Electrolux RM4213s Fridge on Gas

[pilchard]

This has got me thinking about how the thermostat works when on gas. (My Thetford fridge does not need any form of power when operating on gas, so it has to be purely mechanical. It has a manual piezo ignition.).

The pilot flame obviously has to stay on permanently. When the fridge has cooled to the chosen temperature you can clearly hear the thermostat operating (with a 'clank'). When the thermostat cuts back in you can hear the increased 'roar' of the flame if outside and it is quiet.

As far as I know, there is only one burner, so the gas supply must increase/decrease. (I am pretty sure it is just 2 states, rather than fully modulated). A follow-on to this is that a fault in the gas thermostat could mean that the flame is only ever in the maintain-small-pilot-flame state?

(In contrast, my portable 3-way camping fridge has no gas thermostat, and the gas flame simply remains constant).

I strongly suspect that the gas thermostat on my fridge is nothing more technical than a simple flow regulator with no capacity to sense heat or cold.

 

[Gafferbill]

As an aside, the jet should never ever be "cleaned" using anything like copper wire, dental floss or anything else, it should be replaced with a new jet, and depending on condition ( a lot of rust), a new burner .

Damian is of course correct........but during a trip to Italy with an obsolete refrigerator and probably restricted tools :huh:

My advice to use a strand of copper wire from electrical cable was based on practical experience and the knowledge that the technique has a high success rate.
The jet is made of a much harder metal than the copper wire found in electrical cable so there is a virtually nil chance of damaging the jet.
Dental products are a total red herring!
.

The injector hole for fridge is minute as it only passes about 125W of gas. I would be surprized if the smallest dental flosser is small enough to pass through the injector. A strand of copper from a fexible cord is going to be nearer the mark, and being copper should not damage the bore of the injector.

.......................agreed

 

[Dustydog]

Soaking in vinegar will also help the cleaning process.

 

[pilchard]

I think Damian's enthusiastic professional gas safety approach, re his advice in replacing not cleaning the jet, can be excused in this instance. I've written a lot on this thread and my mention that I'm in Italy is probably buried too deep to flag up on just a cursory read through.
I've contacted the Dometic dealer for the area and they can't/will not help on any level. It's too old for them to bother stocking spares. Maybe that's becoming the case in the UK? So if I want the fridge working on gas, it's a case of needs must when the devil drives. Of course, if you read in the media in the ensuing weeks of a Brit couple found dead in their camper van in Italy... you'll be wondering if Damian's advice may have been prophetic.
The copper strand will do in this instance, that's of course if the jet is blocked.
Today just may be the day. We've found a quietish (and legal) spot, we've just had lunch, a brew is on the way, ten minutes or so on the web (via our fantastic little Huawei Mobile Hot Spot, courtesy of 3 Mobile) and then I think I'll get cracking. Stay tuned to this channel for cries of help.

 

[pilchard]

So, three hours later and the fridge is reinstalled and running. How well it's running, we'll have to see.

I could kick myself for not cleaning the back of the ridiculous flame viewport because the large blobs of condensation on the window not only obscure, but have a lense effect.... distorting the size of the flame. Whether that's to make it look smaller or larger, I can't work it out. Anyway... the flame looks a bit larger than before.

Everything was in surprisingly good nick, with no rust, no soot, no burnt-out bits, and no blocked feed pipe. It was just the jet. It had the most miniscule of holes which could only be seen by shining a powerfull LED torch through it. The copper wire strand, carefully selected for gauge, and carefully proddled to instantly remove whatever was restricting it, did the job admirably.
My only error was forgetting to switch off the 12volt system before starting and blew the 15amp habitation fuse, but have plenty of spares.
The best part was the superb and invaluable assistance given... tool passing, torch shining, tea making, photo taking, clever suggestions giving... what a team!

Though the jet has been restored to it's original apperture size, I was unable to determine if there was a problem with either the burner or the flow regulator... because I didn't bench test it in the end. Finding the jet blocked seemed to determin the cause of the lack of performance. So we'll just have to wait and see.

 

[VicMallows]

A good day's work! We all await the final verdict.

 

[pilchard]

Well, we went for a walk... lovely easy valley bottom cycling round here, wish we'd bought some bikes with us... and we returned after about an hour.... today has turned into a clear blue sky scorcher and the views... oh the views are to die for... the van had not burst into flames... and.... guess what? The fridge has got distinctly cool! Nothing mindblowing, but it's only been an hour and it's a hot and sunny evening.
We'd promised ourselves a meal out to celebrate if the repair was a success so, if when we get back, or even better.... tomorrow morning... it freezing our tins of beer... then I'll rate it a success and send some snaps. Amongst the fridge snaps there might be the odd Dolomite view... but, there you go.

What a great forum this is! Should have joined yonks ago. Maybe I did and just forgot. But the superb (& respectful) help I've had here puts all those others in the shade.
Is this place pretty much a caravanners hang out, or are there camper & motorhome people here. I've had both in the past so not a snob about it.
Time to eat.

 

[Dustydog]

Well done Pilchard. Worth the effort. There are some very good diyers on here who have caravanned for years. There is a fine dividing line between diy and getting professional help. The truth is ‘ needs must” and we all do the diys suggested.
Very pleased it’s sorted.
As a matter of interest , on the grill for example the oem is a smaller jet diameter. There is an option on replacement for a slightly larger diameter jet which gives a better flame. Food for thought

 

[pilchard]

Dusty... why are we talking about grills? My missus, Liz, sez our grill and oven, are excellent. She made home made pizza in it a couple of nights back... made dough and rolled it out with a wine bottle on the table. She's nuts! Why would we want to turbocharge our grill? It ain't broke.
Now, if we could fit a larger jet to the fridge we could get it wacking out some serious sub zero temps, leave it's door open and use it as an air conditioner. Would that work?
Anyway... now fridge jet unblocked I'm now worried about excessive gas consumption. Everything has a downside.

 

[Hutch]

Agree with Dusty Dog, have a good trip and hope your beers, are cold for tomorrow.
Hutch.

 

[pilchard]

Final verdict... Total success. Fridge was arctic this am and we might have to turn it down a bit.
Because the help here has been so superb, you'll be getting more of this from me. The next will be ... why does my blown air gas heater moo like some ghostly grief stricken cow? Another thread I think.

 

[camel]

Pilchard, I know now it is late in the day but a can of Compressed air could of helped with cleaning the gas jets, I have just seen one on a search and it says on the can suitable for gas jets,

 

[pilchard]

Hi camel. If I'd had one, I would have used it. But the big deal on this job was taking the fridge out... cos you never know what can of worms you are opening... and it needed removing to open the gas line to the jet even if just to use a pressurised can. But there was one moment when I thought the compression back-nut to the burner (which holds the little cap jet in place) was going to shear. But a little WD40, a 2 minute wait, a few degrees of tightening rotation first, and then it came apart. No, the trepidation was worse than the work.

 

[Anseo]

Nice feeling eh!.

Very well done, enjoy a cool fridge and enjoying job satisfaction (it's allowed- nice one B) .)