Fridge Mechanic Advice Needed

[Ducatiboy stu]

Well my kitchen fridge is playing up, and if there are any fridgie's out there, I need your advice.

Bascially the fridge section is not getting cold. The freezer above is working fine, but the fridge section stays about 12-15* and I dont really want to have to get a new fridge if it is repairable.


And please keep the "fermenter fridge" comments to a minimum....

 

[Frank]

I'm not a Fridge Mechanic, but the first thing you will need to do is pull your fridge out from the wall and have a look underneath. See if there is any liquid that has leaked out of the copper coils, (ofter green in colour, like radiator coolant). If there is you have lost the gas for the compressor. If you can't see any liquid that has been lost, next step is the thermostat. Genuine thermostats can often be over $100 plus installation. An external 'Fridge Mate' for around $45 would get you by, but still need to pay for the installation.
This is where my help stops.

 

[Gulf Brewery]

"fermenter fridge"


Someone had to say it and I kept the font as small as I could - is that what you meant?

Pedro

 

[Ducatiboy stu]

i think it has something to do with the auto defrost cycle, as the tube/pipe from the freezer to the fridge that supplies cold air is freezing up, blocking the air flow...and it aint easy to pull apart as the shell is filled with fill-a-foam so you cant even remove the back or sides...

 

[katzke]

Bascially the fridge section is not getting cold. The freezer above is working fine, but the fridge section stays about 12-15* and I dont really want to have to get a new fridge if it is repairable.

Not an expert but I have read some of the fridges have an air valve type of thermostat that lets cold air in from the freezer. If the freezer is cold that could be your problem. If you have a place to put the food you could try defrosting the thing, or just unplug it and poke around that part of the fridge. Seems like I have heard of the passage getting clogged up or something. As long as you do not get carried away it sounds like you can not hurt anything by giving it a look.

 

[lefty2446]

i think it has something to do with the auto defrost cycle, as the tube/pipe from the freezer to the fridge that supplies cold air is freezing up, blocking the air flow...and it aint easy to pull apart as the shell is filled with fill-a-foam so you cant even remove the back or sides...

I am a fridgie with experience in domesitic fridges.

If that air tube is freewzing up here are some things to check.

1) Thermostat is fine because the fridge is _Working_ - mostly thermostats fail open - (Stopped)

1a) There are 2 air paths to the fridge, a supply and a return, check both for flow - a hairdryer on warm only is good for this. (see also #2) the return aur duct usually fills with water and freezes if you have a blocked drain meaning no return air from the fridge.

2) Check the bottom of the evaporator up the back of the freezer and se of there is a puddle of ice, if there is, clear it out with hot water and clear the drain tube.

3) If the evaporator is a solid block of ice (or close) then you have defrost problems, mostly defrost termination thermostat, sometimes defrost heater or defrost timer.

4) if nothing is blocked up and you only have ice on half the evaporator and the rest isn't sticky with a wet finger then you most likly have an ineficient compressor - it's now a fermenting fridge.

If you need more help than this let me know.

Adrian

 

[Ducatiboy stu]

well it seems after having more of a play, that the plate heaters connencted to the defrost timer are stuffed. It kept tripping the main cct breaker in the switchboard, and when I disconnected the timer and bridged the wiring to get the comp working all seemed fine, untill the fridge started to get warm, which makes me think that the air paths are freezing up. When I turned it off for the day, the fridge section started to get cold again..

I am not looking forward to getting those heaters out....
You can see the timer I bypassed circled in red, and the heaters in orange...

 

[Simon W]

Not a fridgie, but if the heaters were s/c, then they'd blow that fuse in their circuit wouldn't they?
Maybe there's an earth leakage issue somewhere in the defrost cct?

 

[lefty2446]

well it seems after having more of a play, that the plate heaters connencted to the defrost timer are stuffed. It kept tripping the main cct breaker in the switchboard, and when I disconnected the timer and bridged the wiring to get the comp working all seemed fine, untill the fridge started to get warm, which makes me think that the air paths are freezing up. When I turned it off for the day, the fridge section started to get cold again..

I am not looking forward to getting those heaters out....
You can see the timer I bypassed circled in red, and the heaters in orange...


View attachment 20903

I can't think of why the fridge would start to get warm again but the air paths freezing up on their own is _not_ vry common. usually they freeze up because the drain is blocked and during a defrost water fills the drain tray. When the defrost is done this water then freezes blocking the return vent.

Did you check for air flow through the vents with a hair drier?

Also it sounds like the defrost heaters may be leaking to earth (not an uncommon fault). I don't know how you'd test this without a propper megohm meter.

Was the evaporator (cooling fins) a block of ice when you pulled it apart?

Not a fridgie, but if the heaters were s/c, then they'd blow that fuse in their circuit wouldn't they?
Maybe there's an earth leakage issue somewhere in the defrost cct?

That fuse is a thernal fuse designed to open circuit if the defrost thermostat dosen't open when the defrost is done (saves the fridge becoming an oven and catching fire)

Adrian

 

[Ducatiboy stu]

Havent pulled it apart as such, just checked what I could underneath, I think that to get at everything I will have to go via the inside of the fridge, as the back and sides are one big chunk of filla-foam... :angry: . Its one of those auto defrost jobs...have never seen ice built up in the freezer...

Dont have a Mega ( but could get one ), so I am not sure if it is s/c or earth leakage...


The fridge only gradually gets warm..takes a few days. The first couple of days, it is nice and cool

 

[lefty2446]

Yep, pull everything out of the freezer and start from there, it's the only way to get to the crux of your problem. Although now you have turned it off for a day posibly the tell tale signs I asked you to look for are gone <_< .

But try it and see.

Adrian

 

[Ducatiboy stu]

Something not right...but simple..

Fridge section is warming up, but freezer is cold as Antarctia.....

Can hear the fans working in the fridge...




:angry:

 

[lefty2446]

Then your still in luck, the fault is still there.

You'll have to pull the freezer apart and have a look, especially under the aluninium finned evaporator for a puffle of ice. It's the only way.

Adrian

 

[SDJ]

I had the same sort of thing happen to my keg fridge, I ended up testing the defrost heater and the thermostat, both where fine, I ripped the mechanical defrost timer out of an old dead fridge and I have not had to defrost my fridge again.

 

[Ducatiboy stu]

i managed to pull the inside apart, and found that the chiller plates are frozen, and the air duct is definatly not blocked...and the fan blows air thru it...


So what I am thinking is that when the plates ice up, you loose the cooling effect and its not actually blowing cold air, just air off the ice which is not really that cold...so this would mean that the defrost heater plates are stuffed...BUT which heater is stuffed....

 

[mika]

I was told with one of my fridges that exhibited this trait, that as fridges run out of gas, the fridge section gets warm and the freezer section if on top will still work fine or in some cases get even colder than it should. Sounds like it's stuffed Stu.

 

[lefty2446]

i managed to pull the inside apart, and found that the chiller plates are frozen, and the air duct is definatly not blocked...and the fan blows air thru it...


So what I am thinking is that when the plates ice up, you loose the cooling effect and its not actually blowing cold air, just air off the ice which is not really that cold...so this would mean that the defrost heater plates are stuffed...BUT which heater is stuffed....View attachment 20920

ITSA LG , Good fridge to tell you the truth. The heater is wrapped in amongst the evaporator, each end has a red wire coming from it to a plug. But first you need to check the defrost thermostat assy. Its the plastic bag on the RHS with 3 wires coming from it and is most likely the culprit. One wire Brown is common and while it's cold you should have a circuit (low ohms) to each of the other wires Red and Orange. I'm going to predict that the thermal fuse (smallish wire looking thing) inside the plastic bag) has been too hot and open circuited not allowing power to the defrost heaters.

To check this turn the fridge off and leave it in place (so it stays cold) unplug it and check it with a multimeter.

I was told with one of my fridges that exhibited this trait, that as fridges run out of gas, the fridge section gets warm and the freezer section if on top will still work fine or in some cases get even colder than it should. Sounds like it's stuffed Stu.

This fridge is quite fixable with cheap parts, If the fridge had run out of gas then the evaporator (last picture provided) wouldn't be a solid block of ice. His problem is airflow.
(from not defrosting properly).

Adrian

 

[Ducatiboy stu]

I Fixed it....

Cost me nothing

If you look at the top terminal of the defrost timer , you can see why it was tripping the ELCB...


The simplest things are always in the last place you look h34r:

 

[katzke]

I Fixed it....

Cost me nothing

If you look at the top terminal of the defrost timer , you can see why it was tripping the ELCB...View attachment 20922


The simplest things are always in the last place you look h34r:

Now that you have saved all that money on not getting a new fridge you can spend some on more brew equipment. How about a new fridge for fermenting in? Summer is coming you know.

And people say brewing is an expensive hobby. Where else could you get advice on fixing your fridge then on a beer forum? Any advice on a 16 year old TV?

 

[lefty2446]

I Fixed it....

Cost me nothing

The simplest things are always in the last place you look h34r:

Never would have guessed that, In 4 years of fixing LG's I never had a defrost timer trip an ELCB! You did well to find it.

Now your return ducts are under all that ice below the evaporator, be sure to clear all the ice away and check that the drain tube isn't blocked with ice as well. Hot water from the tap is the fastest way.

Adrian