Hitachi 00501 fault code

What it means

Overload protection has cut the compressor at its lower operating limit — the unit is running against an overload condition.

Safety: Safe isolation before disconnecting the compressor or testing the inverter board — capacitors hold charge.

Source: Hitachi Technical Catalogue §9.10 / §10.1.2 Error Code Information (RAK-PSES(W)/RAC-WSE — Hitachi UK; RAK-PED/RAC-WED — Hitachi R32 catalogue), both render-verified

UK models this code applies to

Tap yours to open 00501 on that machine.

00501 on these comes from each model's own manual, which may not match the meaning above — tap yours to read it.

Now the harder half: proving what caused it

00501 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: where we hold a chart for it, it takes you through one question at a time.

Or use it in your browser on any phone or laptop.