# Dometic Fridge Problems



## grouch (Oct 1, 2005)

We have a 4 year old Dometic RM641 Refrigerator. The problem is the burner lights up instantly but when you take your finger off the button it cuts out and resumes clicking. Eventually about one time out of twenty it will stay lit. Measures taken so far - a new thermocouple fitted (flame failure device),new jet, flue tube and burner cleaned. Dometic have no help line which in the fridge of this price is disgusting. No professional outfit can fit us in until May and we want to use the van for Peterborough. Any ideas please?


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## 97993 (Mar 5, 2006)

Having already tried all the obvious cures the only suggestion I have is weak mixture ie air leak or air in system 
check all conections also correct alignment of flame failure device in flame
Geo
ps If this fails expert help at hand from Monday/Tuesday Ie wife Pam works @ West Notts Collage Gas assessment centre the place is full of gas fitters and trainers and will run symptoms by them


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## grouch (Oct 1, 2005)

Thanks Geo.

Have checked for gas leaks etc. All appears OK. The flame failure appears to only fit in so far as it has a ridge which locates at the base of the burner alongside the ignition device. 

Any information your wife can glean would be much appreciated.


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## gaspode (May 9, 2005)

I know that this sounds obvious, but are you running on butane? If you are, the temperatures have been low enough recently to reduce the evaporation rate. Try warming the bottle in the house for an hour or two then try the fridge again.


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## MOTORHOMER (May 9, 2005)

Hi


That sounds like a problem we had from new on our Timberland. In the end I got Dometic out to have a look at it. I presume it is ok on electric & 12volt. 

This is a known problem with many dometic fridges & all that was needed was a plastc spacer behind the push button. No problem since. Timberland initially put a piece of cardboard behind the knob which worked initially but as it flattened then the problem came back.


Motorhomer


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## Drew (May 30, 2005)

Hi Grouch,

When you push the button in to light the fridge, you are actually opening the gas valve and allowing the gas through. The gas should automatically light when you do this, heat the thermocouple, which in turn keeps the gas valve open. Hence the reason for you keeping the knob pressed for about 20 seconds or so, as this allows the gas to flow until the thermocouple heats up and takes over.

If your fridge will not light, then it must be one of three things. Either the ignition system is faulty, or there is a lack of gas, or the thermocouple is faulty.

Have you checked the "spark"? Is the system lighting when you press the knob, and keep it pressed? if so then the ignition is O.K. When you remove your finger from the knob, does the gas go out? If it does, then it could be that the thermocouple is duff. If the system will not light when you press the knob, then there may be a gas blockage.

All in all, you must check that the igniter is working, and that you have gas at the thermocouple.

I hope that this makes sense


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## grouch (Oct 1, 2005)

Thanks to everyone so far. 

The thermocouple has been renewed. There is gas coming through on the valve and the ignitor fires the gas everytime and we are using propane.

The tip regarding the spacer in the knob I have heard about before but to test this, we have removed the knob and are pushing the spindle directly. Sometimes it works, sometimes it does not, when you release it very gradually. 

I have tried to check the power going into the valve but my equipment can detect none althogh obviously on the times it stays alight it must be working. Can only assume that the power going in is too small for my equipment to register.

Any more thoughts would be gratefully received.


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## Scotjimland (May 23, 2005)

Hi 
You have fitted a new thermocouple and checked it's in the hot part of the flame then the problem could be a dirty or poor electrical connection on the gas valve where the thermocouple screws in, unscrew the connection and give both surfaces a light rub with fine emery cloth, make sure the connection is tight when you replace it, failing that it could be the gas valve that's faulty.


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## vicdicdoc (May 14, 2005)

I was going to suggest the same as Jim, check that the thermocouple is in the hottest part of the flame.


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## MOTORHOMER (May 9, 2005)

grouch said:


> Thanks to everyone so far.
> 
> The tip regarding the spacer in the knob I have heard about before but to test this, we have removed the knob and are pushing the spindle directly. Sometimes it works, sometimes it does not, when you release it very gradually.
> 
> .


Hiagain.

Thats exactly how ours was. Atthe Shepton show january last year no hook up the damn thing wouldnt stay lit all weekend. Tried again the morning of departure hey presto it worked. Got home tried again. No luck.

Not had a problem since having the correct spacer fitted. This was done under warranty & dometic do know there is a problem with these.

Motorhomer


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## 97993 (Mar 5, 2006)

Pams had a word with the boffins at collage and from what they have been told all the bases have been touched on, the prime candidate apears to be the gas valve it's self, sticking diaphram. 
Or the only item not coverd so far if indeed you have one, is a secondary flame failure device sometimes fitted, to monitor the flame and bring in the igniton automaticly if gas blows out and often causes these symptoms if the cable from it to gas valve gets kinked and breaks down inside the insulation
if non of that helps were all as stumped as you :roll: 
Geo


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## hymerbug (Jan 10, 2006)

hi Grouch, know of someone who had a simalar problem you describe and went down the same route to try and cure the problem and from memory he found corrsion where the gas supply connected to the back of the fridge, he de - rusted it and cleaned the pipe work and said it worked after that, may be worth checking .

Colin.


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## grouch (Oct 1, 2005)

Thanks again to everyone for their comments. :idea: 

Having replaced the thermocouple unnecessarily and checked the electromagnetic valve we have come to the conclusion that the fridge will light first time every time provided the button is held in for approximately 2 minutes after ignition! Whether this is because of excessive length of the thermocouple we do not know. We have, however, sourced a supplier of the electromagnetic valve only at Orkli 0208 9741120 or on their website thereby avoiding having to buy the entire valve with electrical and thermostatic assembly which costs approximately £70.00 (another British rip-off).

We shall road test this at Peterborough next weekend.

Again thanks for all your help.


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## 97993 (Mar 5, 2006)

Not wishing to throw a spanner in the works but you would not be the first to buy a brand new faulty thermocouple
Geo


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## Snelly (Aug 20, 2005)

MOTORHOMER said:


> Hi
> 
> That sounds like a problem we had from new on our Timberland. In the end I got Dometic out to have a look at it. I presume it is ok on electric & 12volt.
> 
> ...


SNAP! We had exactly the same problem... the knob wouldn't push in enough to open the gas valve, but would set the sparker off... solved with a bit of chewed up paper!


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