Running a water heater off the inverter

[cody]

Our 1978 revcon has a LP water heater very much like the new atwoods but it has a heating coil from the engine that the loop goes thru the water tank and heats it while on the road so it can be warm when you stop, old technology that would work great today.

[luvrbus]

Cody, maybe old technology and a little pricey but Seaward still makes that hot water heater today I used one in my Eagle ,if doing a conversion today would use one again



good luck

[cody]

Clifford, I thought they were long out of production, I appreciate the lead cause I'd really like one for my iggle, right now I'm running my 20 gallon electric one thru my inverter, (yes illegally too lol)

[redbus]

I have been thinking about wrapping copper tubing around the water heater with engine coolant running through it. As you drive the engine heats the water heater. What do you think?

[garhawk]

In response to Cody's reference concerning the engine heated fluid flowing through a "loop" inside his Revcon's water heater, I'd be surprised if that is actually the case.  In GMC's Royale series motorhomes, there is only a small diameter aluminum tube (1/2" guess) welded to the outside wall of the propane fired, aluminum,  water heater tank.  It is only 'tacked' in a couple places with a rubber feeder hose attached to one end of the tube and, a return hose to the other end.

It is VERY effective and, without the risk of anti-freeze contaminating the water inside the tank should a rupture occur. 

Check it out Cody - bet you a beer Revcon did the same.

[cody]

Gary, thats probably how it works, I haven't looked that closely at it, it sure is a great idea for hot water while going down the road, the line continues to the front of the revcon and hits the heater up there.  I know it works great and it sure is nice to pull into a campground and have your hot water ready and waiting.

[boogiethecat]

Since the idea of fetching hot water heat from the engine with a heat exchanger has been brought up, I thought I'd chime in and say "yes it works very well".  I did this on my first bus with a 16" long "shell/tube" style heat exchanger and it worked fabulously.  It made the water too hot though, so I used what's known as a tempering valve to automatically mix the hot with cold to get a safe temperature in the actual hot water lines. Again, a perfect system, cheap, effecitve.
FWIW the next iteration of that system was to put the same sized heat exchanger in the heater lines of my Toyota pickup... with that I'd go to a mountain campground with 20-30 friends, hook up a water hose to a camp faucet, through my heat exchanger and off to  a shower head.  Man oh man was I the most popular guy in the camp- simply idling the truck gave unlimited yummy warm showers to everyone!!!! That system actually got used more than the one in the bus!
In either case as long as you use a high quality brass/copper exchanger either new or very good condition, and especially if you don't plan on using that water for drinking, I'd say a double loop is unnecessary.  It'd take a lot for an automotive system at it's fairly low pressure to break thru or otherwise damage an exchanger that's rated at hundreds of PSI.  Just my opinion though. And I never use the main tanks on my bus for drinking or cooking- only washing and showers.  I have a separate 20 gallon tank with it's own pump and separate spigot for drinking/cooking, & that gets filled with R/O water or Crystal geyser water only! Much healthier!!!
Ok, that's all fer now...
Boogie

[John Z]

I think wrapping the water tank with copper pipe might be overkill and not needed. You could just attach about 8" of pipe to the tank with JB weld or some such method. My Atwood water htr is exactly as garhawk describes. Simply a "U" shaped piece of aluminum pipe tacked to the tank. At first i thought there was no way that little loop could heat the water.