My walk-in cooler is freezing over night. What happens is I can turn the thermostat back and forth to get the cooler to kick off. The cooler will kick back on when the temp. goes above my setting but the problem is that it will not kick off when the temp falls below my setting. This is causing it to freeze up over night.
Goodmank,
It is actually freezing your walk in or it is icing up in the back? If it is the later, we used to have a problem with that when I was at Papa John’s, where the unit would condensate in the back (I think if I recall it was a problem with the charge.
Here’s an article I just found on google on it just in case this is the problem you are having:
Disclaimer: I am not a refrigeration expert, what I say here is third party hearsay.
The story I have been told is the temperature is controlled by the pressure of the refrigerant in the coils. If there is a leak and/or the refrigerant is low the compressor will continue to run trying to achieve the shut off pressure. This will cause the system to drop below the specified shut off temperature.
It is actually freezing up. dropping below 32 degrees. I think you may be right on your last post Daddio. That is what I am hearing from one AC guy
I’m not sure how accessible your system is, but there should be a small sight glass, usually on the filter dryer or in the line very close to it. If you see small bubbles flowing by, it’s a good bet that your system is low on coolant and you will need someone to recharge it.
There are only a few reasons why it would ice up.
- Your coolant is low, if this is the case, you have a leak and it is not going to be cool.
- There is a restriction of air flow. Check to be sure the coils are clean. You can buy coil cleaner from a supply house. Spray it on, let it sit and then hose it off.
- You need to replace the filter, if you have one.
If you have ice on the coils, it has to be removed first so you can have air flow.
Years ago when I first installed my walk in cooler, I had the exact same problem. My friend who does maint and repairs replaced the cheap factory thermostat with a better quality one for $50 or so. He said the tolerance is tighter with the new better one. I have had zero problem with it. I used to have to climb on top, remove the cover and pour hot water on the coils so the cooler would cool.
Your thermostat is malfunctioning.
It happens. I had one go bad after only one year. Did exactly what yours did. The refrigeration tech came out and replaced it with another one just like it (Made in Mexico) and it worked fine until I closed the store and sold the walk-in.
I have the same thermostat on my current walk-in and it’s at least 12 years old and never been replaced.
We have had 2 upright freezers (2 & 3 door) do the same and each time it has been either the thermostat or the defrost probe, with the latter making the unit keep thinking it is regenerating after defrosting and then freezing up.
We did have problems a few years ago with freezing up behind the fans in the coolroom condensor motors and this was caused by leaking gas. Replaced the motor (burnt out) and the condensor and the problem ceased
Thanks everyone. It ended up being the thermostat. Had to have it replaced.
I had a unit that had that problem for years. About 5 years ago I had a timer installed on it that would shut down for 1 hour in the middle of the night. I have not had a service call on that walkin since. Knock on wood.
I have a slightly undersized capsule pack that froze up all the time. A new thermostat helped but what really helped was installing a drain line. The evaporation pAn didn’t keep up an water backed up in the unit and froze. The ice grew rapidly on the coils. I ran a drain line to the floor outside of the cooler and I havent had to defrost in over a year.