NIBE 240 fault code

What it means

Low evaporation temperature

Five repeated low-evaporation alarms within 4 hours. NIBE's listed causes: lack of refrigerant, or a blocked expansion valve.

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

240 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.