I'm buying a short school bus and want to use engine heat for the water tank. Last post here is over 10 years old, quoted at bottom. I haven't decided if even gas or diesel, but likely will be a gas Ford 450 21 ft. Is it worth it and what is an easy way to reuse engine heat? I am also looking at putting a water tank next to tail exhaust, as lots of room down there for a big tank! But all that work gets expensive and don't feel it's worth it. Perhaps simply use solar panels (they now are so cheap), then I don't even have to drive. But TWO ways to heat is better than one. One user posted its great to arrive end of day with full tank of super hot water ... Yes sir I agree with that!! Here is from a 2009 RV.NET post...... Any idea how much this costs to install at an RV dealer?Quote:My only concern, comming from the automotive industry, would be letting the coach builder touch the engine coolant system. Too many variables (flow, volume, etc) to calculate, and a much longer run would put variables that I don't know if I would like.My 1990 Winnebago Warrior has the Motor Aid package also. This heats the hot water tank and provides cabin heat. The owner's manual says it also provides more heat-removing capacity for the engine. The thermostat should prevent it from ever over-cooling the engine.I'd think if they have been doing this for 20 years if there were problems they have hopefully been ironed out.Steve

I don’t follow , so you get to campground and have hot water but the next day you don’t. Is there a problem with the water heater? I would hate to have to fire up the engine for an hour to heat the water for a shower. I maybe missing something here.

I had a 2011 Winnebago with the Motor Aid Package. It warmed the water nicely, and it didn't appear to have an impact on the engine temperature.

This is not news. All of the GMC motorhomes ('73~'78) were built with this feature. It is a standard tank used in the marine trades. Yes, a day later it may be cold, but ours is still good for a morning shower.Matt

I'm trying to think of the Suburban water heater number SW6-DEM. I have this one on my Vogue. The WH itself is no problem to install but adding the additional hoses would be pricey! If you could mount that Suburban model near the MH engine then maybe but I'm thinking price prohibitive!

Recycling engine heat for hot water tank | Good Sam Community

Gjac
Explorer III
Jun 03, 2021
Free flow low back pressure muffler. I don't know what a newer bus would have in it for an engine so I would not worry about it until you know what it is, its weight and what kind of cooling system it has.
wildwind_creati
Explorer
Jun 03, 2021
I am still shopping for the bus .... Mine will be stripped without much installed. It likely will be 2008 +/_ a few years. It seems you get the most for your money around that year. It should be lighter than original. What is "FF" muffler?
Grit_dog
Navigator
Jun 03, 2021
The OP doesn’t own a bus. They are considering it.
Gjac
Explorer III
Jun 02, 2021
wildwind.creations wrote:
Please clarify, is there an added benefit to reduce eng temp and less cracked manifolds if I run a "temp" hose to the water heater? I can see how not worth costs just for hot water.
Big Block engines both Ford and Chevy generate a lot of heat especially in heavy MH's they are known to crack the cast metal exhaust manifolds. Headers, larger cooling capacity, air dams to force air through the radiator, all help to reduce the heat. I guessing a school bus conversion when complete will weight 15-18k lbs, that is a lot of weight to pull up a hill on a hot day. If your Eng is a mid 90's or older and a 460 or 454 block you will add about 80 more HP and equivalent torque by adding headers and a FF muffler. What engine do you have in the bus? What year is the chassis?
JaxDad
Explorer III
Jun 01, 2021
wildwind.creations wrote:
ALL FANTASTIC INFO HERE THANKS TO EVERYONE!

A 2008 short school bus is $8000 and seems built for long life. It seems an economical option? Perhaps used tires or parts could be found cheap? I had not considered costs of repairs.

One thing to consider if you haven't already pulled the trigger, most school buses (especially shorties) are designed for stop & go city driving, they aren't usually geared for highway driving.
wildwind_creati
Explorer
Jun 01, 2021
Please clarify, is there an added benefit to reduce eng temp and less cracked manifolds if I run a "temp" hose to the water heater? I can see how not worth costs just for hot water.
Grit_dog
Navigator
Jun 01, 2021
wildwind.creations wrote:
ALL FANTASTIC INFO HERE THANKS TO EVERYONE!

A 2008 short school bus is $8000 and seems built for long life. It seems an economical option? Perhaps used tires or parts could be found cheap? I had not considered costs of repairs.

Most of what mrandy wrote is correct. Although there are school bus conversions out there that range from basically a homeless shelter on wheels to nice full blown RV conversions.

Based on your post above, it doesn't appear that you are that "into" vehicles or handyman stuff to accomplish the latter with much efficiency or economic feasibility.

Cost of mechanical parts? Meh, same as any class 3-4 gas despite what mrandy cautioned. You need something relatively heavy duty to haul around a small mobile home.

Regarding the water heater specifically, the time and effort to install a heat exchanger seems like a waste of both. New 6 gal LP water heater is about $400 + hardware. The heat exchanger will only be useful for, what half a day after driving the vehicle I suppose if your driving every day, that is fine, or only showering and doing dishes on driving days. Otherwise, you're doing double the work and expense to have 2 separate water heaters, one of which is useless when parked.
Gjac
Explorer III
Jun 01, 2021
If it is just for hot water to me it is not worth it. If the bus has a 460 engine they tend to run hot and crack exhaust manifold's, adding a run of high temp hoses to the WH would reduce the engine temps. Have you driven the bus up a hill on a hot day yet? Does it have the 460 engine?
Veebyes
Explorer II
May 25, 2021
My 32' Albin boat had a two way water heater. Less than half hour from cold start engine the fresh hot water was a blistering 170 plus degrees. That heat carried overnight & into the next day no problem.

Our cruising habits meant that the genny was hardly ever started to provide 120VAC to heat the water.

A system like that would be great as a regular feature for class As. Yeah, I know, extra cost that nobody wants to pay for in plumbing & the two way heater.
time2roll
Nomad
May 25, 2021
As long as you are pulling radiator hose consider a second space heater on the return line. Or does a bus already have this to provide heat to the rear seats?

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