Fisher & Paykell freezer problem

[jack in oz]

This is my first post and I would appreciate some advice.

I have a Fisher & Paykell model N210 freezer. A few months ago it wasn't freezing. After doing some research on this forum I determined that the defrost element had failed. I replaced it and the freezer seemed to be working again. I confirmed that the defrost heater was working by rotating the defrost timer to the defrost position and measuring the power consumption. It read 330 watts.


Over 2 months the freezer has been gradually getting warmer to the point where it wouldn't freeze water. I manually defrosted the freezer and it released enough water to overflow the collection tray twice. I immediately suspected the heater had failed again. However, I checked it with a multimeter and it reads 190ohms.


I then suspected the thermostat, so I removed it and 'froze' it in my other freezer. I removed it from my freezer and checked the contacts with the multimeter. The contacts were closed. After a few minutes at room temperature there was a ''click'' as the contacts opened. I guess that means the thermostat is OK.


I'm now suspecting the defrost timer is the problem. I rotate the timer with a screwdriver until I hear a loud 'click' and the compressor cuts out. However the heater element isn't being powered.
I guess it could also be a faulty wiring connector in the timer-thermostat-heater circuit. I'd like to check the timer is definitely faulty before I buy a new one.


The freezer is currently running at -13C according to my thermocouple probe. That's with the temp controller set to 7 (full cold).


I would appreciate any help.


Regards,
Jack