Lamona fridge temperature too high

[davew]

I have Lamona HJA6132 integrated fridge and nocice that the temperature is generally too high.
Using a digital thermometer, the temperature at the lower of the fridge generally varies between 6.0 and 7.9.
The temperature control setting does not seem to change this actual measured temperature range.
With the thermostat sensor (long wire) removed from the housing and just left floating in the fridge, the actual measured temperature dropped to -1.
Is this an indication of a bad thermostat?

[seanf]

It could be a faulty thermostat. I would be making sure the door is sealing correctly, making sure the thermostat sensor is in the right location and checking for uneven frosting.

A photo might help/prompt other to help.

[davew]

Further investigation shows that the temperature is varying between 4.8 and 8.
The cycle seems to be:
Compressor runs - Temperature drops to 4.8
Compressor stops - Temperature rises to 8
Compressor runs - Temperature drops to 4.8
etc etc
Cycle repeats every 2-3 hours, so most of the time, the actual temperature is above the recommended 5 degrees
(This is with thermostat control set to maximum (coldest), and door only opening for a few seconds to check temperature)
Is this temperature fluctuation expected/normal behaviour???
(8 degrees seems too high to me)

[redroge]

The stat could be out of range , are you getting frost on the whole of the evaporator !

[seanf]

Further investigation shows that the temperature is varying between 4.8 and 8.
The cycle seems to be:
Compressor runs - Temperature drops to 4.8
Compressor stops - Temperature rises to 8
Compressor runs - Temperature drops to 4.8
etc etc
Cycle repeats every 2-3 hours, so most of the time, the actual temperature is above the recommended 5 degrees
(This is with thermostat control set to maximum (coldest), and door only opening for a few seconds to check temperature)
Is this temperature fluctuation expected/normal behaviour???
(8 degrees seems too high to me)

Not sure what type of digital thermometer your using but. Maybe try taking the core temperature of something that stays in the fridge like a glass of water or a lump of jelly, and if you can leave the thermometer in the water/jelly/whatever.
The differential of 3.2 Degrees sounds ok, but I would have thought you would be able to max out the stat and see it go nearer to zero or just below.

Like Redroge is asking, see what the frost on the evaporator is like. It may not be a fault with the stat.

[davew]

Thanks for your responses.
1 There is hardly any build up of frost at all.
2 With the actual temperature sensor (long wire) removed from the housing and just left floating inside the fridge, the temperature dropped to -1. I did not leave it in this state for a long time, so dont know if the temperature would drop even further, or if the temperure would fluctuate
I will try monitoring the temperature of a glass otf water as suggested

[redroge]

When the temp was -1 was the evap frosted all over or was it partially wet!

[davew]

Redroge --- I think it was frosted all over, but not 100 percent sure.
With the thermostat connected and inserted, and temp fluctuating between 4.8 and 8, most of the time, the back of the fridge is wet, rather than frosted

[frank]

What refrigerant is the unit running on?

[davew]

Frank, No idea what the refigerant is. This is a standard Lamona intergrated fridge

[davew]

Update:
The digital thermometer I'm using has an internal ane external temperature feature.The external temperature being via a wired sensor probe
I put a glass of water in the fridge and inserted the external temp probe in the water.
During the 24 hour period, the fridge temp varied between 4.7 and 7.9, the water temp varied between 5.3 and 6.3
During this period, average fridge temp was 5.7, average water temp was 5.8, which is obviously too high.

I'm inclined to take the plunge and replace the thermostat, unless anyone has any other suggestions

[seanf]

Just make sure it is the thermostat that is switching it off and on, and not the compressors klixon (compressor getting too hot or pulling too high amps or faulty klixon). And also if it is the thermostat doing the switching, that its not because of the evaporator only cooling the area round the thermostats sensor, that all of the evaporator is reasonable evenly refrigerated/frosted. You might not always catch it frosted, but if you take the temp or touch the back pannel it should be reasonable even, maybe a slight temperature gradient.

[davew]

Upadte.......
I replaced the thermostat and this has resolved the problem.
Thanks to all who responded