"NY" wrote in message
...
We have an Arctis freezer - not sure what model, but it's a tall one about
5 feet high, which was left by the previous owners of the house.

The temperature on the display used to be constant at -18 degrees C, but
over the past couple of weeks it's started fluctuating between -18 and -12
over the course of several hours. The times when it is showing a warmer
temperature are not necessarily when it has been opened; nor are they
times when the room is warmer, either because of sunlight or daily
variations in the temperature of the Aga (which also came with the house).
There are times when it's showing -12 but the compressor isn't running, so
it's not as if the refrigeration mechanism is struggling to achieve the
temperature that the thermostat is set at.

The latest in the saga of the freezer...

We noticed that it was spending longer and longer at around -14 to -12, and
less and less time at -18. Then last night the alarm went off because the
temperature had reached -11.

So we hastily moved everything into other freezers (including starting up
one that we used to use only in the summer for freezing all the veg and
fruit that we grew) and turned the misbehaving one off. When I investigated
behind a bit of trim I found that the cooling pipes in the freezer
compartment were surrounded by a large block of ice. So much for frost free
;-)

Having left the freezer off overnight, about a litre of water collected in
the vessel where it normally collects during the thaw cycle and then
evaporates in the heat of the compressor.

It looks as if the freeze/thaw cycles had stopped working properly and the
freezer was never defrosting properly before the thermostat started another
freeze cycle.

It's cooling down again now (it's gone from +21 to +8 so far) so I'll see
whether it gets to -18 and stays there. And if it starts doing it again in
the future, at least I'll know what to check.