We have a ZX99 that has been reliable for 4 years.
Recently it had started beeping. A power-off reset would clear the alarms for a few hours and then they would come back.
I got an electronic thermometer and the fridge was at +7C and the freezer at -2C. I took the cover off the lower back and cleaned there and the vents at the front. I turned both dials down to min.
For 12 hrs the temperature didn't change from the above but then (with nothing being touched) it went to -1C for the fridge and -10C for the freezer within the next 12 hrs.
I turned the fridge up slightly and it went to 0C but the freezer went up to -2C but it wasn't touched. This took 4 hrs.

Is it the compressor, one of the thermostats, switches, control panel or anything else. It has me baffled.

Ian, May 2009

Thanks for the above info.

Since cleaning out the condensor and the fan, the fridge has been spot on 5C. The freezer started out at -15C but rose gradually to -4C. It was like this for 2 days, moving between -4 and -8. I took everything out of it and this morning it is -22C with nothing else being touched.

Once again I am perplexed and any ideas gratefully received.

Ian, May 2009

manually defrost this for 24hrs and leave both doors open.restart the appliance and see if fridge and freezer temperature go to normal approx 4 deg c fridge and -18 deg c freezer.if it does then this is an indication that the sensors or defrost heater is up the spout for sure

ck, May 2009

evapourator sensor faulty or possible defrost heater faulty.complete strip down of the top part inside the freezer required to gain access to components.big diy job.around £100 fitted

ck, May 2009