Thetford N150 cooling problem. (1 Viewer)

[franknjan]

Hi. We are currently in Spain and our thetford N150 ses fridge freezer has stopped working. There are no faults showing. Blue light on constant. I thought it was the thermistar initially. Couldn't get a spare locally, so paid for special delivery from the UK. Fitted it with no change. Damn.
I've found that when gas is selected the fridge is cool but not cold. I can hear the burner. I suspect the control board could be the next option.(I have replaced this before) tried the locally dealer again nil stock. He wants €250 and will have to order it. I'm not going to pay that, at least Dick Turpin wore a mask.
Does anyone have any experience of this problem. I don't mean being ripped off.
We've got a few more weeks before we go home, so some help would be appreciated.
Thanks Frank.

 

[SandraL]

The fridge liquid pipework is sealed, no valves to operate etc. The pcb controls the method of heat and the control of the heat.
So if you can get mains, disconnect the mains element from pcb and connect it direct to a fused 3amp mains supply.
It is probably best to pull the fuse supplying 12v to the fridge, not the heavy supply for the 12v element, the small supply for the pcb.
You can bypass all the controls and pcb.
If fridge now gets cold problem is not in liquid fridge circuit.

If this works you could do same for 12v.

Gas will be controlled by pcb so cannot easily be bypassed.

This should only be attempted if you are confident in working with electric.

 

[franknjan]

Thanks sandraL. Your tip was spot on.
Hadn't thought about bypassing circuit board with mains heater. Easy fix. Temp dropping like a stone now. Just have to remember to control the temperature manually till we get home. Cold wine and beer tonight to celebrate.

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[franknjan]

Things didn't quite go to plan. Although initially the temperature dropped it soon levelled off. Still not cold.
Today saw the complete removal of fridge, turned it upside down and back. Refitted. Connected back to standard. Switched on, and went to watch Wales beat Italy.
The freezer compartment is making ice although the fridge is not as cold as it should be.
We'll leave it overnight and see what tomorrow brings.
At least we're second in the six nations championship.

 

[franknjan]

Update.
It seems that everything is back to normal. All be it on gas only. (Cos I can hear the burner operating)
I think old trick of turning the fridge upside down still works a treat.
I'll leave the fridge running on gas until we get home. Then carry tests on 240v.
What I have noticed, while fault finding on site. Is the voltage in Spain, on our site anyway. Is only 225v. I wonder if this contributed to the problem ??
I'll keep you posted.
Frank

 

[Richard n Ann]

If you can't find a fault check the heat transfer compound on the back of the aluminium fins. Ours dried out and some of the symptoms sound like yours...

See here:
https://www.motorhomefun.co.uk/forum/threads/our-3-way-fridge-saga.160227/

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[franknjan]

Update. 10 days on.
The fridge has been working perfectly since my last post, all be it on gas only. Yesterday I switched it back to 240v and everything seems good.
When I get home I will check the alloy fins and compound as suggested by Richard and Ann.