Inverter Mini-Split (R-32) Will Not Pull the Room Down
“The head runs all the time but the office sits at 28°C. It was fine last summer.” Unit: Single-zone inverter mini-split, R-32, 12,000 BTU wall head, 9 m line set with an outdoor unit on a flat roof. This is one of three free graded decision labs from Residential HVAC Service & Diagnostics — 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: 230 V 1-phase · 50 Hz · SANS 10142-1. Working temperatures on this track are °C.
The call
“The head runs all the time but the office sits at 28°C. It was fine last summer.”
- Equipment
- Single-zone inverter mini-split, R-32, 12,000 BTU wall head, 9 m line set with an outdoor unit on a flat roof
- Ambient
- 99°F
- Site notes
- Head is running at a low fan speed and never ramps. Outdoor unit is against a parapet wall with about 100 mm of clearance. Error history has not been read.
Decision 1 of 4
The wall head is running at a low fan speed and never ramps up. The office sits at 28°C on a very hot afternoon.
Where do you start on an inverter system?
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 Residential HVAC Service & Diagnostics. 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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