Carel easy thermostat

[stender]

Anyone have any experience with a Carel easy thermostat for a fridge? http://alfaco.hu/file/CarelENG/PJEZ.pdf
I moved into a new house which has a corner fridge which is basically a corner cupboard with one of these thermostats and cooler.
It's recently risen in temperature and showing 9 on it. I found the above user manual which says to set the running temp, press set for 1 second then adjust the temp, and press set again for 1 sec. I pressed set for 1 sec, 5.0 appeared. I reduced to 4.0, pressed set but it still displays 9. Tried a few times and turning it off/on but no joy. The corner fridge company its from dont respond and an engineer wants £150 to come out. The thing is quite noisy so would replace it but it means replastering and new kitchen.

 

[Nozzle]

I suggest to you it is the fridge that is knackered, not your understanding of how the thermostat works

Nozzle

 

[stender]

Reluctant to write off a £3k fridge that easy

 

[ericmark]

The STC-1000 and the like be it a MH1210A or other number, all basic same design are the main stay of beer brewers and reptile keepers for many years. They cost between £6 and £20 depending where you buy from, and some have twin relays and some single. But most have a timer when used to cool, idea is if there is pressure in the pipes, there needs to be a time for this to dissipate before it tries to start the compressor motor. So you can set "slewing range of temperature" which is difference between off/on and a few other limits, however once it turns on it will stay on until the temperature set has been reached.

So if the refrigeration unit is running and the display shows above the set temperature there is only two options, either the sensor has failed, which is rare or the refrigeration unit is faulty.

If after a few minutes can be set to 10 minutes but 2 or 3 is more standard, the unit fails to start then it may be the control unit, or settings, each has slightly different methods to set them, what I found it was easy to set an upper or lower limit thinking you have set the running temperature.

I had a problem with mothers freezer, I use an energy meter to test them from time to time, so if the motor uses 100W and the freezer is rated at 195 kW/h/annum then the motor should be running for ¼ of the time, so for 24 hours looking at 600 W/h if it shows 2400 then it is not turning off, and this was the case with mothers, so wanted a STC-1000 to brew with so put sensor in freezer and showed -26°C so swapped thermostat and all was OK. However found it hard to find things to measure -18°C so to start with I put some saturated salt water in freezer as freezing point of brine is -18°C.

Today the InkBird ITC-308 has taken over from the STC-1000 as it is already housed, but it is slightly more expensive. But if your sure the motor is cycling, and is not simply running all the time a STC-1000 is around £7 so just fit a new one.

 

[stender]

I dont know what the unit is called but below is a photo from the fridge companies website. One of their engineers called me. He said it's likely either the compressor has gone (circa £800) but I don't think is the case as it sounds like it's running. or needs gassing?
The engineer was somewhere up north and wanted £180 just for a call out. He suggested I find a local commercial refrigeration engineer.