Fujitsu Waterstage 11 fault code
Fujitsu Waterstage heat pumps
What the Fujitsu Waterstage 11 fault code means, from the manufacturer's own service literature, and the UK models it applies to.
What it means
Serial communication error
Source: Fujitsu Waterstage Comfort D&T Manual DA_CF001EF, §Control System pp.03-2…03-4 (official-distributor mirrors) — numeric display codes with Fujitsu's own reset and runs-despite-error columns, plus the interface-card LED table
UK models this code applies to
Tap yours to open 11 on that machine.
11 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
11 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 11 on your machine →Free, no sign-up. We don't hold a chart for this code yet — pick the model for its manual section.
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Related codes
- 10/1Discharge temperature protection
- 10/3Compressor temperature protection
- 10/4Outdoor unit pressure error
- 10/5Low pressure abnormal
- 10/9Current overload error
- 11 flashesDischarge temperature protection (permanent stoppage)
- 12 flashesCompressor temperature protection (permanent stoppage)
- 13 flashesCurrent trip (permanent stoppage)
- 14 flashesDetection of compressor position error (permanent stoppage) — 3-phase…
- 15 flashesCompressor start-up error (permanent stoppage)