Dou Therm 90120 Heater

Brian Long · 08-24-2010, 06:28 PM

The center heater in my coach operates but is not shutting the gas off when it shuts off. Anyone have any functional heaters they would like to sell or know of a source for a replacement gas valve?

prairieschooner · 08-25-2010, 03:28 AM

this could be a circuit board issue, can you scan the schematic?
Steve

prairieschooner · 08-25-2010, 05:31 PM

Brian,
I have Suburban heaters so cannot be much help with the circuit and my manuals are aboard the coach.
My owner's manual has a trouble shooting guide at the rear of the manual. It describes this potential problem and how to identify the problem. The first thing that I would do is identify the voltage (mine are 12 Volts DC), then you could use a volt meter to check the voltage at the gas valve. If the voltage does drop then the valve should be the culprit. My manual also describes cleaning the gas valve, I believe it was to blow it out with air to ensure that the orifices were clean.
I was able to find parts on ebay after getting the current part numbers.

Brian Long · 08-25-2010, 10:06 PM

Steve,
Thanks for your reply. I have pretty much determined the gas valve is faulty and confirmed this with Dinosaur Electronics who make a replacement ignitor board for my heater. What I need is a parts book or a part number for the valve which I have been unable to find at this point. I thought there was a reference in the archives for a shop that was familiar with these heaters but can't find it.

prairieschooner · 08-26-2010, 12:58 AM

I just did a Google search and found this link, maybe these guys can help;
http://www.rvpartscenter.com/prodsel...DID=87&CID=526

You will need your model and serial numbers so that they can look up the parts. I found a couple of great shops but they are in Arizona. You may be able to find someone in your area that used to service these units. Try some of the independents they usually save parts and manuals longer than the larger shops.

as a side note, I installed a Dinosaur Circuit Board last year and can highly recommend their product. My Heater runs better and quieter since the install. You'll have to wait

encantotom · 08-26-2010, 06:36 AM

hi,

if you do a search on this site for "furnace" and encantotom as the poster you will find my overview of rebuilding this exact same furnace as well as a link to the manual for the furnace.

i put in the dinosaur board and then rewired the furnace as well per the dinosaur instructions. they work great.

tom

encantotom · 08-26-2010, 06:42 AM

go here to look at parts and part numbers

tom

http://www.rvdealership.com/rvdstore...rNumber=885555

put furnace in search

then you can get down to duotherm

and the 90120 is called out specifically with parts, prices, pictures etc

prairieschooner · 08-26-2010, 12:33 PM

Here is the link to Tom's work;
http://www.newellclassic.com/forum/s...hlight=furnace

Brad Townsend · 10-24-2010, 10:17 AM

I have the same problem as Brian. It is not the board, most likely the gas valve. I have searched the web extensively plus Craigs list and nothing.
There must be someone out there that has an old duotherm 900 series laying around they could sell or part out. Seems like the problem may be in the electro magnetic coils but not sure but am pretty sure it is in the gas valve unit. Frustrating!!

prairieschooner · 10-24-2010, 02:33 PM

Brad,
Does it look like this one?; http://www.rvpartscenter.com/Product...DID=87&CID=526

I found HILCO RV (near downtown) to have "old stock", I always had to wait for them to call back so that they could look for the parts.

Brad Townsend · 10-24-2010, 10:36 PM

Hey Steve, That may be the one. How did you find it? I tried searching there site and only come up with a motor. To be sure I will have to take the heater out again and compare.
I have tried Hilco before and nothing but they may have found one since then. If need be I will check with them when I get down there.

Thanks Steve.

Brad

jwe648 · 10-24-2010, 11:46 PM

eBay has that part # Valve...

http://shop.ebay.com/items/duo%20the...?_dmd=2&_sop=1

Jimmy

prairieschooner · 10-25-2010, 12:56 AM

Brad,
When you get there you can try Al's RV in the Foothills (next to Fry's on Fortuna). I found those guys to be very good about getting hard to find parts. The other place is Spanky's in Parker, AZ. Between Al's & Spanky's, these guy are so good that I try not to get any parts until I can see them.

Brad Townsend · 10-25-2010, 10:39 PM

Steve

Do you have a number for Spankys? Could save a trip.

Thanks you guys for your time. This is a great site, sure wish there was a donate button.

Brad

prairieschooner · 10-26-2010, 01:47 AM

Spanky's RV, 1012 Joshua Ave, Parker, AZ 928-669-1600. They were able to order the parts hat I needed to repair my Suburban Furnaces when others couldn't.
Here is a link to their website; http://www.spankysrv.com/

Don't forget about Al's RV, they were also able to help with hard to find parts. See you guys in Yuma.

Brad Townsend · 10-26-2010, 10:25 AM

Thanks Steve.
Spankys looks like a good place to visit. They also have Camco sewer hose which I would like to get. Probably the most rugged hose out there. Bought the red hose a few years ago and now it has a bunch of pin holes which can make for a messy time. I have a small length of grey (Camco?) hose that came with the coach and I can stand on it and it won't collapse.

Brad

prairieschooner · 10-26-2010, 02:20 PM

Looks like Al's RV in Yuma also has the CAMCO Hose. They would be closer unless you will be going through Havasu/Parker on your way to Senator's Wash.

Brad Townsend · 10-26-2010, 06:06 PM

Thanks Steve
May go through Quartzsite if so then we could take the jeep to Parker, depends what I find out in the meantime.

prairieschooner · 10-27-2010, 02:00 AM

We had a great time in Quartzsite last year while staying at Parker and you're right just a short jaunt.
See you in Yuma, looks like we may have an impromptu Ralley so don't dilly daley

Brad Townsend · 10-27-2010, 01:08 PM

How about a chili cook off or something to that effect!