A walk-in cooler held product the first night, then was fixed for good
A restaurant kitchen in Monroe called on a September afternoon with its walk-in cooler losing temperature. The box was holding 42°F that night, nothing was thrown out, and after a complete repair it now cycles at 37°F.
- Same dayTechnician on site the afternoon of the call
- 42°F → 37°FHolding the first night; cycling now, below the 41°F food-safety line
- 8 lbR-404A, logged to the pound; no product thrown out
The challenge
For a pizza kitchen, the walk-in cooler is the inventory. Dough, cheese, produce and meat for the whole week sit in one box, and food held cold has to stay at 41°F or below under the FDA Food Code. On the afternoon of September 1, 2026, the walk-in at this Monroe restaurant was not holding temperature. The system runs on R-404A with a condensing unit outside and an evaporator coil in the ceiling of the box.
The kitchen had two problems at once. The short-term problem was the product: if the box crossed the food-safety line and stayed there, food would have to be thrown out. The long-term problem was the cause: a cooler that loses temperature once will do it again unless someone finds out why. A fast fix that only solved the first problem would have meant another emergency call within days.
What we did
1. Get the box cold tonight
Carson Jensen was on site the same afternoon. He found the condensing unit short cycling, checked the liquid-line solenoid valve, and found the system low on refrigerant. He added a pound of R-404A and stayed until the box was down to 42°F. That was enough to keep the product safe overnight while the real cause was found. He did not replace parts on a guess.
2. Prove the leak before replacing anything
The next day the system had lost about half a pound overnight. That confirmed a leak and gave a rate. Carson pressurized the system and found the leak in the evaporator coil. A coil replacement is a real expense for a restaurant, so the kitchen saw the evidence before it saw the quote. The customer approved the coil replacement.
3. Do the whole repair while the system is open
Yosef Moflehi removed the old coil from the ceiling of the box and installed a new evaporator coil with a new medium-temperature expansion valve, a new low-pressure switch, a new liquid-line filter drier and a sight glass. He reinstalled the temperature control and repaired the solenoid. Then he leak tested the system, pulled a vacuum to 500 microns, and weighed in a 7 lb charge of R-404A.
Replacing the valve, drier and switch with the coil costs little extra while the system is already open, and it removes the parts most likely to cause the next call. Pulling a deep vacuum removes the moisture and air that shorten the life of a refrigeration system.
While he was there, Yosef told the manager something the kitchen had not asked about: the back room around the condensing unit was running hot because the kitchen's air conditioner was not working right. Heat around a condensing unit makes it work harder, so that note was part of protecting the repair.
4. Own the callback
Five days later the new coil iced up. The low-pressure control had failed and was keeping the compressor running during pump-down. Yosef replaced it with a 5 to 20 psi control, then came back the next day to set the temperature control differential. Both return visits were at no charge. The box now cycles at 37°F.
Results
- No product lost. The box held 42°F the first night and has cycled at 37°F since the repair, below the 41°F food-safety line.
- A repaired system, not a patched one. New coil, expansion valve, drier, sight glass and pressure control, a 500-micron vacuum and a weighed charge.
- Every pound accounted for. 8 lb of R-404A in total, logged to the pound across the visits.
- A straight answer on the callback. When the pump-down control failed, the team came back twice and charged nothing.
Worth knowing
On a walk-in, prove the leak before you replace the part, and do the whole repair while the system is open. At start-up, check the pump-down control and the temperature differential, because that is where this one came back. The best service contracts set a written emergency response time and record the readings at every visit; this job got the box cold the first night, logged the refrigerant to the pound, and recorded the box temperature on the way out.
Sources: FDA Food Code 2022 (cold holding at 41°F or below); ENERGY STAR and EPA guidelines for operations and maintenance service contracts (response times and documented readings). From the AHS service records for this job.