Mitsubishi Ecodan P8 fault code

What it means

Refrigerant circuit abnormality

Detected from pipe-temperature relationships (manual: TH6–THW2 ≤ 1 °C / TH7–TH3 ≤ 1 °C at ≥ 61 Hz) — refrigerant not doing what the mode demands.

Safety: R32/R290 (model-dependent): flammable refrigerant — leak-check with suitable equipment and ventilate.

How to read it — ftc controller: Ecodan check codes show on the FTC / main controller display. (Ecodan service manual OCH727, §9-2 self-diagnosis action table)

UK models this code applies to

From the Mitsubishi Electric service literature we hold (Ecodan service manual OCH727 §9-2) — not a scraped list.

Now the harder half: proving what caused it

P8 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.

Free, no sign-up. Pick the model and follow Mitsubishi Ecodan's own chart for it, one question at a time.