Please help, fridge cycling

[johnno]

Hi all,

Please accept my apologies but I am not a refrigeration engineer, I am only “Joe public” but I need your help if at all possible. I have trawled the internet looking for answers and came across your site, you seem to be a community that is willing to help each other,(which is rare) perhaps you could share your knowledge with me.

I have a built-in domestic NEC fridge (type K15R18A E-NR K45130GB/03) that is playing up, it cools OK but does not maintain its temperature. It is cycling between about +10 and -3 degrees over a 4 hour period. Its starts to re-cool automatically again but then shuts down completely only re-cooling once it has warmed back up. Altering the thermostat does not kick the compressor into life, it’s as if it has tripped out.
If it is cooling (hear the compressor running) and I move the thermostat, the compressor immediately shuts down, and will not come back on irrespective of the thermostat setting until it has warmed up!

I have changed the thermostat but the symptoms are the same, it cools down OK, turns off, warms up, cools down and so on, altering the thermostat kills it etc.

Could it be the starter for the compressor or do they just stop working completely?

Any ideas would be greatly appreciated; Its in good condition (if it worked properly ) and I’m desperately tying to avoid spending £450 on a replacement when it could be mended.

Thank you

[davej]

hi johnno,

once you terminate the stat it will stay off until the evap reach +3 degrees c in order to complete a defrost,

so its important to confirm when it goes off if it is going off on the stat or an internal compressor overload.

erattic operation very often proves to be shortage of refrigerant as they work on evaporating temp of the plate unless the stat senses around -10 to -20 (varies slightly between models) the stat wont cut out and produce in products the bottom of the fridge can start to freeze, but the compressor tends to trip on an overload having been running for longer periods, and stay off longer than it should. try to confirm what it is cycling on.

[davecool]

hi johnno,

does it have a little fan blown condensor unit???
if so check that the fan is operating with the compressor and that the condensor fins or coils are not covered in dirt, maybe you have a ventilation problem as this will cause no end of bother

[shark26]

If you cant get it fixed this company can get you another one delivered to your door. They are close to you in Gloucestershire.

www.displayrefrigeration.co.uk

[dogma]

Hi mate. If you have a manifold set wack it on suction and bridge the relay. Should let you know if its low on juice. Or buy a $50 multimeter that checks caps.

Hope this helps

[Peter_1]

Hi all,
Please accept my apologies but I am not a refrigeration engineer, I am only “Joe public” but I need your help if at all possible. I have trawled the internet looking for answers and came across your site, you seem to be a community that is willing to help each other,(which is rare) perhaps you could share your knowledge with me.

Don't apologise for anything, could everybody join our forum the way you're doing it.
We're indeed a forum that's here to help others which is indeed rare.
You're coming from a place with the same name of the sauce we're having here in our fridge in Belgium.

The answer of Davej was already the answer I should give. An automatic defrost thermostats waits every time to restart till the bulb feels a temperature somewhat around 5°C (different per type)

Bridge once the thermostat leads with a normal switch and watch the temperatures.
It's known that a dometsic fridge has a big temperature swing due to the automatic defrost.
There excists thermostats that have a lower cu-in temperature.

If you turn the thermostat to the coldest position, does the compressor run then wthout stopping (test at least some hours) and is it cooling then also very good? This can give you an idea if the compressor is working fine.

Provide some more answers so that we can help you further.

[Andy]

Hi johnno

what age is the fridge, anymore than 3 years it is probably not economic to fix

Possible cause is a faulty compressor motor that is taking out the klixon (bimetal strip type current overload) with the compressor restarting when the klixon cools.

Kind Regards. Andy.

[chillin out]

It is cycling between about +10 and -3 degrees over a 4 hour period.

Sounds ok to me, I take it you are measuring the air temp?

Put a glass of water inside and put you thermometer probe in the water and take the temp.

Make sure you are not using one of them el-cheapo thermometers (dial type or plastic one).

Also make sure the door is closing properly.

The fridge door.... not the cupboard door.

To test this put a dab of lipstick on the 4 corners and in the middles of the seal and close the door normaly. If it leaves an imprint on the frame then all is ok.

Also clean the fan at the bottom and make sure there is PLENTY of air alowed to flow.

Chillin

[shark26]

Is that your excuse for carrying lipstick around !

[johnno]

Hi Guys, sorry for the delay in getting back to you I’ve been out of the country. Thanks for your replies some of which I’m sorry to say I just didn’t understand, but I did pick up on the fact that I was measuring the air temp with one of those metal dial thermometers . I have since placed a glass thermometer within a glass of water on the bottom shelf.
I have taken your advice, turned the thermostat right up and the glass of water froze solid, the temperature remained at a constant -8 C to -10 C and the compressor ran continuously for about 4 days. I have now returned the thermostat to the middle position, the glass of water has stated to defrost but there is still a core of ice in it, it has been like this for 2 days now.
The temperature and fridge still fluctuates and behaves as before. Internal air temp goes up to about +10 C and then down again -3C. Sorry of the dumb answers does this shed any light on things?

[chillin out]

Internal air temp goes up to about +10 C and then down again -3C.

This is ok, they will all do this.

Chillin

[chillin out]

Is that your excuse for carrying lipstick around !

Yes.

And if some accidently applies itself to my face...well that can`t be helped.

Chillin

[liverpool Eng]

If the fridge is empty then the air temp will swing quite a lot as the coil clears itself when the set temp is reached.
Normaly the product keeps the temp low in the off cycle giving a better air reading, meanin that you wouldnot see the swing.

[frank]

Yes.

And if some accidently applies itself to my face...well that can`t be helped.

Chillin

Just don't get it on the collar of your shirt - or the missus will think you've been up to something

[davej]

Hi johnno, domestic fridges work mainly on evaporating temperature and consequantly if the system is slightly short of refirgerant you can get this situation until it loses sufficently more gas and ceases to refrigerate correctly, also if the compressor is slightly down on its abillity to pump you can get a similar effect. its difficult to be more specific witout knowing if the evap is frosting all the way through, fitting a gauge would tell you all you need to know, failing that for about 12 quid buy a stat and fit it to iron out possibillity of stat losing it charge and becoming inaccurate.