Kegerator Coil Freezing

[808brew]

I have a Beverage Air Kegerator and yesterday, I found it was not cooling and when I looked inside I found the upper box that covers the coil was covered in ice. I am assuming that this was also the case inside. I defrosted it and started it back up but today I am back to the same problem again. I know little about refrigeration and would like to understand what I am dealing with to be able to take it somewhere. I am assuming that this is a refrtigerant problem. Is it possibly too low and needs more? Any thoughts?

Thanks

[Blowmax10]

Here is what I was able to get from google...

You have a bad defrost timer or a bad defrost heater.

ok so you need to defrost the coils with a hair dryer. Then look for any and all air leaks such as the door not sealing tightly or something similar, possibly opening and closing the door to much to build up frost inside the unit.

I know its not much but this might not be the best forum to post this question on

[Quin]

+1 on bad defrost timer or a bad defrost heater.

[Crackin]

+2

The coils rely on a heater element, located below them, to defrosts them every so often. This heater element is controlled by a timer. If you can locate the element, which usually looks like a long glass tube, you can probably check for conductivity with the ohm setting on your multi meter. A bad element is probably broken and will not show conductivity. If the element shows conductivity of any reasonable degree, then I would look into replacing the defrost timer first. Make sure you unplug things before fiddling.

[ajdelange]

There are several possible causes for this. One could be as simple as a gasket leak or opening the door too much. Others could be failure of the thermostat, refrigerant metering valve (if there is one), defrost timer, defrost heater (if there is one), defrost solenoid valve (if it's gas defrost) etc. If you don't know anything about refrigeration the best bet is to call in a service guy. They have the equipment (fairly elaborate) and experience to diagnose and repair. There are a lot of very restrictive laws about releasing refrigerant into the atmosphere in place these days so if it is anything beyond replacement of a defrost timer or thermostat you are pretty much stuch with using a pro.

I guess I'd start by defrosting it (unplug and let the ice melt) thoroughly then plug it back in, shut the door and monitor it. The compressor should run for a while (may be an hour or more) and then stop. If it doesn't then the thermostat is probably at fault (not detecting that it's cold in there) in which case you could try replacing that. Another possibility is that the thermostatic expansion valve (if the unit has one) has failed open or that the temperature sensing bulb associated with that device has come free from whichever part of the cooling circuit it is supposed to be attached to. If the compressor cycles normally but frost eventually builds up then it is probably the defrost timer which is something else you can replace yourself (if anyone will sell you the part) It could also be the heater element (of which you can check the continuity as suggested by Crackin). If it's gas defrost then it may be the defrost solenoid which is in the refrigerant lines and would have to be replaced by a professional (if cleaning the electrical contact doesn't work which is does in a surprising number of cases - and not just in refrigeration systems).

With a fancy unit like this one it is probable that all the control functions (themostat, defrost, circulating fan...) are done on a control board of some sort. Replacing that may be what is required. The more I think about the more I think describing your problem to a qualified service man is a better option than describing it to us.