RV Tankless Water Heaters Compared To Standard RV Water Heaters

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rv-shower-by-Larry-Page.jpg The standard water heater in most RVs is an LP unit that holds 6 gallons of water and keeps the water at a set temperature.

This is acceptable for the camper who goes out for the weekend and wants to be able to wash the dinner dishes with the same ease that they’re accustomed to at home.

However, for the family that’s staying at a resort for a week with a couple kids, this isn’t the most user-friendly situation.

Not to mention the fact that full-time RVers become accustomed to taking daily showers.  Depending on the size of your family, it could turn into an all-day process just to cycle each person through the shower and wait for the water heater to recover each time.

To make matters worse, 6 gallons of hot water is only enough to take you to about the point where you’re covered with soap from head to toe.  Then it cuts to cold when the hot water runs out.  That final rinse can be downright chilling!

Fortunately, RVers have a few alternatives…


Larger 10-Gallon RV Water Heaters

A huge improvement is the next step up with a 10-gallon water heater.

My wife and I lived for 3 years with this size and found that it supplied enough hot water.

Plus, by reducing the water flow a little bit, you could take a shower with the water running continuously.  If you hustled, you could finish without it going too cold during the final moments.

Of course, we still had to wait an hour for the water heater to get back up to temperature for the next shower.

Wouldn’t it be nice to be able to take as long a shower as you’d like?  Then to be able to have another person take their shower as soon as you’re finished?  Then to be able to wash dishes or send a load of clothes through the washer/dryer immediately after everyone is done in the bathroom?


RV Tankless Water Heaters

Tankless water heaters are becoming the accepted way to heat your water in today’s new home construction market.

Though they aren’t standard equipment on most RVs at this point, they are available for the RV market  too.

With propane burners and the sensors powered by 12V DC, an RV tankless water heater will work exactly like the one you may have at home. As soon as you open a faucet and water flow is sensed, the burner ignites.  In a matter of a second or so, hot water is coming out of the faucet.


Pros & Cons Of Tankless RV Water Heaters

The cost of a tankless RV water heater is a bit higher than a regular RV water heater. You’re looking at around $1,000 for an RV tankless water heater, compared to about $800 for a standard 10-gallon RV water heater.

The question that immediately came to mind for me is what happens when you’re not hooked to city water?

Operating off your onboard fresh water supply, how does it know when you’ve run out of water?  Ignition for the unit is controlled by a flow meter.  A spinning blade of sorts turns as water flows through the unit.  At the point that you run out of water, the spinning component no longer turns because water is no longer passing by. At that point, the burner will shut off or refuse to ignite, rendering the system safe until water flow is again established.

Much to the delight of RVers who are living Green, a tankless RV water heater will consume less fossil fuel than the standard RV water heater that ignites and keeps 6 to 10 gallons of water piping hot, regardless of whether you’ll be using it or not.

For those who go boondocking for extended periods of time, propane consumption is a big deal.  Stretching your supply means fewer trips into town to get refilled.

It wouldn’t take much time at all to make up the difference in price between an environmentally friendly tankless RV water heater and the standard 6- or 10-gallon RV water heater.

Maybe it’s time to upgrade…
More About RV Tankless Water Heaters


I’ve been involved in RVing for over 50 years — including camping, building, repairing, and even selling RVs and motorhomes. I’ve owned, used, and repaired almost every class and style of RV ever made. I do all of my own repair work. My other interests include cooking, living with an aging dog, and dealing with diabetic issues. If you can combine a grease monkey with a computer geek, throw in a touch of information nut and organization freak, combined with a little bit of storyteller... you’ve got a good idea of who I am. To date, I've shared my RV knowledge in over 300 articles here at The Fun Times Guide! Many of them have over 25K shares.

19 thoughts on “RV Tankless Water Heaters Compared To Standard RV Water Heaters

  1. I have a basic question – what happens to the exhaust fumes from an RV water heater, is there an actual flue pipe? I have one at a cabin and I’m wondering if I can mount it indoors so that I can use it in Winter (Nova Scotia) but I guess I would have to modify the flue pipe to take it through the wall. Do you think this is feasible?

    1. Graham, RV water heaters don’t have a flue pipe so to speak. The exhaust exits out through an opening in the access door. You would have to cut an opening say about 14″ square (estimating) and mount the water heater as a unit in that opening just like it is mounted in an RV.

    1. Rrr, No, they’re fairly new in the RV world so I have only had exposure to one brand and it was a portable model. I know you can buy units that mount right into the RV now.

  2. Had 10 gal water heater for 8 years and never ran out of hot water, used very limited propane as we turned it off when moving or away from the campsite for the day. Insulation was excellent and it kept warm enough to begin dinner dishes while burner caught up. Ours was gas/electric and if we wanted hot water faster and we had electric, we turned on both – 15 minutes max to full hot water.

    Now have Precision brand tankless in our present coach and find it excellent also. Major negatives are a requirement to drain and winterize it when moving on a sub 32 degree day and, when boondocking, navy showers can result in a chill until flow triggers the heater. Means I take less time soaping up with water off so water in the pipe doesn’t cool off too much.

      1. Dear Curtis,

        Home Depot doesn’t even come close. I’m looking for the exact one pictured on that web page. Thanks!

  3. I don’t know where he found a $1,000 tankless hot water heater, but I’ve seen them for less than a third of that price.

  4. Curtis, my wife and I are in Texas and thinking about long term rv-ing. Hot water has been a concern of mine for our teenage daughters. Any recommendations would be appreciated!

    1. I think the bigger concern is Wastewater capacity. Unless you intend on spending every night in an RV park that provides full hookups , accommodating all those showers is going to be difficult. I recommend short hair and navy showers. Recovery time on a standard water heater is about 10 minutes. Of course a tankless water heater will give you all the hot water you want but do you have a place to put all that hot water?

  5. My first RV (purchased used) was a Blue Bird Wanderlodge that came with an AquaHot system that supplied domestic hot water, hydronic heating (interior and “basement” of the RV), and an engine pre-heat system that made starting the diesel quite easy even in below freezing weather. As with any tankless system, it provided “endless” hot water. The AquaHot ran on diesel from the main fuel tank. Webasto also makes tankless hot water heaters similar to those from AquaHot. Both Webasto and AquaHot heaters tend to be on high end RVs — because they are very expensive units and generally would be difficult if not impossible to retrofit to an existing RV.

    I now have a 2011 Roadtrak (Sprinter Van) RV. The Roadtrek is a Class B — i.e. it is a “van conversion” not a Class C where the chassis is used. The significance is that there is extremely limited space. It came with a typical 6 gallon hot water heater. I replaced mine with a Truma tankless hot water system — Truma offers 3 models, the “bottom line” and a “middle line” model that can be retrofitted into existing RVs. The “top line” is only for OEM installation. I ordered the middle line unit. It has “freeze protection” and “instant” hot features not available on the bottom line unit (and adds slightly to the price). These features (which are related) adds a tiny “tank” (holds about a cup of water) and a recirculation pump that allows the unit to cycle hot water internally if below freezing temperatures are encountered (in the hot water heater compartment). This feature also allows an initial “shot” of water to be sent to the faucet “demanding” hot water, making the initial receipt of hot water to be less than 15 seconds (time taken to clear the cold water out of the water line). Without this feature, the unit might take up to 30 seconds for acceptably hot water to be received. There are also tankless hot water heaters from Girard and Atwood — and possibly some other companies.

    It is important to understand that installing a “home” tankless hot water heater is probably a poor idea, since the water pressure and flow is lower in an RV (especially when using the internal pump). And home units also require very specific venting for safe installation of propane units. A particularly small electric tankless system that is electric only might be installed, but it would require wiring and a 50 Amp connection (they require 220 volt service) making them less than ideal under many typical RV camping situations.

    There are some RV tankless hot water systems that work as portable unit, with set up outside.

    As for the wastewater, in my Wanderlodge, the gray water capacity was about 100 gallons, so that accommodated several showers quite easily. The Roadtrek is rather less generous with a gray water capacity of 21 gallons — but I’ve not “overflowed” the gray tank, though I prefer to have a full hook up when using the shower in the Roadtrek.

  6. I have bought a very old and totally ruined 1982 lindy motorhome and would love to pick your brain for some ideas Curtis if that would be ok. Please contact me if possible not sure how to send any personal messages on this site but my idea is to tear the whole trailer off the cutaway so i can have a mechanic go through it then build a tiny house and workshop on the body. I’m trying to find out the max dimensions i will be able to build and i need to be able to boondock.

    1. That sounds like a fun project. This is the place to ask your questions, feel free to ask away. The maximum dimensions are 8′ 6″ wide by 13′ 6″ high. You have placed your question to an article about tankless water heaters So I highly recommend that as a way to go. Boondocking I highly recommend solar panels For generating electricity. I currently have 500 watts Because I am living totally off grid myself. Feel free to ask any question you have right here.

      1. what kind of frame do you suggest? I heard somewhere if i do my own welding it might not be able to be inspectable, any thoughts? I also love the idea of a tankless water heater i was trying to talk my wife into that before our separation. Do you know the current max for length? i think it is 24′ atm is there any restrictions on expanding it? i was also looking into habor freight for the solar system. How about your wifi needs while boondocking how do you supply that? I love to watch kodi so a lot of streaming.

        1. Type of framework is your choice. Many rvs are built out of 2 by 2 construction with cheap paneling.Of course they self destruct in an accident. To the best of my knowledge length is limited to 45′ over all. Don’t take that as gospel but the point is whatever the trucj frame of your vehicle is will be fine. Do not waste your time or money with Harbor freight solar panels they are a joke. Renogy Is a well known brand name in the rv world. Be prepared to pay at least $1 to $1. 50 per Watt. I have a cell phone with unlimited data and use that as a hotspot to my laptop. If I have a cell signal I have wifi. I also have DirecTV satellite television Which allows me to watch it on my cell phone as well at no additional charge.

          1. Curtis thank you for your help i cant wait to embark on this journey of remodeling this vehicle i have done many construction projects but never a vehicle so this will be a great adventure i hope, lol. Thanks for your review of the harbor freight panels that is a blessing to find out before hand. i am probably going to use metal stud framing from my camper build as i have always wanted to build my house that way. Any suggestions on insulation with soundproofing properties? I have thought about a heavy floor liner sandwiching bubble wrap. i live in the northeast and unsure if that will be enough for the winters.

          2. I recommend Styrofoam insulation, 4 by 8 sheets Cut to fit wherever you need it. The biggest reason is moisture will not hurt it. If it gets wet once you dry it out it is good as new.

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