Jianaihua

When a customer reports a problem with their convenience store freezer to after-sales service, a repair technician will schedule a timely on-site repair. Upon receiving the freezer, the technician will first inspect the exterior for dents, paint chips, and the number of drawers. Any issues should be pointed out to the customer to avoid future disputes about repair work.

The testing steps are as follows: First, open the compressor cover and test the machine. If the compressor runs normally, touch the high-pressure outlet temperature to roughly determine if there is a refrigerant shortage. Stop the machine and wait a few minutes until the high and low pressures are roughly balanced. Then, use a refrigerant cutter to cut open the pipes and assess the amount of refrigerant discharged to determine if there is a refrigerant shortage. After starting the system, it's crucial to check the compressor discharge first. Otherwise, repairing the pipes and finding a problem with the compressor will cause further issues. (You can disconnect the capillary tube at the filter, then block the filter outlet by hand, turn on the machine, and judge the compressor's discharge capacity based on the pressure and discharge volume.) This can also remove any residual refrigerant from the pipes.

The above is a preliminary assessment. Then, you can perform segmented pressure testing to confirm the results with data. Some machines, once a refrigerant deficiency is detected, don't require pressurization at all. Only by replacing both the high and low pressure systems can a problem be solved. For example, in a multi-door freezer older than 5 years, if the refrigeration pipes are made of iron, even if the high pressure leaks, the low pressure won't be maintained for long. If the low pressure leaks, you'll see rust on the door frame; even if the low pressure is repaired, the high pressure won't be maintained for long either.

For such machines, it's best to repair both high and low pressure systems simultaneously. Otherwise, problems are likely to occur in a short time, leading to repairs. Although it's not our fault, customers may not understand, which can significantly damage our reputation. The above analysis applies to mechanically controlled single-system freezers where the compressor is functioning normally but not cooling.

Finally, you must explain to the customer why the freezer isn't cooling, where the problem lies, what parts need to be replaced, and the repair costs. All these details must be clearly explained to the customer. Repairs should only begin after the customer agrees.