High
F.93 on Vaillant ecoTEC plus 938 VUI 286/5-5 R6

Your boiler has detected an internal configuration error, meaning the main control board and gas valve settings do not match correctly.

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed

Call an engineer soon

Book a Gas Safe engineer within 24 to 48 hours. Your boiler may be unsafe or could break down completely if left.

What the manual says

Manufacturer manual

See the table of fault codes in the appendix

From this model's manual
Verified against the Vaillant/Vaillant Ecotec Plus 938 Vui 286 5 5 Isim installation & service manual.
Plain-English guidance below. Severity, DIY steps, costs and parts are our interpretation to help you act, not text from the manual.

Engineer required

This is a high severity fault. Stop using the boiler and call a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.

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Related fault codes

F.91View →F.92View →F.94View →

All 59 fault codes on the ecoTEC plus 938 VUI 286/5-5 R6

Seeing a different code? Every code this model can display, in one place.

F.00F.01F.02F.03F.10F.11F.12F.13F.20F.22F.23F.24F.25F.26F.27F.28F.29F.32F.42F.49F.52F.53F.54F.55F.56F.57F.61F.62F.63F.64F.65F.67F.68F.70F.71F.72F.73F.74F.75F.77F.78F.80F.81F.82F.83F.84F.85F.90F.91F.92F.94S.88S.92S.93S.96S.97S.98S.99

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