Dometic fridge won't run on gas

[Tel7]

We have a 2010 Bailey Pegasus 554 with a Dometic RM 8550 fridge (according to the sticker behind the vege tray).

After much effort and help from several of you, I solved a problem with a stuck corroded igniter battery, thank you, and I was able to start and use the fridge successfully.

However, in our next visit to the caravan (now), I can't start it.

The gas is on at the tank and is getting to other appliances, (and to the fridge I expect, based on the flame starting sound - see below).
All 4 caravan gas isolator switches are on.
I turn the fridge mode to gas.
I push in the temperature (thermostat?) knob in and turn it at least 75% way around and hold it in.
I then press and hold the igniter button in, and I can hear it clicking several times a second. I promptly hear it light up.
I release the igniter button (at that time or even 5 secs later), but continue to hold the temperature knob in for 15 or even 30 secs.
The needle doesn't start moving towards the green, as it did in our last visit, but I don't know what's changed. I release the temperature knob, and try again, but alas, to no avail.

Anyone had this problem before?
Any suggestions?

Thanks.
Terry
NZland

 

[Jcloughie]

Possibly a blocked jet.

When working, you will hear the flame light.

John

 

[Tel7]

Thanks John,, but I already think I hear it light.

"I then press and hold the igniter button in, and I can hear it clicking several times a second. I promptly hear it light up."

It doesn't light up on every attempt though. If I leave it a while it seems to light again.

Still sound like a blocked jet? If so, how many jets are there and how to get to them and how to unblock them?

Thanks.
Terry

 

[Jcloughie]

Thanks John,, but I already think I hear it light.

"I then press and hold the igniter button in, and I can hear it clicking several times a second. I promptly hear it light up."

It doesn't light up on every attempt though. If I leave it a while it seems to light again.

Still sound like a blocked jet? If so, how many jets are there and how to get to them and how to unblock them?

Thanks.
Terry

There is only one jet. If it is lighting then that is most likely not your problem. If it is not staying lit, it might be the thermomcoupling. These are not expensive and fairly universal. But it may also be the gas control valve, which are expensive I think.

If changing any item it should be done by a gas safe engineer. But be aware, that you can often get spares online for a fraction of the price caravan dealers charge. Look on the components for identification.

John

 

[JTQ]

First I don't know your particular fridge but I know of generic problems many have.
One thing worth a try first, with a minimum of pulling it apart .

There might be an accumulation of flakes of rust over the burner, flakes that have tumbled down the tube directly over the burner. As these fridges age those that have a history of use on gas "suffer" this problem.

In most cases the burner shield is secured by a single screw that only needs slackening not removing to enable the shield to be removed.
Then with a length of plastic tube you can use this in your mouth as a blow pipe to give the burner a good puff of air to blow the rust dust flakes out of the way. Its on the burner they can be critical to a clean flame

The burner is a little tube the jet fires gas into, it has on top a row of slits, the gas air mix coming out of these slits feeds a flame. With the rust flakes the flame is distributed and so does not always properly heat up the gas failure device, so the gas gets switched off even though it initially lit.
Don't jump in and play with the jet too readily, based on what you have said.
It also could be in a really tiny disc and overly easy to get lost, plus to get there you are getting into gas engineering territory and really need to know a bit about what you are doing, here with regulatory implications.

 

[toad a caravan]

Tel7 have you a manual for the fridge,

 

[JTQ]

From page 32 LINK

This might give you more info LINK

I suspect your burner will be of that type rather than the tube, the rust issue is just the same and very evident in the clip. Try blowing either by mouth tube or better still a compressor fed gun, long before going into it as deeply as the presenter did.

 

[IanB1485]

The selector switch is faulty - had this on several fridges of similar models . A set of contacts on the selector switch , when set on gas carry the small electrical current (20mA) generated by the thermocouple , to the gas valve's internal solenoid keeping it open when the thermocouple is hot. The selector switch contacts are coated with a thin layer of dirt /oil increasing the resistance of the contacts preventing enough current from the thermocouple reaching the gas valves' internal solenoid. the switch can be cleaned , by carefully opening up the two halves of it. and physically cleaning the contacts with isopropyl alcohol( Or use switch cleaner spray , you may be able to inject it without opening up the switch) . Make sure the mains is disconnected from the van as the supply to mains heater on the fridge also passes through this switch. If you are not confident in taking the switch apart ( there are fiddly bits inside) then a new switch is available off the web priced between £44 to £75 dependant on supplier .

 

[ProfJohnL]

Tel7 was kind enough to indicate in his last line that he is in New Zealand. I do not know what the NZ regulations are regarding DIY repairs to gas appliances, You will have to check your local regulations to see what you are allowed to do in respect of gas work.

 

[Tel7]

Tel7 have you a manual for the fridge,

Yes, I have a link to some manuals online, thanks.