Water heater is toast

[POPPASMURF]

I tried our 98 Luxor out a couple of weeks ago and had problem running water heater on propane-wouldn't light. I polished the flame sensor but no help. Thought I would look into it today today. Did all the usual gas servicing- the manifold pressure is right on, flame sensor signal right on- thought I'd take the top vent sheet metal off to see if critters were nesting-strange sight-it looks like jolly green giant pinched the combustion tube shut- never seen any thing like it. Being as this heater is 1998 I think I;ll spring for all new. With a quick look I hope there is a panel at the back of the heater under the coach to disconnect water else I'm stymied before I start. Also my heater model indicates it to have an engine heat exchanger. Any one that can offer some insight on how to attack this thing is welcome. I have the electric bypass switch for winterizing but we'll see how well that can be trusted. I really hope the engine is not actually connected as chances are I'll be dumping antifreeze as well. HELP

[DAN L]

Originally Posted by POPPASMURF

I tried our 98 Luxor out a couple of weeks ago and had problem running water heater on propane-wouldn't light. I polished the flame sensor but no help. Thought I would look into it today today. Did all the usual gas servicing- the manifold pressure is right on, flame sensor signal right on- thought I'd take the top vent sheet metal off to see if critters were nesting-strange sight-it looks like jolly green giant pinched the combustion tube shut- never seen any thing like it. Being as this heater is 1998 I think I;ll spring for all new. With a quick look I hope there is a panel at the back of the heater under the coach to disconnect water else I'm stymied before I start. Also my heater model indicates it to have an engine heat exchanger. Any one that can offer some insight on how to attack this thing is welcome. I have the electric bypass switch for winterizing but we'll see how well that can be trusted. I really hope the engine is not actually connected as chances are I'll be dumping antifreeze as well. HELP

what kinda heater is it? atwood? suburban? 6 or 10 gallon? if i knew which you have, i could post some troubleshooting info.
can you light the burner with a barbeque lighter?
if you have an atwood, after doing the checks you have already done, imho the next thing for you to check is the plastic covered fuse on the lower part of the outside panel. you can remove it and check it for continuity or just jumper it out of the system for troubleshooting purposes. the purpose of this fuse is to ''blow'' if there is enough blowback heat from the burner to avoid a possible fire.
the engine assist water heater is a short piece of piping connected to the back of the water heater. on my moho, it is connected to the engine with 5/8'' rubber heater hose.
you will loose some coolant if you disconnect the lines.
it acts to transfer engine coolant heat to the back of the hot water tank.
on my moho, it keeps the water warm quite well while we are under way.

[John Hilley]

If the tank is good, all the parts necessary for repair should be available.

[POPPASMURF]

Yes, I know the parts should be available, but they are not. No one seems to be able to find a tank with a heat exchanger, there is only a couple of new old stock new units (with heat x). Being as this thing is 1998-sure a shootin the gas valve or some other disaster awaits. To remove that potential I'm springing for a new unit. My local RV repair (small town) has quoted me a price of $900 plus and hour install. I got prices from the city of 1150 to 1500 to supply only the tank. Being as I just got a pace maker installed I'm a little tender to climb under-in-and around so I'll settle for this. I've worked on my various RV's over the years but this one looks nasty to find all the connections. When I had an old Prowler 5th, the tank was less than an hour in/out. To tell you the truth-I didn't know I had a heat exchanger until I researched the model number. I will no longer run the tank up the day before we go any where now- I'll let the engine heat it up on the way.

[John Hilley]

The water heater is only $439 with heat exchanger

Atwood 6 gallon water heater with heat exchanger

Should take at the most only two hours of labor

The 10 gallon unit is $594.89

Atwood 10 gallon water heater with heat exchanger

[Mr_D]

Originally Posted by DAN L

on my moho, it keeps the water warm quite well while we are under way.

It should be HOT!! The coolant being circulated is probably 180°or higher depending on your engine coolant temp. Normal water heater setting is much cooler. When I first stop you have to be careful with the hot water, it's almost steaming as it comes out of the tap

[POPPASMURF]

Yes, I guess a bit of info would have helped me get help. It is an Atwood GCH10A-3E. Which deciphered means it is a 10 gal, propane/electric/electronic ignition & with engine heat x. Yeh like I said I did trouble shoot the electronic ignition but in fact the main burner would not stay lit because the upper end of the combustion chamber tube was pinched shut. I've never seen anything like it-& it didn't leak. We've run it on electric the last 3 weeks as we are living out of it while we are renovating the kitchen/living room of the house. It goes in on Monday to the local RV independent mechanic for replacement- then we are good to go for the summer. Wow-house will be done, motor home hummin- I'm looking forward to it.

[steveb05]

I'm having a similar problem with the Atwood water heater on my 2000 Itasca. The burner lights but shuts down after about 2 minutes. The overheat diode is intact I have 12 volts on both sides of the diode. is there a trouble shooing guide out for the Atwood water heaters Steve

[John Hilley]

Atwood Water Heater Trouble Shooting

Atwood Water Heater Service Manual

[Clay L]

One thing that bothers me - how could the tube have been pinched shut?

Could you post a picture?