Hot Water Heater Options

[richard5933]

Our 4106 is basically an all-electric coach, other than the diesel generator and diesel powered Webasto. Our current water heater is a 6-gallon 120vac unit bought at a local box store. It works well but has limitations. The main limitation is the necessity of having 120vac to make hot water. For many reasons, we're trying to limit the amount of times we run the generator as we move to adding solar next spring. The solar plus a larger battery bank should enable us to remain unplugged for most everything we need, other than hot water for washing & showers.

So far, I see the options listed below. Each has its pluses and minuses. I would love some feedback or suggestions for options I'm not considering.

1. Maintain the current system and just deal with running the generator as needed.

2. Install a marine hot water heater that runs on either 120vac or by running coolant through the heat exchange. This would of course give us hot water whenever the bus engine is running. It would also give hot water anytime we're running the Webasto. The up side of this is that no additional venting or plumbing is required other than adding another few pieces of heater hose to loop the Webasto. The Webasto and hot water heater are about 12" apart, so this would be easy. Down side is the potential for water contamination should there ever be a leak in the heat exchange. Also would mean that we'd essentially be forced to run the furnace whenever we need hot water, even in the summer. And, if the temp is over the upper limit for the thermostat the Webasto won't even fire unless I add a jumper to the system to bypass the thermostat.

3. Add LP to the bus and install a 120vac / LP hot water heater. Definite plus would be having hot water whenever we need it without shore power or generator. Big down side is having to move the water heater to a location against the bay door so that it would be possible to vent. (Current location is in center of bay) Would require cutting new venting for the LP burner, and would require add LP tank, regulator, and all necessary plumbing. Not too keen on adding another fuel and on having the LP tank onboard.

4. Solar hot water on roof. Haven't done too much research on this, but I imagine it's possible to install a smaller version of what's used throughout many parts of the planet to make domestic hot water. Would require some fancy engineering if I was to camp in colder seasons, which we plan to do. Would also require lots of new plumbing and would be a major project.

5. Heat a pot of water on portable LP range for washing. We've done this when the generator wasn't cooperative, but it's pretty hard to get a shower from a pot of water. If the trip had been more than a long weekend I'd be traveling alone from then on.

Does anyone know of a diesel fired hot water heater that is direct fire and not a heat exchange system?

Any other systems out there I'm not aware of?

Thanks.
Richard

[Lee Bradley]

Even if you find a diesel fired water heater, you would have to vent it.

Maybe one of these http://www.doctordiesel.com/index_files/page0003.htm

[richard5933]

Even if you find a diesel fired water heater, you would have to vent it.

True, but assuming that it 'vents' the same as the Webasto, all it would need is a fresh air intake (easy) and an exhaust pipe run through the floor of the bay and out to the side of the bus (also easy).

The LP water heaters usually require mounting against an outside wall, and then they have that goofy looking intake/exhaust panel that goes on the outside of the bus.

Richard

[PP]

After much consideration when we faced problems with our old water heater which was a 6gal gas/elect mounted in the middle of the bus with a vent system to the outside, we replaced it with kind. Except the new one also has a heat exchanger that we could connect to the engine cooling system or some other such as a Webasto that we don't have and probably never will. I thought instant hot water would be great, but 120V systems seem to be a joke and gas require extensive venting. I am very pleased with our new water heater and have yet to run out of hot water during a shower. It maintains hot water with the electric side, but kicks on the gas also when using it for quicker recovery. Of course, there are switches if you prefer just running off one or the other. Solar on the roof might be an option, but not here where it freezes every night, even in the middle of summer. Soon to be out of here, though. Hope that whatever you decide on you are happy with, that's the main thing. There probably isn't anything that doesn't have a compromise of some sort. Good luck. Will

[richard5933]

Will - Can you describe how you vented an LP water heater from the middle of the bus to the outside? Maybe I just haven't found the correct unit yet, but the ones I've seen seem to indicate that the preferred way to install is against an outside wall.

Richard

[Scott & Heather]

Funny because Richard we are in the exact same boat. I have a 40 gallon electric water heater with two 2000 watt elements wired to two different breakers. When on the pole, we have 4000 watts of heating power which allows our tank to recover quick. 150°F water lasts a long long time so we've never run out. But when on genset, I only run one element to keep it hot. Recovery is slower of course but it works. I'd absolutely love a propane water heater tho. At that point my fridge and pump and lights are all that need juice. So I'm watching this thread with interest


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[chessie4905]

We had a marine style water heater in our 4104 and it worked great.True if a failure ever occurs,you could get antifreeze in your water. Highly unlikely though. To prevent that slight or remote possibility, just never use hot water for cooking or consumption if that is a concern for you. Other than that issue, it worked great. The coach would heat the water on the road, and it would stay hot for a couple of days while using without turning on the electric element. I would not hesitate to use one again. Current coach has a regular heater from previous owner. Will replace with marine type when it fails. If you have a large enough generator you could use a high wattage element to heat quickly. Then turn off when up to temp.

[Lifes2short4nofun]

I am in the middle of freshening up a 5B for us to use.  It had a LP 6 gal which wasn't enough supply.  Today we installed an on demand LP,

[buswarrior]

Use the existing Webasto, get a flat plate heat exchanger, use the existing Webasto pump circuit, plumb the exchanger inline with your heat supply tank so whenever the Webasto is firing, you get access to making domestic hot water, and a new pump to circulate domestic water thru the exchanger.

Here's just one of many Google results:  http://www.supplyhouse.com/Heat-Exchangers-821000

Simple to add a bypass wire to fire the Webasto, circulate the heat and not send any heat into the coach.

No need to add anymore parts, you have most of them now.

happy coaching!
buswarrior

[richard5933]

Buswarrior: Interesting idea that shouldn't really need that much to get going.

If I understand correctly, I would add a loop pumping water from the hot side of my current water heater, through the plate exchanger, and back into the cold side of the water heater. I imagine I could use another Bosch electric water pump to move the water similar to the one I'm using now to move the Webasto heat through a loop going to pre-heat the bus engine.

Do I need to add a water temp sensor to shut off the Webasto once the water heater reaches proper temp? Otherwise wouldn't it just keep going till the overtemp shut down kicked in? I'm thinking that I could use a DPDT switch to re-route the thermostat in the coach to the water temp sensor for use in warm weather. I could get a NC sensor with a preset open temp around 130-150 degrees, which should cycle the burner as needed to keep hot water hot.

You're correct - it should not be difficult to add a few jumpers to keep the Webasto burning in warm weather, but I'll also probably need to add a manual fan shut off switch to keep it from blowing into the coach.

What size heat exchanger do you think would be needed?

Richard

[lvmci]

Tankless propane is the way to go, you can get them with a pilot light, electric powered by 2 D, cell batteries or 12volt, or 110ac...lvmci...

[Flight102C3]

I've been thinking about a EZ 101 tankless. Not sure about how to install. Two D cells to run. If there is a will there's a way!!

[Lee Bradley]

Another way to go is to add another small Webasto in a loop off your current water heater.  It will circulate and heat the water in the tank to about 180 degrees. If that is to hot add a tempering valve.

[TomC]

We have a bit bigger system. 2-10gal electric water heaters from HD. One feeds into the next with the final one wired through the inverter so we have hot water all day while driving, and hot water when we stop. I installed the two water heaters in 1994 and except for draining them once a year, have done absolutely nothing to them. And I know the anode is still working since the water stinks like sulfur when the bus has sat for several weeks. The two separate 10gal water heaters heat up in less than an hour from cold, shorter when warm. I don't think you could find a more dependable water heater than this-I like it so much, I'm repeating the 2 water heaters in my truck. Good Luck, TomC

[RJ]

Richard -

Our Angola Coach has an 11-gallon SeaLand marine water heater.  Internal heat exchanger is tied into the coach's cooling system that feeds the main coach HVAC, thus generating "free" heat while rolling down the road.  120vac electric element for heating when parked.

Simple and efficient.

We like it.

FWIW & HTH. . .