Issue with Pizza Prep Table

My pizza prep table has been having trouble cooling as of late (barely able to reach ~38), and during the rush would struggle to bring back down to temperature. I originally attributed to the extra hot Florida weather, an issue with the air conditioning unit at our new location. Had our contracted AC Refrigeration company perform their maintenance on it Tuesday of last week, and he said the coils were dirty but appeared fine.

Friday it hit 60+ degrees (never had that before), and never cooled back down overnight. Fan appeared to be running hot. Tech came out that Saturday (we had iced inside to keep product to temp), and said it appeared to be running fine. Still didn’t work the rest of that night or Sunday, and tech came back out Monday. Said there may be a leak, filled it up, affixed two “pins” to the line, and said it should fix it. It didn’t. Came back out Wednesday, put a dye in it to locate a possible leak, said there wasn’t one, but that the dye also seals the leaks so it was likely fixed. Refilled it, and said it should cool down, it didn’t.

Called another company, they came out and thoroughly cleaned the unit (so now it wasn’t running as hot), and welded the line where the pins were placed, incase they weren’t sealed properly. It again never cooled down, however now the temperature display reads “HH”. I researched this and, although I could not get any information on my specific brand, it appears to be a common reading for a bad sensor.

The unit appears to be blowing cold air, and gets down as low as mid 40s / low 50s, but never any colder. My question is, if anyone may know, could a bad temperature sensor cause the unit to not cool? I would think it’s plausible that, since the unit sets the temperature, and subsequently monitors when the unit needs to run and not, that this bad sensor could cause it to just now kick on and cool to the appropriate temperature or something along those lines?

I am ignorant when it comes to refrigeration, so I have no idea if my thought holds any merit, and the techs that were out here already never mentioned it (although one said the display seemed to be inaccurate by about 10 degrees from his reading). I already have over $1,000 in “repairs”, and a still unfixed unit, so I do not want to call them back out for a random uneducated hunch, but the next step is to just purchase a new unit.

It is a Metalfrio 93" 3 door prep table, about 7 years old. Fan motor was recently replaced (5 months). Compressor I believe is original. Any advice from experience would be welcome!

I am not an expert either, but could be a clogged capillary tube. When the unit isn’t cleaned properly or has to run a lot because it is hot in the building this can cause the oil in the unit to gum up, clogging the capillary tube. The unit will kind of get cold, but not cold enough. This problem will get worse because the unit keep running because it does not get as cold as it should, compressor gets warm, more oil gumming up. We had this happen this summer. Unit was drawn down of coolant, capillary tube was replaced where clogged, refilled with coolant. Done.

this was my first thought also.

I am sure with 2 companies looking at this that this is not the problem, but are you sure that the unit is completely defrosted (evaporator not a block of ice)?

I have unfortunately learned that so are many A/C companies. Go to your local Publix and ask who they use to service their refrigeration. Or Sams Club. I’ve had much better luck with refrigeration companies as opposed to A/C oriented companies.

They never should’ve put Dye/Stop Leak in a Cap tube system. You need to get a refrigeration company, not somebody that does hvac. And while I know you don’t want to hear this, 7 years on a cheapo table is probably reaching the limit. Don’t get me wrong I use them some, but the coils and everything are thin material and they start leaking everywhere.