50) and set the propane pressure at the water heater to 11" WC with the propane furnace running on full. If you are cheap, like me, you might try and make your own out of silicone tubing and wood. Don't bother, it will blow the water right out of the tubing every time. Spend the $50 and get the proper tool. You should see how beautiful the flame is on my gas stove since doing that. Literally textbook perfect. Also, having the correct propane pressure did make a difference in the operating noise of the water heater.
 

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I found several negative reviews on the Furrion and very few on the Girrard. Also, I am not sure the Furrion had freeze protection which is absolutely essential. The Girard appeared to be an American company and had better support and parts availability.

In hindsight, I wish I had just tried the Foggatti. It has everything the Girard has plus is 55,000 BTU's so it has more heating power. But where the Fogatti shines is that you can turn off the 20 minute limit or increase it. You can access the core functions and change them. On the Girrard, you can't. Those limits are hard-coded. The Foggatti and the Girard appear very similar. So much so, I wonder if the same factory in China makes both of them.

On the whole, I love tankless. It's worked out very well for me but it's not perfect. On the other hand, electric bills are about $20 less per month and I do have great showers, although limited to 20 minutes, and dish washing has been improved dramatically.

I descaled it the other day and it was not even required. I'm not sure it even will need to be descaled. But it was easy as pie. For me, it's a nearly perfect solution.
I'm seeing they all have negative reviews, Girard had 14% less than 4 stars, Furrion has 9% 1 star ratings alone and 15% 3 star ratings and less while Girard has 7% and 13% 3 stars and less. Fogerty is 21% at 3 stars and less, I'm QC at a factory and if we had this percentage of faulty equipment we'd go belly up, what's wrong with the QC on these heaters and why haven't they corrected the known problems and at least give the purchaser a better idea of pressures, flow rate (min and max) to make these work. 500, 600, 700 and up is plenty of money for them not to work properly for years with good up keep
 

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