NIBE 238 fault code
NIBE heat pumps
What it means
Hot gas alarm
Three repeated high-discharge alarms within 4 hours. NIBE's own listed causes: disruption in the refrigerant circuit, or lack of refrigerant.
Safety: R290 is A3 flammable — no ignition sources, ventilate, R290-rated equipment only for any refrigerant-side work.
UK models this code applies to
From the NIBE service literature we hold (NIBE S2125 installer manual IHB EN 2442-3 731742 — Alarm list) — not a scraped list.
Now the harder half: proving what caused it
238 names a symptom, not a root cause. In the app, the same code opens a guided investigation: what to measure first, the expected values for your exact model, and an honest verdict — including “nothing in this machine is broken” when that's what the readings say.
Chase 238 on your machine →Free, no sign-up. Pick the model and follow NIBE's own chart for it, one question at a time.
Or watch one get chased — free demo →