Walk-in Freezer Defrost Fault
- Interactive decision labs
- Built by working technicians
- Path-based verifiable certificate
- Exam preparation only
- Worldwide online
Commercial Refrigeration / RAC
~15 min
intermediate
The call
Walk-in freezer keeps icing up. Product temperature climbs a few degrees each day and the customer has been scraping the coil by hand.
- Equipment
- Walk-in freezer, R-404A, electric defrost, mechanical defrost timer, ~10 years old
- Ambient
- 78°F
- Site notes
- Box was clean-defrosted manually two days ago and held temperature for one day before drifting again.
Decision 1 of 5
The unit is running and the box is at 6°F against a -5°F setpoint. The evaporator is behind a frosted grille.
Where do you start?
Where this lab sits
This is one module lab from Commercial Refrigeration / RAC. The full path adds sealed systems, defrost, rack-system orientation and natural-refrigerant safety, each ending in a lab like this one.