Grant Aerona E10 fault code

What it means

Hydraulic ↔ refrigerant PCB communication failure

The two boards have stopped talking: communication cable, then either PCB.

Safety: Safe isolation before opening terminal covers — mains present on the interconnect.

UK models this code applies to

From the Grant service literature we hold (Grant Aerona 290 installation manual DOC0204 Rev 1.8, Table 11-1) — not a scraped list.

Now the harder half: proving what caused it

E10 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 Grant Aerona's own chart for it, one question at a time.