Tankless vs Tank Water Heaters for Full-Time Park Stays

[grndslm]

Not sure if there's a better place to post this...

But I'm looking to purchase a "new-ish" camper, most likely sub-30 ft... and I see that in the past few years, almost ALL manufacturers have swapped to instant / tankless hot water heaters. There's some sporadic models that still have tanks, but my understanding is that Ember Overland has stuck with the Truma Combi (~2.5 gallon) and Rockwood/Flagstaff has stuck with the 6 gallon gas/electric tanks. If money was no object, I'd probably prefer to buy from these brands regardless of this hot water question....

It just so happens that the used campers that are a few years tend to still have the 6 gallon tank water heaters for the most part.... but there are some decent deals on the tankless water heaters also, because they're just so prevalent and plentiful now.

I guess my question ultimately is... does this even matter?? One reason to prefer the combo (120v electric) is that I'm going to be docked at a park 99.8% of the time.... so why would I want to pay extra $$$$ to refill my gas tanks if I can make it with a 2.5 gallon or 6 gallon tank. It will MOSTLY be just me, but I'm sure there will occasionally be somebody else. I'm pretty conscious about things like this, so I'm thinking it'll be a non-issue.... I'm just wondering.... how long will the propane actually last in a 60k BTU tankless setup (that hopefully doesn't have any leaks) if I'm taking a 5 to 10 minute shower every day?? I'm guesstimating needing to refill once every month or 2, but I saw a comment of someone elsewhere on the Webz, and he said he went like 9 months before needing to refill.

As I stated, if money was no object, I'd probably get an Ember Overlander and also install an all-in-one washer/dryer since the 2026 models with the bunk/E-track system are all supposed to have W/D Prep.... but in all honesty, paying even $5 a week at the park to wash a load is chump change versus the upfront cost for a new camper + W/D equipment.

Am I overthinking this? I'm paying $550~600/mo for long-term rates that include unlimited water & electricity.... am I being a little too salty about paying even $20/mo to refill propane to heat as much water as I want? ... or is my initial thought process that 6 gal (and possibly even 2.5 gal) tanks are more than enough for me and I should stick to them until I win the lottery?

 

[woof-n]

Your propane hot water cost will be your smallest camping travel expense. I would not let the water heater decide what camper to buy. Good luck

 

[RV_Lee122]

I turn on my 6G, either propane (boondocking) or electric (at an RV park) and turn it off once its heated up, it stays hot for hours - doesn't need to be left on. When RV shopping I said my first mod was going to be install a tankless, it has not been needed. When it has a tank of heated water thats when I shower and do dishes, beyond that hot water isn't even needed. Just speaking from experience.

 

[DonTom]

I guess my question ultimately is... does this even matter??

Yes, tanlkess water heaters are the dumbest things ever installed in the newer RVs, IMAO.

Be sure to read my thread here.

-Don- Reno, NV

 

[John From Detroit]

One thing sometimes you want a "Slow flow" of hot water.
Tankless don't do that. You need enough flow to flip the flow switch)

Read furnace threads that mention "Sail switches" A flow switch is the same thing but for water. Some need over 1-2 GPM one CG I was at hat tankless and if ONE person was taking a shower.. NO hot. had to have two showers running.

 

[Lou Schneider]

Tankless water heaters are very inefficient, the water simply isn't in contact with the flame long enough to absorb much heat from it - most of the heat goes straight out the exhaust. A tankless heater either needs an excessively large flame or has to restrict the flow rate to the heat it can supply.

Propane contains 90,000 BTUs per gallon, so a tankless water heater with a 60k BTU flame will consume 2/3 gallon of propane every hour the flame is on. A 30 minute shower will use 1/6 gallon, etc. This is 2-3 times as much heat as a typical RV furnace, BTW.

Because tankless heaters waste so much heat you won't find any that can operate from an RV's electric supply. A kilowatt-hour produces 3.4 BTUs so you need 17,600 watts of electricity to produce 60k BTUs. That's 150 amps at 120 volts or 75 amps at 240 volts, well beyond an RV's 30 or 50 amp service capacity.

Both of my trailers (DRV at my home base and the Arctic Fox I travel in) have 12 gallon Suburban gas-electric heaters. I usually take Navy showers but never have run out of hot water if I let it run.

 

[Kirk]

My wife & I did just fine with an 8-gallon tank type water heater in our fulltime RV for 12 years and with only 6 gallon in the RVs before and after that. The 6 gallon one did take a bit of planning if we both wanted to shower at the same time but the 8 gallon, not so much. The water heater doesn't use a lot of propane whether you leave in on all of the time or only turn it on a couple of times a day. By far the biggest propane user is the furnace and without serious cold weather we usually went 6 months or more on our propane supply. But even that is not a standard thing since the size of propane bottle can vary widely. Trailers come with 20#, or 30# bottles and usually two of them. You can also easily find tank type water heaters that have the ability to heat from either propane or electricity.

 

[DonTom]

You can also easily find tank type water heaters that have the ability to heat from either propane or electricity.

Or add a Hott Rod as I did in my Y2K RV.

-Don- Reno, NV

 

[Alaskansnowbirds]

My wife & I did just fine with an 8-gallon tank type water heater in our fulltime RV for 12 years and with only 6 gallon in the RVs before and after that. The 6 gallon one did take a bit of planning if we both wanted to shower at the same time but the 8 gallon, not so much. The water heater doesn't use a lot of propane whether you leave in on all of the time or only turn it on a couple of times a day. By far the biggest propane user is the furnace and without serious cold weather we usually went 6 months or more on our propane supply. But even that is not a standard thing since the size of propane bottle can vary widely. Trailers come with 20#, or 30# bottles and usually two of them. You can also easily find tank type water heaters that have the ability to heat from either propane or electricity.

What's the difference in water usage if you take a shower by yourself or you both take a shower at the SAME TIME?

 

[Edd505]

What's the difference in water usage if you take a shower by yourself or you both take a shower at the SAME TIME?

Have not seen an RV with a large enough shower but at home we have a large dual head shower. I like the tankless for long showers but they take a lot of water to get the hot flowing, I can watch the temp raise on the wall unit. We only unitize full hookups so it's not and issue for us as we never boondocks more than a quick rest in a rest area or wide spot is we get sleepy.

 

[Kirk]

or you both take a shower at the SAME TIME?

That takes longer? I guess it just depends on who washes what.

 

[Edd505]

That takes longer? I guess it just depends on who washes what.

Some times

 

[Firstime RVer]

I don't know about you guys, but I have a 6 gallon water heater. When I want to take a long shower, I turn both the electric and propane heaters on, and have yet to run out of hot water. With both turned on my system works essentially as a tankless heater.
Don't see any need for a tankless, and love the flexibility of having both propane and/or electric water heat sources available.
Just my $.02 FWIW
Safe travels and all the best.

 

[DonTom]

I don't know about you guys, but I have a 6 gallon water heater. When I want to take a long shower, I turn both the electric and propane heaters on, and have yet to run out of hot water. With both turned on my system works essentially as a tankless heater.
Don't see any need for a tankless, and love the flexibility of having both propane and/or electric water heat sources available.
Just my $.02 FWIW
Safe travels and all the best.

That is what I do with my Y2K RV. But in my 2022, the tankless cannot run from electricity. Another one of the countless reasons why tankless are to be avoided in RVs.

-Don- Auburn, CA

 

[RV_Lee122]

I don't know about you guys, but I have a 6 gallon water heater. When I want to take a long shower, I turn both the electric and propane heaters on, and have yet to run out of hot water. With both turned on my system works essentially as a tankless heater.
Don't see any need for a tankless, and love the flexibility of having both propane and/or electric water heat sources available.
Just my $.02 FWIW
Safe travels and all the best.

I let the propane run for around 10-15 mins, this gets the water just right and you dont need to add any cold to the mix. I've also never run out of hot water.

 

[Gary RV_Wizard]

Personal habits differ and some people seem to run short of hot water with 6 gallon heaters. However, very few complain if they have 10 gallon heaters. The ads for tankless brag about endless hot water but of course don't mention the shortcomings described here. And RV manufacturers love the space savings and simpler (cheaper?) installation, especially in smaller or entry level RVs.

If I were buying an RV today, I'd stick with a tank type heater. 10 gallon size. Or if the rig was a DP, a hydronic system that provides both heat & hot water using combo diesel or electric heat.

 

[DutchmenSport]

6 gallon electric/gas water heaters on my first two travel trailers. Me, wife, and 2 dogs never ran out of hot water. Short showers, and showers not taken back-to-back resulted in always have hot showers with more than enough warm water.

Third travel trailer had a 10 gallon gas/electric water heater. Showers got longer, but still limited by the size of the grey water holding tank.

Fourth (Fifth Wheel), 12 gallon gas/electric. The change? We now take showers back-to-back often and still never run out of warm water.

The distance the water heater is from the faucet has a lot to do with how much "waste" water is run before the shower, or the bathroom, or the kitchen sink, or the outside shower gets hot water. Regardless if it's an on-demand or a 6, 10, or 12 gallon tank, the cold water standing in the pipes have to be bleed out first until the hot water coming out of any tank reaches the faucet. That distance does not change. The difference is, an on-demand water heater requires the water be turned on at full force so the water heater will kick on. Then it has to bleed out the cold. However, if the flow of water is now reduced to a trickle, the on-demand heater shuts off, and now ... cold water again.

A conventional water heater, no matter how fast or slow the water is running, it's always hot water coming from the heater which will continue to flow to your faucet.

I do not ever want an on-demand heater for these 2 reasons. Slower flows won't produce any hot, and the distance to travel makes no difference.

The only advantage of an on-demand is, if the water is running full strength, it's endless. Eventually, a conventional water heater will displace it's hot water with cold.

Another thing, if winter camping, water coming into the camper could be barely above 32 degrees. The on-demand water heater is going to heat that water up only so much. You could still be taking a cold shower.

A conventional water heater will always heat the water up to temperature, no matter how cold it is when it enters the tank. Mixing the water at the shower between hot and cold will require the hot to be more and the cold less, as the cold is near freezing. It take more hot to keep it at a comfortable temperature.

In the Summer, the incoming water could be 80 degrees. It take a lot more cold water to keep it at the same temperature.

On demand heaters don't do this. The water passes through at a specific speed, and the colder the water is at intake may not have enough time to heat adequate at output.

Think about it.

 

[Brad Buchanan]

Your propane hot water cost will be your smallest camping travel expense. I would not let the water heater decide what camper to buy. Good luck

That is really not the big factor.

When the DW and I were in the 5th wheel and using hot water for showers and dishes we were going through a 100lb tank every month, more or less.

 

[woof-n]

That is really not the big factor.

When the DW and I were in the 5th wheel and using hot water for showers and dishes we were going through a 100lb tank every month, more or less.

100lbs or 20 gallons of propane is over 2,000,000 BTUs That is a lot of hot water.

 

[DutchmenSport]

Since we're "pinching pennies" here, an RV On-Demand heater uses propane. A conventional gas / electric heater uses both propane and/or gas. If connected to electric shore power, there is no need to run the conventional water heater on gas. It runs perfectly fine on electric. Why pay for gas for the water heater when most campgrounds include electric in the campground fees? It makes no sense to pay double, so run the water heater in electric and save your gas expense.

Now, if you are on a site where you pay electric separate from the campsite fee, then that could be a different matter. Or if parked at home where you pay your own electricity anyway. Still, over-all, electric is still a bit cheaper than propane. (IF you are counting pennies ... something else to think about).