Fujitsu Waterstage 3 flashes fault code
Fujitsu Waterstage heat pumps
What the Fujitsu Waterstage 3 flashes fault code means, from the manufacturer's own service literature, and the UK models it applies to.
What it means
Pressure sensor error
Source: Fujitsu Waterstage Super High Power D&T Manual, §Control System pp.03-3…03-5 — numeric display codes, interface-card LED pairs and outdoor-board flash counts with the published decode procedure
UK models this code applies to
3 flashes 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
3 flashes 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 3 flashes on your machine →Free, no sign-up. We don't hold a chart for this code yet — pick the model for its manual section.
Or watch one get chased — free demo →Related codes
- 1 flashSerial forward transfer error
- 1/1Communication error between hydraulic unit and outdoor unit
- 2 flashesDischarge thermistor error
- 2/3Connection forbidden (series error)
- 3/1Indoor unit power supply abnormal
- 3/2Serial communication error between controller PCB and interface PCB
- 4 flashesHeat-exchange thermistor (outlet) error
- 4/1Heat pump capacity signal error (open or short)
- 4/2Hydraulic indoor unit heat exchanger thermistor error
- 6 flashesExpansion valve thermistor error