Why is my freezer frosting up???

For the past year my freezer (part of fridge/freezer) was fine. No frost.
Then about a month ago the fan in the back of the freezer (insider the actual freezer, not part of the compressor) started whirring..possible ice build up? It’s behind a plastic cover/ducting cover. I gave it a whack, and it sounded like ice dislodged and the fan span fine again.
However, now the TOP tray, and a bit of the second tray, are frosting up with light ‘snow’.

The seals are clean, and there is a vacuum seal when I shut the door, but…that seems to go after a few hours, and the door opens fairly easily after a while (i.e possibly the seal/suction ‘goes’?)

Where should I invest my efforts?

Taking the plastic fan/ducting cover off? Would an internal fan affect the antifrost properties?

How can i make the door seal better? It’s clean and intact…

Ta for input!!!

DrP

Taking the plastic fan/ducting cover off? Would an internal fan affect the antifrost properties?

Yes. The fan probably circulates warm air around the back of the freezer to defrost it, and the melted ice then drains out the bottom of the freezer to evaporate.

^^^ As above, sounds like a thorough defrost is in order to clear any ice build up on the fan (if there is frosting elsewhere, you can be sure there will be around the fan too).

I think you have too many sausages in there?

Will take the ducting off and see if the air flows freely.

Whilst it’s off, and the food is out, anyone want any sausages??!!!

DrP

The seals are clean, and there is a vacuum seal when I shut the door, but…that seems to go after a few hours, and the door opens fairly easily after a while (i.e possibly the seal/suction ‘goes’?)

There’s not meant to be suction inside the freezer, it’s not a suction seal just magnetic. When you open the door, cold air comes out of the freezer and some warm air goes in which is of course less dense. When you shut it again the warm air cools down and contracts quite quickly creating a lower pressure on the inside which is why the door is harder to re-open after you’ve open and shut it once. However the door seal isn’t hermetic so after a few minutes more air has seeped in to equalize the pressure.

If you never opened it it wouldn’t frost up, but it’s going in and out that introduces water vapour and that is what causes the frost. It’s worse in summer because whilst the relative humidity is probably lower, the absolute humidity i.e. the actual amount of water vapour in the air is higher. So when it’s cooled down to -18C there’s much more vapour to form ice.

The freezer part has some heaters mixed in there to periodically heat and take any ice off the cooling cools and condense them. if the rain is blocked it’ll just refreeze again. The ice gets bigger and bigger and just doesn’t work. Easy fix in one way. Just turn it off and let It defrost for a few days. its usually ice that has blocked the drain hole.

oh and enjoy eating all the food beforehand!

You can take the ducting off and accelerate the process, but I advise against not putting a hairdryer in there as it’ll melt the door.

Can you tell I’ve had experience of this?

it may ee some other junk in the drain so might be worth a check once you’ve got the ice melted

Go to Go Outdoors and buy a big American style cooler (ours is labelled a ‘5 day cooler’ somewhat optimistically). This will easily keep it frozen long enough to defrost the freezer without having to eat all the food.

To accelerate the melting significantly use a fan without heat blowing room temperature air into the freezer. If done on a hot day it will air-condition your kitchen also.

What you need to do is get the scraper that you use for the car windows and casually hack away at the ice inside while the contents of the freezer are sitting in a duvet-wrapped cardboard box in the kitchen.
It’s best to time the fairly predictable hiss from you puncturing the inner with your wife telling you her waters have broken…

Door seal may have developed a gap letting warm air in

There will be a small heater pad to defrost the tray under the heat exchanger unit check that that is still functioning. Our AEG one eats these regularly, unless the part has been improved ours is due another replacement soon.

Also what Killer said, blocked drain to evaporator tray can cause ice build up.

As above either the door seals not sealing properly of the drain is blocked or obstructed in some way as the most obvious causes.

Most freezers use the heat kicked out of the heat exchanger on the back for preventing ice build up so its usually a pretty passive process.

Seal issue?

see… i wonder if it’s seal, as teh frosting is clearly from the top down… I’ve a chilly-tek cool box so will stick everything in there and take the ducting off..

will also see if i can temporarily seal the (er) seal – maybe a little rim of silicone at the top. It might just add enough interference to seal it?

Cheers for the tips

DrP

I had the same thing happen on a relatively new freezer and it just needed to be defrosted as the fan circulating the air to facilitate a frost free environment had frozen.

Surely buy another fridge freezer to put the food in while you defrost this one ..

Seriously a defrosting is what you need as ice forms on the condenser I think and makes it inefficient ..

It could be due to a low refrigerant level. Get it checked and topped up if neccesary.