Gas Valve Solenoid on Dometic RM 763 Fridge

[jrloucks]

I smelled propane and went hunting armed with a trusty spray bottle filled with soapy water. I found a leak on the housing of the propane/gas valve/solenoid in the rear of the fridge (Dometic RM 763).



I believe this is the original valve for this fridge based on what I've read. I also assume the valve is obsolete because of (more recent) Dometic field service articles referring to a "new" Weber gas valve.

Can someone confirm that the original valve is unserviceable?

I see a kit available on clearance from Camping World which includes: Gas Valve/Solenoid. Circuit Board. Thermocouple. Bracket. Installation Instructions. Ground Terminal



I already have a relatively new fridge controller card from Dinosaur Electronics (MICRO P-1338 REV 5) which supports the Weber valve. I can make a bracket for the new valve. So my preference is to purchase the Weber valve only.

If you've tackled this specific 'upgrade/repair' I'd love to hear from you.

[dougrainer]

TallyFeli wrote:
Hi....The 'thermocouple' or Igniter/identifier on most RV fridges doesn't control the gas supply as you recommend. It is wired to the control board which, thus supplies the voltage to worked the gas solenoid. Since it is essentially a mechanical gadget inside, it very well may be caught in the vacant position permitting gas to stream constantly. Give tapping a shot it with the plastic handle of a screw driver and check whether that fixes the issue. Provided that this is true, change the valve.

Well, you are wrong. The Thermo device DOES control the gas supply. It detects FLAME and if NO FLAME shuts off power to the Gas valve. Now, a seeping Refer gas valve is an extremely rare occurance. In 42 years as a RV tech, I may have seen 1. Now, Some Dometic refers have a Control board and ALSO an Ignitor module. 2 separate components. On these models the Ignitor module sends the spark and also sends the 12 volts to the Gas Valve. No Flame, no power to the gas valve. Doug

[TallyFeli]

Hi....The 'thermocouple' or Igniter/identifier on most RV fridges doesn't control the gas supply as you recommend. It is wired to the control board which, thus supplies the voltage to worked the gas solenoid. Since it is essentially a mechanical gadget inside, it very well may be caught in the vacant position permitting gas to stream constantly. Give tapping a shot it with the plastic handle of a screw driver and check whether that fixes the issue. Provided that this is true, change the valve.

[TravelinDog]

Thanks for the detailed write-up.

[jrloucks]

So final update on this project.

The burner valve assembly arrived. First thing I did was confirm/check the manufacturer stamp/silkscreen on the solenoid was what I needed. Photo below confirms a 12VDC 0.5PSI solenoid/valve.



Next I checked the burner nozzle size on the new valve and as per next photo it was a "58" vs the "53" on the original nozzle.



Next photo shows the 4 position plug on the new burner power wiring.



Here's a photo of P8 on the Dinosaur board where the 12vdc power comes from to open/close the new valve solenoid.



Next photo is a test fit of the new burner plug on the Dinosaur board. It fits, but one of the wires needs to move.



In order to remove the yellow wire from the plug, I cut the plastic surrounding the pin so I could extract the pin (I didn't have a proper wire extraction tool). Then I inserted the yellow wire into the proper location. The solenoid operates the same regardless of the +/- orientation of the 12vdc power. (I confirmed this with a bench test some time ago.)



Next photo shows the modified plug installed on P8 of the Dinosaur board and the jumper cut as required.



Next photo shows the new valve installed on the original burner metalwork. I had to rotate the new burner to fit under the refrigerant pipe. But I can still access the brass shutoff knob here. I was using soapy water to check the valve for leaks. Also, I replaced the "58" nozzle with the "53" from the original valve. I also double-checked the (air) space between the end of the new valve/nozzle and the burner orifice was the same as the original.



Success! Next photo shows the burner lit/operating with the new valve.



I un-plugged/plugged the 120VAC power cord from the fridge several times to make sure the propane was shut off/on as expected.

[jrloucks]

An update. The new valve/solenoid arrived. Unfortunately, when I compared the original valve to the new one, I discovered that the original nozzle jet (53) won't fit on the new valve. See photo.


Click For Full-Size Image.

I plan to return the new valve and I have ordered the DOMETIC 3850730569 RV REFRIGERATOR GAS VALVE ASSEMBLY 2007419217. This assembly comes with a new valve with a "58" nozzle. So, I'm hoping the original "53" nozzle will fit. It also comes with the premade cable where the male plug should mate with the Dino board's female connector.

[jrloucks]

So I ordered this valve solenoid manufactured by CEME. Norcold uses it for their RV fridges.

Norcold 633726 Gas Solenoid Valve, $60 on amazon

The solenoid itself has the same electrical characteristics required: 12VDC normally closed. And the valve has the same propane specs: 0.5 PSI and male fittings. I'm expecting the valve to be a little shorter in length, but that shouldn't create too much of installation challenge.

[jrloucks]

Got my reply from Dometic:

"Unfortunately we cannot recommend using new parts on your older model, we also can not order a replacement solenoid any longer. If you are experiencing a gas leak you may want to consider upgrading to a newer fridge. The newest replacement model for your fridge is DM2672 https://www.dometic.com/en-ca/ca/products/food-and-beverage/refrigerators/rv-refrigerators/dometic-dm-2672-_-183082. You can follow this link to view this product and to find a dealer near you."

Thanks but I'll look for another more cost-effective solution.

[jrloucks]

dougrainer. Thanks for explaining the differences between the two valves.

The instructions I received with the Dino Micro P-1338 Rev 5 board (which I installed a while back) has images of the two gas valves that this board supports. Snip-it below.



Once I hear back from Dometic to confirm the valve p/n to use for the RM 763, then I will reach out to Dino for confirmation. In fact, I may just ask Dino anyway, they should know p/ns and such.

Looks like the P-1338 board doesn't need/use the thermocouple.

[dougrainer]

Odds are from your pics, the newer valve is a ELECTRODE sensor type flame sensor which plugs into the control module. YOUR existing Gas valve has a older type THERMOCOUPLER connection to tell the gas valve to stay OPEN. So, just the Gas valve by itself will not work. You need to ask Dino if the pictured Board and gas valve will update to a Electrode based Flame sensor. Doug

[jrloucks]

With more digging I found what appears to be the p/n for the later model (Weber) gas solenoid: 2932615012, but have to confirm that this part is compatible with the Dometic RM 763 fridge. (New $130, Used $75).



There also is a Dometic Refrigerator Gas Valve Burner Assembly, p/n 3850730569, which may be compatible with the RM 763. (New $85)



I submitted my questions to Dometic to see what their response is.

[dougrainer]

Gas valves are NOT servicable. They are a replacement if defective or leak. Now, a individual may be able to find parts and rebuild, but any shop or technician would be a fool to rebuild a LP component that is NOT servicable. I would NEVER trust a rebuilt gas valve or allow my friends/family to be in an RV with one. Doug