on demand hot water heater

[GMC5303Wonder]

I am thinking of putting a on demand hot water heater in my fishbowl.  Was wondering if anyone has had any success or advice or if this is even possible in a rv?  Currently I have a conventional 10 gallon propane style unit.

Thanks for any help/advice/recommendations!

Noah

[prevosman]

Power management is always a big concern on a coach. While an on demand HW heater has merits one potential issue I can see is if you are drawing power near the limits of the shore power or generator and the heating element kicks in because you need hot water you may be tripping breakers.

A conventional HW heater with a tank can be heated when energy is available and used even if the power to it is turned off. A second advantage of a conventional style HW tank is if it is equipped with coils for the circulation of engine coolant you are getting HW for free when the bus is running.

[GMC5303Wonder]

Although this is true...you can only get so much power through shore or generator power

I have seen models that will run on propane... rather than electricity..... I believe this would solve the shore power issue with tripping breakers but I am not sure.

Has anyone experimented with this on their Coach? 

Thanks

Noah

[bruceknee]

Use a Proheat and a flat plate heat exchanger, you will have unlimited hot water,almost instantly, your tank bay will stay warm, and you can heat your bus with hot water baseboard comfortably with outside temps to 10 degrees

[Melbo]

Typical residential water heaters use between  32 and 40 thousand btus to heat water the natural gas instant water heaters use 175 thousand so the demand though not constant is MUCH greater. Electric demand water heaters (depending on size) typically use two or three sets of 40 amp 220 breakers. Once again quite a demand on your electric.  I am not properly schooled on the fuel consumption for proheat webasto or other diesel powered heaters but I would think they would be more practical for hot water as well as engine preheat and keeping the bus warm inside if you are trying to avoid the water storage tank. As previously mentioned the storage tank stay hot for a LONG time so you can shower while on the road hours after you have turned the power to the water heater off AND you can use the engine (with proper plumbing) to heat the water in your tank while driving.

HTH

YMMV

Melbo

[Uglydog56]

I have this one on the way:

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&_trksid=p3984.m1423.l2649&item=250832949074&viewitem=&sspagename=STRK%3AMEWAX%3AIT

I am hooking it up to shower and washing machine only, with 6 gal suburban lpg/elec rv water heater for everything else.

I will let you know how it goes.

[GMC5303Wonder]

Uglydog.........
please let me know how that works for you! Im really interested in something similar!

[pickpaul]

Instead of a proheat, I plan to run a waste oil burner on veggie oil or waste motor oil eventually. Here's one that looks interesting. Struggling to find one smaller than 100,000BTU.

http://www.wasteoilboiler.net/catalog/item/2286321/3192712.htm

It seems silly to head to Florida to avoid high winter fuel bills when some quick energy dumpster diving is possible :-)

Cheers, Paul.

[GMC5303Wonder]

Paul....
awesome idea!  Ill have to do some looking into that possibility!
Im all about goin "green" as much as possible

[jack14r]

I have a titan that is plumbed to the shower only and is only wired to the generator,the unit will draw 38 amps on each leg of 240 volt,it is the answer for never running out of hot water.