Tankless Hot Water Heater - LP

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Kewlbreeze

Active member
Joined
Mar 10, 2021
Posts
26
Location
Alvin TX
My Hot water heater (normal 6 gal unit) is leaking and must be replaced one way or the other.

Camping World sells a THWH for $222. (Excel Vent-Free Tankless Propane Water Heater, Low Pressure Startup, 1.6GPM). A replacement for the existing 6 gallon HWH is $400. Makes sense to me to install a THWH.....what am I missing?

The question is:
> Is tankless the way to go nowadays (we had one in our house and it worked great)
> Can it be installed in the same slot where the old hot water heater came out of? I assume that is the right place.
> Are there issues I am not aware of for tankless systems on a RV?
> Is the installation of Tankless as simple as it appears? Are there hidden issues I am not aware of?

Thanks in advance for your input. I searched the forum for answers but could not find any of the answers for my questions...

Dennis
 
At one point in the evolution of tank less water heaters some folks reported inconsistency delivery of hot water, ie. getting a blast of cold water when it should be warm or hot. As I understood it, this had a lot to do with inconsistent and perhaps insufficient water pressure. Some time has passed so perhaps these units have improved and become more reliable. There are likely many posts on this forum on these units that can provide more insight. If a tank less water is your choice for replacement, you might look into Truma, as they offer a unit that combines hot water as a tank less unit and a furnace. Truma also makes quality products.
 
I looked into tankless for my S&B and decided it wasn't for me. "Tankless" doesn't translate to "problemless" and they have their own sets of foibles, pressure being one of them and another is contamination of the exchanger. Look at the spec's carefully, they give a flow rate in GPM but what's the temperature rise to go with that? For the right user they may be a dream come true but when it came down to actually putting one in there were enough trepidations to make me just stick another tank water heater in and get on with my life. The first thing that comes to my mind for a refit like this is what accommodations need to be made to the gas supply. Tankless burners require a much greater gas flow than a tank burner.

Mark B.
Albuquerque, NM
 
Propane is a precious commodity on an RV, I always run everything on electric except for the gas cook top. Electricity is easier to come by than propane.
 
Adding to this thread. My water heater is giving me more problems than I originally thought, see separate thread, I fix one issue only to be presented with another. I have started looking at tankless (propane) and have seen various prices for these, ranging from $1000 down to $150. My hot water usage is fairly minimal being kitchen for washing dishes, shower and bathroom sink, although washing hands with water from the cold faucet is normal, since I am in FL and the cold water is usually warm. The expensive option could be something like a Fogatti LSB64FR whereas a cheaper option could be something like a Gasland BS158N.

The Gasland (or similar) appears to be a tankless shower water heater but I can see no reason why it couldn't be a replacement for a Atwood water heater (gas/electric). Connecting the existing hot water out pipe to the out value on a tankless and connecting the existing cold to the tankless inlet. A gas feed already exists for the Atwood but would need to be adapted . A flow of 1.5GPM would be enough for day to day use, 2 faucets are never run at the same time, there are only 2 of us in the RV

Something like the Fogatti is the normal tankless system for RV's but these do the same job, just slightly quicker and with minimal hot water usage the inconvenience is minor.

Can anyone see a problem with this configuration, using a small Gasland type tankless heater? I am aware that a bit of extra propane might be used, but it takes about 20 minutes to heat 6 gallons of water already using electric, so I would expect a bit more propane use, I have 2 tanks each cost about $20 to fill from empty.

Spending $500 to $1000 on a Fogatti type tankless replacement doesn't make economic sense, I could refurbish my old Atwood for less than $100 whereas $150+ for a smaller new unit is a viable option, if it works.

Anyone have any thoughts or ideas on this subject
 
I think you will find that a 1.5 gpm flow rate is low for a shower, but personal preferences vary widely. Most shower heads are designed for a 2.5 gpm flow and many find that to be less than they prefer.

Note that the Gasland BS158N is an outdoor, portable heater, so not really suitable for mounting inside an RV. However, if mounted where the Atwood was, it could be vented outside.
 
Gary RV_Wizard said:
I think you will find that a 1.5 gpm flow rate is low for a shower, but personal preferences vary widely. Most shower heads are designed for a 2.5 gpm flow and many find that to be less than they prefer.

Note that the Gasland BS158N is an outdoor, portable heater, so not really suitable for mounting inside an RV. However, if mounted where the Atwood was, it could be vented outside.
Click to expand...
It would be mounted where the Atwood is which is accessed via an outside door. I think the lower gpm flow should be ok, the current flow isn't great but it does the job. The Gasland was an example, I would be shopping around for before buying, if I decide to go this route. My main concern at the moment if using a Gasland type system would work or does it have to be a full blown Fogatti type system. My thoughts are that they both the same job, one is more powerful than the other.
 
Much has been written about tankless RV water heaters here and elsewhere, so I suggest a search of previous topics and the internet in general. You might try YouTube for some reports. Here is one such.

In my view, going tankless was all the rage a year or two ago, but now those who made the switch are beginning to post reports that sound like they are somewhat disappointed. Apparently it's not the panacea they expected. Like anything, there are both pros and cons.

One of the drawbacks is the delivered heat varies with the incoming water temperature. Living in Florida helps with that, but there is still a noticeable difference if you happen to camp on a 60 degree day vs 90. Another is that the propane burner has to fire up every time you draw hot water. Even a few ounces. Some find that irritating, while others couldn't care less.
 
Kewlbreeze said:
The question is:
> Is tankless the way to go nowadays (we had one in our house and it worked great)
> Can it be installed in the same slot where the old hot water heater came out of? I assume that is the right place.
> Are there issues I am not aware of for tankless systems on a RV?
> Is the installation of Tankless as simple as it appears? Are there hidden issues I am not aware of?

Thanks in advance for your input. I searched the forum for answers but could not find any of the answers for my questions...

Dennis
Click to expand...
Tankless - Technology has certainly moved along. My issue with tankless is power consumption whether gas or electricity. The colder the water goes in the colder it comes out or the longer it takes to heat - i.e. lower flow. I agree with John C that I am usually closer to electricity than I am to propane fill ups so check the consumptions.

Secondly I like the option of both electricity or propane. I recently did a bunch of parts replacement on my Propane Atwood 6 gal. I also stuck in an electric "Hot Rod" electrical conversion. Totally happy with it.

Installation - I am guessing there will need to be some adaptation - You may need to talk with the seller and tell them exactly what you are replacing. It could be a bolt in replacement but I don't know.

Simple? - Depends on the factors above that I mentioned.

Price - $222 bucks seems like an inexpensive solution to the current problem. I personally would invest the $400+ and "upgrade" from propane only to propane + electric.
 
I would never consider tankless for an RV for several reasons. If you boondock, you are wasting water. If you are on shore power, electric is less of a hassle than getting your propane tank filled.
 
the main problem with tankless water heaters was inconsistent water temps when not hooked to campground water. you need to upgrade to a water pump with 60 lbs pressure, and a ballast tank. the tank will stop the pump turning on and off.
i have had several models of the girard heater, and with the new rheostat temp settings, we have endless water at about 102 degrees. the pump makes all the difference.
i do not work for girard. i have been their tester for several years.
what they have now works the way it should if you add the pump and tank.
paul maddox
 
pfmaddox said:
the main problem with tankless water heaters was inconsistent water temps when not hooked to campground water. you need to upgrade to a water pump with 60 lbs pressure, and a ballast tank. the tank will stop the pump turning on and off.

paul maddox
Click to expand...
The "ballast tank" is intriguing. I know at times when using water from the storage tank the shur-flo pump will cycle rapidly if only using a little water. Would a small tanks like this, Amtrol Well-X-Trol WX-101 In-Line Well Pressure Tank 2 gal , help minimize cycling? I assume you would install it right after the pump discharge. Seems like a good idea.
 
sorry to be slow in responding. yes, anywhere you have room near the pump will work. i bought a big flojet pump. it puts out 50 lbs if you adjust the pressure switch. the pressure is the answer, as long as the ballast tank takes care of the on/off action of the pump.
 
Got a small accumulator tank on its way. I will install before next camping trip in two weeks and let yinz guys knows how it performs. Stay tuned!
 
Complete tankless systems are not ordinarily used for all purposes like for showers. I have used many tankless systems over the years. Each installion and use was either laundry supply or sink supply. Showers were always given the stability of storage.

My personal RV set up includes a Bosch 4 gallon electric 1440 watt instant hot which I use when plugged into shore power. The Bosch makes good fast hot water but still will cool down some from extended runs at the shower head. It does recover very quickly though and has been an outstanding addition to my hot water system. I have additional plans to install a circulator pump in the system as well. A circulator pump creates storage in the plumbing without using a tank. It uses the delivery piping for storage which can be the difference of cooling water at the shower head or a consistent flow of hot shower water.

Instant hot water systems allow for less storage. The quicker the recovery, the less water you will need to store. I don't think there are any systems that I would rely on without storage and if I did attempt a tankless, I would keep my onboard storage system for a backup which would seem to eliminate the primary advantage of going tankless. Storage is always good. Especially when taking showers.

The other issue with a tankless is the dependability. I remember having a problem keeping the gas units running. There are a series of safety valves built in to prevent raw gas from venting into the living space. There were always problems with those valves. Maybe those problems have since been eliminated but I still would experiment with a tankless before scrapping the convetional storage system.
 
Last edited:
Henry J Fate said:
Complete tankless systems are not ordinarily used for all purposes like for showers. I have used many tankless systems over the years. Each installion and use was either laundry supply or sink supply. Showers were always given the stability of storage.
......
Click to expand...
Whole house tankless systems are quite common in Texas at least. We had a Riannai tankless in use for about 18 months for the house until our February Ice-apocalypse and losing power. The Riannai's internal circulation pump was off and the heat exchanger burst. Now we have a Navien tankless.

Tankless heaters are sized according to GPM requirements, our Navien will supply at least two showers. These are either natural gas or LP, the electric versions use a tremendeous amount of current and not that practical for whole house.
 
John Canfield said:
Whole house tankless systems are quite common in Texas at least. We had a Riannai tankless in use for about 18 months for the house until our February Ice-apocalypse and losing power. The Riannai's internal circulation pump was off and the heat exchanger burst. Now we have a Navien tankless.

Tankless heaters are sized according to GPM requirements, our Navien will supply at least two showers. These are either natural gas or LP, the electric versions use a tremendeous amount of current and not that practical for whole house.
Click to expand...

That's positive news.

What would be the typical fuel savings with a gas tankless compared to a traditional gas with storage and do you use a generator to power up the tankless during outages?

Not being able to heat water with electric would seem to be a disadvantage in most RV applications especially when electric is included in the site fee. The other disadvantage is not be able to take advantage of a heat exchanger if in a motorhome. (which I know is seemingly headed to the same grave yard as the 12 volt refrigeration option but is still working fine in mine)

Having 3 sources of hot water is quite wonderful but 2 sources in most mobile applications would seem to be standard and probably the best design (electric and gas).

I guess this all comes down to the difference in equipment price, the space gained by having no storage tank and the cost of energy. The bosch 4 gallon instant I added is priced about $180. I picked mine up for $50 from a failed experiment and about new. My atwood gas 6 gallon I think is priced around $400 without the exchanger but have not looked recently and is original 2001 equipment. Since I have both systems up and running, going tankless doesn't make any economical sense and less sense when I consider that we rarely pay for electric and enjoy not worrying about filling the propane tank and of course the heat exchanger. In the colder months we use electric heat when free electric is available and rarely fire the gas furnace which reduces the need for tank filling.

I did notice that last winter the Bosch instant had some trouble keeping up as the incoming water temps went down. We did fire the Atwood for a boost a few times instead of raising water temperature. I have the 2 tanks in series. The Atwood flowing into the Bosch. Soon my circulator pump will be installed and will offer close to 12 gallons of pre-heated water with electric and gas available for a quick recovery. My hope is that the circulator pump allows the bosch to handle the demand year round.
 
All tankless heater have a maximum temperature rise. I've seen cheaper models that have a 40° rise and better ones with a 60+° rise. The higher temperature rise accompanies a higher BTU rating.
The larger units also have a higher minimum flow rate for the burner to operate consistently.
 
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