When a walk-in will not hold temperature
Warm product usually comes from a short list: a door that does not seal, a coil packed with dirt or ice, a fan that has stopped, a metering device that is not holding, a leak, or a control reading the wrong location. The diagnosis starts there, rather than with a recommendation to replace the system on the first visit.
If the walk-in itself has failed — floor rot, panels that sweat, or a ceiling that will not support another evaporator — it is replaced, and the refrigeration is matched to the new room rather than to the old equipment.