Walk-in Cooler Not Holding Temperature
Walk-in cooler is running but product temperature is rising. Box is at 48°F, setpoint 35°F. Unit: Walk-in cooler, R-404A, remote condensing unit, electric defrost, ~8 years old. This is one of three free graded decision labs from Commercial Refrigeration / RAC — you choose each next check, readings fill in as you work, wrong turns are coached, and you are scored on cause, efficiency, safety and verification. No login required, about 15 minutes.
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Nameplate: 400 V 3-phase · 50 Hz · AS/NZS 3000. Working temperatures on this track are °C.
The call
Walk-in cooler is running but product temperature is rising. Box is at 9 °C, setpoint 2 °C.
- Equipment
- Walk-in cooler, R-404A, remote condensing unit, electric defrost, ~8 years old
- Ambient
- 33 °C
- Site notes
- Door closes properly. No recent service. Product is warm but not spoiled yet.
Decision 1 of 5
You are standing in front of the box. The condensing unit is audibly running.
What do you check first?
This is one of three free labs
Three free diagnostic labs. HVAC Technical Training — Paths A–D unlocks the remaining labs, lessons, full exam banks, timed mocks, and the Academy certificate. We do not issue EPA 608 or NATE credentials.
90 days of graded labs and mocks from enrolment. Your Academy certificate stays verifiable after that. Official exam fees are paid to the issuing body, not us. Access is not a licence and not lifetime.
Where this lab sits
This is one module lab from Commercial Refrigeration / RAC. The full path builds the rest of the diagnostic sequence around it, each module ending in a graded lab like this one.
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Free practice questions with explained answers, then come back to the labs. Exam preparation only — we do not issue EPA, NATE or other official credentials.
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