Clunking compressor

[Johnny Rod]

Hi guys, hope you don’t mind me popping up again after a couple of years off! I have a (hopefully) quick question about the fridge in my kitchen. It’s a Zanussi fridge freezer, about 5 years old, big silver thing with frost free and all that, weighs about a ton for some reason. One compressor as far as I can make out (not looked at the back of it in years). It has started making a loud knocking/clunking when the compressor shuts off, and lately I think the cooling capacity might be reduced, I had to adjust the thermostat and it seems to spend a long time running, though on start-up and when running it sounds more or less the same as ever and gets down to temperature successfully. Does this suggest something to you, slow leak perhaps? I haven’t’ pulled it out yet to see if it’s just that the compressor is loose or something equally simple.

[Argus]

.


John, good to hear from you after so long.

My limited knowledge of domestics is stretched to the limit, but small hermetic compressors (black pots) all share similar design characteristics.

Basically, the motor and compressor assembly is built as a single item; In small domestics fridges the whole thing is encased in a steel pressure vessel and it contains a quantity of oil. The motor-compressor assembly is generally sitting on a set of springs that allow a small amount of free movement for vibration in the space inside the chamber.

It is most likely that one of the fixing springs has given way, allowing the guts to sit in contact with its supports, hence the clunk.


Can it be fixed? Not without changing the compressor assembly and that is invasive and probably expensive. Generally, the economics dictate that it's not worth it.

Is it terminal? Not necessarily. It could go on for ages working as normal making that clunking noise, but if there's a definite deterioration in the cooling capacity evidenced by the frost line on the evaporator retreating, it's prpobably time to relegate it to be a beer-hulk in the garage.


Anyway, keep in touch.



.

[Gary]

Clean the condenser (and fan if it has one). The condenser is the warm radiator thing in back or underneath. It needs to get rid of it's heat or it will clunk when it shuts down.

[Johnny Rod]

Hi guys, thanks for the responses. I think the condenser is covered on the back but wil check it out tonight, pretty sure it doesn't have a fan.

[The MG Pony]

even if no fan you should clean it up every couple of months, the cleaner it is the better, the more freely air can flow around it the better!

[chemi-cool]

It usually happened when one of the motor support springs break and the motor hit the shell when it stops.

Nothing to worry about unless the noise bather you.

[Johnny Rod]

Well I found the condenser underneath, looks like the usual set of tubes with cross-pieces as a heat sink, but folded back and forth which makes it very good at trapping the fluff, particularly as the intake is at floor level. I de-furred it and it doesn't seem to have any trouble cooling any more (shocker) but it still clunks just the same when it shuts off. So I gues I just have to ignore it until it packs up, otherwise any idea what a ballpark replacement cost would be? Or is it pointless compared to a new fridge? This one was around £400-500 I think.
Thanks a lot
John

[taz24]

Well I found the condenser underneath, looks like the usual set of tubes with cross-pieces as a heat sink, but folded back and forth which makes it very good at trapping the fluff, particularly as the intake is at floor level. I de-furred it and it doesn't seem to have any trouble cooling any more (shocker) but it still clunks just the same when it shuts off. So I gues I just have to ignore it until it packs up, otherwise any idea what a ballpark replacement cost would be? Or is it pointless compared to a new fridge? This one was around £400-500 I think.
Thanks a lot
John


It could run lke that for years, thing is no one can predict when it will fail, but sods law dictates it will fail about an hour after you have just filled full of food.

To replace the comp you would pay about £80 to £130 ish.

Lets hope there another few years left in the girl eh??:p

Cheers taz

.

[Johnny Rod]

Thanks very much guys!