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Hi
Problems with fridge and freezer. Initially it started frosting up so I tested the defrost timer, found it faulty, and replaced it. I then found that when in the defrost cycle the heater was staying on the for the full defrost period (20min) causing the freezer and fridge compartments to warm up. Suspecting the thermostat/thermister connected to the heater element I replaced it (comes as a single unit). However I’m still getting the problem where the freezer and fridge are too warm. If I remove the defrost heater the freezer and fridge cool down, and after two days the the freezer frosts up (stopping air circulation into the freezer).
I’m not sure of my next options – it appears that the defrost occurs every 8 hours for 20 minutes – which may be too often – could this be a problem with the temperature control?
Are their any tests I can do armed with a mulitmeter?
Thanks in advance – very useful and interesting forum.
Re: Admiral GC2227CDFW fridge/freezer defrost and cooling
Are you sure that you have the correct defrost timer and that it is wired correctly?
Most will run on an 8, 12 or 24 hour cycle so, eight hours is fairly normal.
But it sounds, form what you describe, as if the defrost heater is being run all the time.
And no, it won’t be the thermostat that would be causing that.
K.
Re: Admiral GC2227CDFW fridge/freezer defrost and cooling
Hi K – Thanks for the reply
Its the correct defrost timer, and its wired correctly – the compressor runs for 8 hours, and then I get 20 minutes of heater. I’ve used a temperature gun to establish then when the compressor is off, the heater is on, and vice versa.
I replaced the heater and thermostat because the heater was running for the full 20 minutes. It should only run until the ice on the coils has defrosted, which is sensed by the thermostat.
Also my understanding is that the defost timer should schedule the 20 min defrost for every 8 hours of compressor operation – not 8 hours elapsed time – it apepars to be every 8 hours of elapsed time at the moment. Hence my query on the temperature control as that dictates when the compressor runs?
Regards
Jim
Re: Admiral GC2227CDFW fridge/freezer defrost and cooling
I think you may have made a few incorrect assumptions here.
The compressor runtime is not eight hours. The compressor runtime is controlled by the main freezer or fridge thermostat, should be the freezer one in that machine from what I can see with the cool air from the fridge being drawn off from the freezer by way of a baffle.
The compressor will not or, should not, run for eight hours solid. If it is, there’s a refrigeration system issue given it’s not cooling correctly. It also means that, in all probability, there is no problem with the thermostat.
A temperature gun or thermostat won’t tell you what’s running, just what the temperature is. 😉
Often with the old Maytag and Admiral units the defrost timer will prevent the compressor running during the defrost and bring on the heater full pelt. It can on some glow red it gets that warm and you’ll hear hissing as the water melts and hits it.
After that completes the compressor is kicked back in and cooling starts again.
The defrost heater should not be energised at that point or until the next defrost.
If it is, there’s a wiring problem or a problem with the timer.
HTH
K.
Re: Admiral GC2227CDFW fridge/freezer defrost and cooling
“I think you may have made a few incorrect assumptions here.” – They do say a little bit of knowledge is a dangerous thing! 😀
“The compressor runtime is not eight hours. The compressor runtime is controlled by the main freezer or fridge thermostat, should be the freezer one in that machine from what I can see with the cool air from the fridge being drawn off from the freezer by way of a baffle.”
I’d appreciate if you could clarify my misunderstanding on the defrost timer – does it continuously run 8hrs in compressor mode, 20 min in defrost mode – or does it schedule a 20 minute defrost for every 8 hours of compressor operation (which could be 16 hours elapsed time).
“The compressor will not or, should not, run for eight hours solid. If it is, there’s a refrigeration system issue given it’s not cooling correctly. It also means that, in all probability, there is no problem with the thermostat.”
The refrigerator does cool, however it may not be cooling correctly as you suggest.
“A temperature gun or thermostat won’t tell you what’s running, just what the temperature is. ;)”
I’d disagree slightly in that it will tell me when the heater element is hot, and when its cold – mind you it glows red as well when its hot!
“Often with the old Maytag and Admiral units the defrost timer will prevent the compressor running during the defrost and bring on the heater full pelt. It can on some glow red it gets that warm and you’ll hear hissing as the water melts and hits it.”
“After that completes the compressor is kicked back in and cooling starts again.”
“The defrost heater should not be energised at that point or until the next defrost.”
All 3 paragraphs above appear to be the case – the compressor does not run during the defrost cycle – the heater goes red and defrosts, and the heater is off when the next compressor cycle is on.
“If it is, there’s a wiring problem or a problem with the timer.”
I appreciate I am taking up a fair bit of your time, so thanks for that.
HTH
K.
Re: Admiral GC2227CDFW fridge/freezer defrost and cooling
jimm wrote:I’d appreciate if you could clarify my misunderstanding on the defrost timer – does it continuously run 8hrs in compressor mode, 20 min in defrost mode – or does it schedule a 20 minute defrost for every 8 hours of compressor operation (which could be 16 hours elapsed time).
The defrost timer in that type of US unit is a pretty dumb device.
It switches on defrost.
It switches off defrost.
Much in the same way an old clockwork timer operates on a cam (IIRC) inside the timer unit at a pre-determined interval.
That’s about it really, all there is to say about it.
jimm wrote:The refrigerator does cool, however it may not be cooling correctly as you suggest.
That would be my presumption from what you’ve said thus far.
jimm wrote:I’d disagree slightly in that it will tell me when the heater element is hot, and when its cold – mind you it glows red as well when its hot!
Exactly, you can tell anyway if the element is operational.
You can’t tell if the rest is that way or, at least not if you don’t know what you’re looking at.
jimm wrote:All 3 paragraphs above appear to be the case – the compressor does not run during the defrost cycle – the heater goes red and defrosts, and the heater is off when the next compressor cycle is on.
That should be correct apart from the fact that it isn’t cooling correctly, which is a different kettle of fish to a defrost issue.
K.
Re: Admiral GC2227CDFW fridge/freezer defrost and cooling
Thanks once again.
Could you humour me for my last desperate stab at finding something I can diagnose/fix before calling in a specialist.
If its not cooling correctly could the thermostat be the reason – i.e. its cutting the compressor out early, and not allowing the compressor to run sufficiently long enough
to cool the system. I haven’t actually monitored continually if the compressor is running continuously during the 8 hour compressor cycle – just spot checked every couple of hours.Or is it simply that the efficiency of the compressor is lower so that it cannot cool the freezer/fridge as fast as it used to.
When I remove the defrost heater it does cool the freezer and fridge down (I’ll check the temperatures, but in my mind it was in the – 30’s/40’s for the freezer, and +4 for the fridge.
Regards
JimRe: Admiral GC2227CDFW fridge/freezer defrost and cooling
jimm wrote:Could you humour me for my last desperate stab at finding something I can diagnose/fix before calling in a specialist.
That may be the only option.
jimm wrote:If its not cooling correctly could the thermostat be the reason – i.e. its cutting the compressor out early, and not allowing the compressor to run sufficiently long enough to cool the system.
No.
A thermostat will be, for the most part, a simple on/off device. It either works or not, no in between.
jimm wrote:Or is it simply that the efficiency of the compressor is lower so that it cannot cool the freezer/fridge as fast as it used to.
Quite possibly.
jimm wrote:When I remove the defrost heater it does cool the freezer and fridge down (I’ll check the temperatures, but in my mind it was in the – 30’s/40’s for the freezer, and +4 for the fridge.
+2-5?C for the fridge mean temperature dependant on setting.
-18?C mean for the freezer.
K.
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