Looks like I need a new water heater...

[masterplumber]

Some of the residential tankless models don't lend themselves to an RV installation for a couple reasons. First is their configuration - they're designed to hang on a wall, and many times an exterior wall, so they don't fit the existing spot. Not an issue in a new cargo trailer build maybe, but huge in a class B where every inch of space is already utilized. Second, and probably more importantly, they need a higher flow rate of water than most RV pumps supply. And third, which may or may not be an issue depending upon where you travel, many only work below 5000 - 6000 ft elevation.

In TMGs case I would probably just replace it with a direct replacement RV unit, but try and get an aluminum tank. Then drain and flush it every few months, and change the anode rod once a year. It should outlast the van.

 

[Ballenxj]

Then drain and flush it every few months, and change the anode rod once a year. It should outlast the van.

I'll take note of that, but if I use it frequently, won't it flush it's self? I hadn't thought about the anode rod, thanks.

 

[highdesertranger]

the drain/flush is at the low point of the tank. that's where heavies accumulate, the outlet is at the top or close to it. the heavies never make it out of the tank during normal use. highdesertranger

 

[deadwood]

Sometimes it's just a lot easier to replace with what was in there. Kind of plug and play. Pull the old out and the new one goes right in. No need to have to rewire or maybe even re plum some lines to make the new style fit.

 

[hepcat]

Some of the residential tankless models don't lend themselves to an RV installation for a couple reasons. First is their configuration - they're designed to hang on a wall, and many times an exterior wall, so they don't fit the existing spot. Not an issue in a new cargo trailer build maybe, but huge in a class B where every inch of space is already utilized. Second, and probably more importantly, they need a higher flow rate of water than most RV pumps supply. And third, which may or may not be an issue depending upon where you travel, many only work below 5000 - 6000 ft elevation.

In TMGs case I would probably just replace it with a direct replacement RV unit, but try and get an aluminum tank. Then drain and flush it every few months, and change the anode rod once a year. It should outlast the van.

My concern about a non-RV tankless would be how it would stand up to the vibration and shaking it'd be subject to in an RV.  Residential units are meant to hang on a wall, stationary.  A residential unit in RV use could be problematic.

I've never had to replace a propane RV WH because of tank failure.  Like masterplumber, installing a new anode every couple of years, and draining it at least annually seems to be the answer.   The three tanks I've had to replace, I've had to replace because of freeze damage.

 

[dextours]

Another consideration is a tank can provide an additional six gallons of onboard water. When boondocking that could mean an extra day or two out.

 

[Nonni]

I'm new on the forum, and appreciate your expertise. But I will share my experience installing a portable heater in the trailer. I had in mind all its advantages, in this article https://www.newtanklesswaterheaters.com/7-myths-tankless-water-heaters-need-stop-believing/  is well described. Our unit is used for a parked trailer and shares a 7 gallon propane tank with the furnace and stove. Since I'm not the one living in the trailer I don't have any real sense of how often the tank is filled, how much of the use is the furnace vs. the water heater, etc. I do know that I was worried that it would use the propane a lot faster than the 6 gallon water heater that came with the trailer, but it doesn't seem to.

 

[Motrukdriver]

But.. but... a cold shower in the morning is sooo invigorating.

 

[deadwood]

The easiest solution would be to replace with the same model. It would make it a lot easier to install because you just have to unhook the old one and the new one should use the same fittings.

When I did my van it was from scratch so I got to pick what I wanted from the start. I looked at tankless heaters before deciding on an ISO Temp boat water heater that gets heated from either the vans engine coolant while I'm driving or it can be plugged into a 110 outlet while on shore power and heat it with electricity. I like that there is always hot water when I drive but more importantly I don't have to vent the heater because there is no propane to it.

If you were doing a remodel of the van it might be worth looking at all the other options but I still would probably just switch out a new heater for the old and keep it simple.

 

[DangerBird]

Knocking on wood here but our water heater in our small 5th wheel is 25yrs old. We never hook the trailer up to city water and pressure is set to 45psi on the pump with an accumulator inline. When we want a load of hot water, we open the hot valve at the sink(no pressure and let it drip into the coffee pot while the water expands) and run it for 17min for a nice and warm, hot water only shower. We heat water for dishes on the stovetop. Last 40lb load of propane went 35 days running the fridge fulltime and using a stove burner for heat when needed.

-Mike