We just inherited a commercial fridge that is keeping food way too cold. I’ve never heard of a fridge doing that. What could be causing this? A sensor of some kind? The coils are clean and it doesn’t run longer than it should.
Thanks!
If you adjust the temperature dial, does it get colder? If not then the dial itself might be shorted out and the controller may think that it’s set for the coldest temperature.
The temperature sensor might be bad. The electrical connections from the sensor to the control board might also be corroded or going bad.
The controller board itself might be bad too.
I know that, for our home air conditioning system, the evaporator freezes up when it gets low on refrigerant.
Our home, not commercial, refrigerator was doing this, and it was also dripping water into the refrigerator and occasionally onto the floor. Turned out that there was a drain at the back of the freezer that had iced over. I’m not sure why that caused the refrigerator to be colder than it should have been, but my husband cleared the drain and it fixed it. There’s a ton of YouTube videos on it; apparently it’s a common problem.
1 question what is way too cold?
2nd question have you tried to adjust stat?
This has happened to me with two home refrigerators. In those cases the defrost cycle stopped working so ice built up in the interior walls where it couldn’t be seen (they were self defrosting). The ice in the walls made the refrigerator too cold. I would unplug the refrigerator for a few days so the ice could thaw, then the fridge would work OK until the ice built up again. With the ice built up in the walls it would never run so the freezer would be too warm.
It might be worth a try to see if unplugging it for a few days helps.
This is starting to sound expensive!!
Food is starting to freeze. The stat has been turned all the way down. Others were working on this and now it’s been turned over to me to fix. Wish they’d had done that to start with!!
Turned all the way down. Turn it up. Does the compressor stop?
If you know how to work around electricity? The stat should have two wires connected to it. Check the voltage across the terminals. If you have 0 volts the the switch may be fault. Disconnect one of the leads. If compressor keeps running then there is another problem.
If the compressor keeps running with full voltage across the switch or with one lead disconnected the start checking relays. You may have one with the contacts burned closed. You are going to have to go through the wiring diagram.
Motherboard…expensive, several hundred dollars. A commercial fridge may very well not have one.
Temp sensor, cheap(er) and easy to replace. The hardest part is usually routing the sensor.
Do you have a make/model.
Yes, the evap coil can freeze up as others have said but that almost always results in a warm cooler, not an overly cold one.
Finally, I wouldn’t suggest it’s running too cold until you’ve adjusted the dial to the warmest setting and it’s still running too warm.
Put a bottle of water in the fridge and get a digital probe thermometer. After a few hours, check the temp of the water. You’re aiming for 34-38ish*.
If it’s too cold, turn the dial up just a bit. Wait 24 hours and check again. Still too cold, turn it up a little more, check again. lather, rinse, repeat. This process can take several days. If you get it all the way to the highest setting and it’s still not too cold, it’s possible that it’s that t-stat isn’t working, but it could be something else. While you’re doing this, make sure the compressor is cycling on and off. If it’s always running, it’s likely a different issue.
Ignore any numbers on the dial. Over the years they’ll wander. This is, IMO, why many dials use letters instead of numbers.
FTR, I have decades of experience with this. I’m not a pro HVAC guy, but I do my own HVAC repairs at work and we have quite a few units. Walk ins, reach ins, self contained and remote units. I’m hardly a stranger to this.
Also just for the heck of it, keep an eye out for (hoar) frost around the door seals.
And again, freezing coils (which tends to indicate low freon) probably isn’t the issue).
*A common mistake is to notice that it’s running cold and turn the dial really far up, then it’s too warm, so they turn it down and it get’s too cold and they just complain and never find a happy middle. Not just with coolers but with a lot of things that heat or cool. I always suggest you just nudge it up/down a little at a time. That always works better, even if it takes longer.
Good advice.
Two things to keep in mind:
- This is for a commercial cooler. True, ZeroZone etc. Commercial units and consumer (homeowner units) are two different animals. I mean, at their heart, they operate on the same principles, but commercial units are designed to be serviced and serviced easily. Homeowner units, not so much. Quick example, I can pull out just about any electrical part in my commercial units, get a replacement part and have it back up and running in under an hour. My home fridge, last time I had a problem, I started to get worried that it might be a bad wire because all the wires were installed, sprayfoamed in place and covered with panels that I couldn’t find a way to remove. That would have made it very difficult to replace them.
2)Ask yourself why you got this. Did they give it to you because it was broken to the point because it wasn’t worth fixing anymore?