I have a 20 year old Hotpoint RF60 2-door upright fridge freezer. The
bottom half is the freezer and the top half is the fridge. There's only
one compessor, and a single electro-mechanical thermostat in the fridge is
the only temp control for the whole unit; it's sensor tube is attached to
the rear of the heat exchanger in the fridge compartment.
Last week the thermostat packed up. I called a repair firm and they
changed the thermostat. However, even on its warmest setting, the freezer
is at -24C (at least - end of thermometer scale) and the fridge is colder
than I would like - naturally, the compressor is running for much of the
time but the unit does go through a cycle i.e there are times when the
compressor is off and the heat exchanger in the fridge defrosts itself.
However, something's not right. Yesterday, the firm replaced the new
thermostat but the unit is still running too cold.
To try and understand how the thermostat works, I partly stripped the old
defective one. The outer 2 contacts appear to be controlled by the
bellows at the end of the sensor tube. However, there is a central
contact which seems to be connected to one of the edge contacts at all times
except when the thermostat is turned to Off. I don't understand what this
central contact is for.
There are 2 factory preset screws which control spring tensions and I
presume these screws control the temp at which the compressor contacts make
and break. One's accessible on the top of the thermostat and the other's
visible through a hole adjacent to the first screw. I'd be grateful for
advice on how best to go about adjusting these so that with the user control
knob in the middle of its scale, I have a freezer temp of around -18C and a
correspondingly cool fridge.
I've tried phoning Hotpoint for help but there is no technical department.
Any guidance and clarification would be much appreciated.