Posted: 7 April 2016 7:59 AM Subject: RE: Help trouble shooting Dometic fridge Plese
Welcome to the Out&AboutLive forums, Barry.
Yours is a very specific question that I’m doubtful any forum-member (unless they happen to be a Dometic engineer) will be able to answer.
Just in case someone here has had the same problem and can say how it was fixed, it might be helpful to know if the failure to cool adequately on gas suddenly began to happen or developed gradually.
cools properly on 12V and 230V suggests that the cooling system itself is OK, and that you get a flame (albeit a very small one) at the gas-burner indicates that the fridge’s gas ignition system is operative.
My last motorhome had a Dometic RM7605 fridge/freezer and, although I have no hands-on experience of your smaller-capacity fridge, I would expect your RM7631 model to function similarly. My RM7605 had no gas pilot-light, the gas-burner firing up and turning off according to the temperature within the appliance’s interior and the temperature chosen on the control knob. When the burner was lit the gas flame was substantial and could easily be heard whooshing. I don’t recall the burner being ‘throttled’ - the burner would just light, run at full-blast for a while and then switch off.
The burner-unit is a simple thing and should not be problematical in itself. If it’s just the small size of the gas flame that’s the culprit (ie.the fridge will otherwise light OK when gas-operation is selected) this suggests that there is something impeding the flow of gas to the burner - either within the gas-valve assembly or the gas-jet being partially blocked. (Have you tried replacing the jet, as that’s easy/cheap enough to do and the jet would be my prime suspect?)
(If I really wanted to know about the control-box wires’ voltage, I’d try to get the information from a friendly Dometic engineer.)
Posted: 7 April 2016 1:30 PM Subject: RE: Help trouble shooting Dometic fridge Plese
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Posts: 435 Location: Rojales Spain Knaus 650 MF
On the 7xxx series on the out let side of the gas valve there is a filter in the tube (bit like a cig filter) you can get it out with tweezers this may be mucky from bad gas chasing poor gas flow, You say you cant see any problem with the jet or the burner ..I assume you have therefore stripped it down ..the reason i ask I had a spider build a web in the burner and couldnt see it until it was stripped this was causing the burner to pop but wouldnt light not quite the same problem but if its partly blocked it could be the cause.
If the flame is ok then the chimney may be sooted up this will also cause the fridge not to cool as it should.
Hi Baz, do you really want to mess around with the Gas supply in what is a very small area. If any thing should go wrong like a gas leak then your insurance would be very reluctant to help you as I think that by law only a gas engineer should touch a gas system. Not trying to be a know it all just thinking would I like my family to take a chance that I had put every thing back correctly.
Posted: 23 April 2016 7:05 PM Subject: RE: Help trouble shooting Dometic fridge Plese
Location: Nottinghamshire
We did have a problem with our Dometic 7 series fridge however this was caused by broken contacts in the connector block that pushed onto the grey encapsulated ignition module. Dometic engineer quoted many pounds for a new wiring loom so i sourced the connector and replaced it for a couple of pounds. The effect of this was that the gas valve would operate and then shut off at random due to the varying resistance of the connection cutting off the supply, however i doubt this would be your issue as a low flame does indicate some gas getting to the jet. So either the gas pressure is low or the jet is blocked, the jets are available for about £10 and the hole is so small even a small bit of contamination will alter the flame intensity. Only competent people should work on gas so if you are unsure i would entrust the repair to a Dometic engineer.
