Frsot-free freezer ices up suddenly

[NY]

We have a supposedly frost-free freezer which mostly works as designed: the cooling fins on the heat-exchanger remain clear of ice. But several times over the last year, we have found the reported temperature increasing and a lot of ice around the heat-exchanger, so we have to take everything out (thank goodness for a spare freezer) and defrost/re-freeze.

There is no sign of obvious blockage in the pipe that drains the heat-exchanger to a tray above the motor/compressor.

It doesn't seem to happen at any particular time of year, and as far as we are aware, we don't store more/less food in there or open the door more at some times of year than another.

I'm intrigued what could cause a freezer to keep itself frost-free for several months (with no visible gradual build-op of ice) and then suddenly ice up.

[Tim+]

I would imagine that the commonest cause is an unnoticed obstruction to the door closing fully. It only needs a drawer to be not fully closed or an odd shaped package to be sticking out slightly to allow moist air in.

It could be an intermittently faulty defrost timer but I would imagine that it?s more common for that to either work or not work rather than develop an intermittent fault.

Tim

[The Natural Philosopher]

air leak to outside.

I've got failing seals on my fridge, and occasionally its all wet inside where it aint icy, and the temperature is 4 degrees higher than it should be

I just close the door carefully...

[S Viemeister]

Yes, we've had that happen upon occasion.

[Peter Johnson]

Exactly the same with mine at the moment. I asked a question about it a while ago.No obvious cause. Took everything out, defrosted/refrosted and it was all OK until I noticed that it had frosted up again a few days ago, but it would have been doing that for a while before I noticed. In my case, the only thing I can think of it that the room it is in gets the sun on it in the afternoon so the ambient temperature is much higher than it is used to during the summer.

[Martin Brown]

It is almost certainly a failure of the seal somewhere. It doesn't take much of a gap to end up with a lot of water vapour frozen inside the freezer and very *MUCH* more than the self defrost logic can cope with.

Our fridge suffers the same mode of failure when there is too much weight in the door. It doesn't quite seal on the magnetic clamp.

The oversize tropicana orange juice containers seem to be a problem.

[Brian Gaff (Sofa]

A leak in the door seal, ie the door does not always seal correctly. Leave it open a crack and see what occurs, I did theirs accidentally, and the result was ice inside and of course around where the leak was. Bah humbug. Does it have a fan that might occasionally jam up? Brian

[Brian Gaff (Sofa]

Who freezes orange juice or milk? Actually, I removed one of the door shelves to gain a bit more depth in the freezer. Brian

[AnthonyL]

[NY]

Yes I freeze milk: we sometimes buy more milk than we need for the week and freeze it in screw-lid containers of about 300 ml, to keep some in reserve. The main thing is to remember to take out a container of frozen milk 24 hour before I'll need it on my breakfast cereal, to let it thaw in the fridge. It means that if we don't manage to get out to a supermarket, there's still milk for breakfast. Also, if we are ever going on holiday, we freeze whatever is left: a) so it isn't wasted and b) so there's milk for breakfast if we haven't called in to a shop to buy any on our way home from holiday.

Frozen milk turns a rather repulsive yellow colour, but that reverses when it thaws. As with any frozen liquid, make sure you leave enough expansion room in the container because frozen milk takes up more space than liquid milk.

[Roger Hayter]

I'm surprised it keeps that long without autoxidation and rancidity.

[AnthonyL]

I'm looking forward to trying my 1972 vintage.

[AnthonyL]

We buy the large 4l containers then pour that into our stock of 1 pint containers, leaving enough spare to squeeze a bit of air out before tightening the lid. The small containers are washed after use and a light Milton rinse.

The upper shelf of the fridge has a defrosting pint which is then moved to the lower shelf when that one is finished. The upper shelf is replenished.

Works well and careful microwave defrost takes care of the odd oversight.

Originally started doing this when the milkman was inconsistent in the

1980's and would come after we'd gone to work - leaving the bottles outside to go rancid or feed the blue t*ts.

Freeze sliced bread too.

Going back to the OP our freezer in the fridge/freezer doesn't auto defrost as it should. Maybe it is seals. Every couple of months or so I have to move everything into the spare freezer and then defrost overnight. Usually a litre of water comes out of the pipe at the back.

Nice blast of air when it is set working again with temperatures at

-20degC. Then bit by bit the air flow drops and the temperature rises to -12decC which is where it is now so tonight's planned defrost is a bit overdue.

Unit, Zanussi Electrolux, came with the house which we bought 5yrs ago. Only thing that deters replacing it is SWMBO's hope is for a totally new kitchen and we wouldn't want it designed around a fridge.

[AnthonyL]

I've just defrosted our fridge/freezer, a job that needs doing ~ every

2 months though last done 3 months ago. I need to put the two pipes that go into the evaporation tray into a small bucket. Two litres of water came out overnight.

The freezer pipe has a small plastic insert which seems to contain an inverted soft plastic cone which I guess acts as a non-return valve (letting water out via the wide edge but not letting it back again?).

There is no such insert on the fridge pipe but the unit came with the house and so I don't know the history and whether it's gone missing.

Anyway I'm removing it and see if that makes a difference on the theory that the auto-defrosted water is not draining and then freezing thus defeating any auto-defrost function. I've missed a trick by not putting the pipes into different containers to be sure which one is draining water.

If the plastic inserts are needed I don't know what they are called or where to get them from.