Dometic Fridge

I suspect we heading towards trouble with our fridge as over the last couple of days it takes rather a long time to ignite on gas, clicking and has also then gone out soon after and I have had to go through the ignition process again. Then it is fine.

Plenty of gas in tank, outside vents no covers on.

Reading about this it looks like maybe the burner needs cleaning. Is it easy to get at, or is it best left to a "real" expert?

Never been looked at etc since new in 2016.

Thanks for any advice in advance.
---------
Richard

My mobile engineer was able to remove burner through access via fridge vent.

Paulmold wrote:My mobile engineer was able to remove burner through access via fridge vent.

Thank you Paul for your quick reply

Yes I think I will give a mobile engineer a call as the Motorhome dealers just seem to want to do a damp check and I have found they don't want to get involved in any thing to do with gas. Also gas is not my area, electrics I am ok at, I think.

Just turned fridge on to gas at home as we are going to the beach and all is well, but will it last?

Cheers.
----------
Richard

How frequently are you lighting the fridge?

The symptoms you describe are exactly what happened when we had a small leak in the gas line between the isolating valve in the wardrobe and the fridge. It was a slightly loose compression joint, enough to lose the gas from that section of pipe when shut off but not enough to prevent the fridge from working once lit.

These are also the same symptoms we sometimes get after changing the gas bottle, so there can be a slug of air in the pipes when you first try to light the fridge. What I now do is run the cooker rings until they light, which makes sure the air is out of the system, then I light the fridge.

rogerblack wrote:How frequently are you lighting the fridge?

The symptoms you describe are exactly what happened when we had a small leak in the gas line between the isolating valve in the wardrobe and the fridge. It was a slightly loose compression joint, enough to lose the gas from that section of pipe when shut off but not enough to prevent the fridge from working once lit.

These are also the same symptoms we sometimes get after changing the gas bottle, so there can be a slug of air in the pipes when you first try to light the fridge. What I now do is run the cooker rings until they light, which makes sure the air is out of the system, then I light the fridge.

We tend to light the fridge a couple of times a week and it runs for 6-8 hrs.

I will check the joints to see if they are tight. As we have a underslung tank, I don't think air gets in, but good point about lighting a ring first, will give it a go.

Just back from a trip out today and I had to relight it a couple of times at first, then it behaved. My son managed the get the external vents off, so will take a look tomorrow.

Thank you for the advice.

Cheers,
---------
Richard

I cleaned the gas burner on the Thetford fridge in our van today.  It had been blown through with compressed air and the flue similarly cleaned last week but this did not resolve the problem of the fridge not working on gas. The symptoms were as you described, and the fridge would not cool when switched to gas mode. In my case the flame on the fridge burner had a yellow tip which is a sign of either contaminants in the gas (not unknown) or a dirty burner.

I was able to remove the burner without difficulty via the lower vent, by uncoupling one compression fitting and a couple of self tappers.  On removal I unscrewed the jet from the burner body and placed the jet in solvent cleaner for a couple of hours.  I let it dry overnight and blew it through this morning with canned compressed air.  I also blew air through the burner body and checked the 4 slots where the flame ignites were clean. With the burner back in the fridge and after a check for leaks on the compression fittings, ignition was much quicker than previously and the flame was clean and blue.  The fridge has been operating on gas all day and is now working properly once more.

I read somewhere on the web that burner cleaning is recommended twice a year if operating on tank (as opposed to bottled) LPG.

Tim

Kemerton-bath wrote:I cleaned the gas burner on the Thetford fridge in our van today.  It had been blown through with compressed air and the flue similarly cleaned last week but this did not resolve the problem of the fridge not working on gas. The symptoms were as you described, and the fridge would not cool when switched to gas mode. In my case the flame on the fridge burner had a yellow tip which is a sign of either contaminants in the gas (not unknown) or a dirty burner.

I was able to remove the burner without difficulty via the lower vent, by uncoupling one compression fitting and a couple of self tappers.  On removal I unscrewed the jet from the burner body and placed the jet in solvent cleaner for a couple of hours.  I let it dry overnight and blew it through this morning with canned compressed air.  I also blew air through the burner body and checked the 4 slots where the flame ignites were clean. With the burner back in the fridge and after a check for leaks on the compression fittings, ignition was much quicker than previously and the flame was clean and blue.  The fridge has been operating on gas all day and is now working properly once more.

I read somewhere on the web that burner cleaning is recommended twice a year if operating on tank (as opposed to bottled) LPG.

Tim

Thanks Tim, sounds like mine is overdue a clean at 4.5 years old!
Planning to do it tomorrow, results to follow.
Cheers,
---------
Richard

Update, I have blown the burner through with my airline, still would not light.

Ignition sparking, then stopped, then started again as I read it should do. Still no flame staying on.

So I managed to contact a mobile guy, most are fully booked till mid Oct. So made a booking with one being squeezed in 14th Sept. 

Blow and behold, just tried it and working ok! Only thing I did was to hold the reset button in for 10-20 secs, is that what is needed?

Nice blue flame, fridge cooling

Leaving it on overnight to see how it goes.

One chap said, new burner reqd at £150!  another said maybe jet blocked, so will do what Tim said and remove it and give it a good soak.

While on the subject, I noticed the white surrounds where the grills fit are all cracked around the fixing screws, AS over tightened? Not a problem as they hold the grills ok.

Dometic 8501 model fridge. Don't want to cancel and miss my slot, but will see in the morning, as planning a few nights on a CL end of month.
----------
Richard

Even if it behaves itself , let the mobile guy service it which should include cleaning the flue.

Richard,

That sounds positive, our fridge is a Thetford so can’t advise on what your Dometic reset button does.  

What struck me about the burner jet is how tiny the orifice is. I expected it to be similar in size to those in the burners on the gas hob, but it’s much smaller. Consequently it doesn’t take much to block it. 

Tim

Kemerton-bath wrote:Richard,

That sounds positive, our fridge is a Thetford so can’t advise on what your Dometic reset button does.  

What struck me about the burner jet is how tiny the orifice is. I expected it to be similar in size to those in the burners on the gas hob, but it’s much smaller. Consequently it doesn’t take much to block it. 

Tim

Yes I noticed the jet looks small, reminds me of the old paraffin blow lamps and primus stoves we had as kids.

Thanks Paul and Tim
----------
Richard

PS still running ok.

I forgot to say that our vent frames are cracked in exactly the way you describe yours Richard.  No loss of function so don’t plan to change them, especially as it’s not visible with the vent grills in place.

Tim

Kemerton-bath wrote:I forgot to say that our vent frames are cracked in exactly the way you describe yours Richard.  No loss of function so don’t plan to change them, especially as it’s not visible with the vent grills in place.

Tim

Thanks, I guess it might be the flexing of the van, etc.

Fridge still working on gas, just spoke to the mobile chap, very hard to find intermittent faults, sounds expensive.

As Paul advised might get it cleaned, might also take the jet out tomorrow when the wife is out

House central heating boiler £80 approx for a yearly service, leisure vehicle, the sky's the limit.

--------
Richard