Emergency
F.20 on Vaillant ecoTEC plus 937

Your boiler has detected that it is running too hot and has automatically shut down to prevent any damage or danger.

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed

Act immediately

Turn off your boiler and stop using gas appliances. Call a Gas Safe engineer now. This fault can be dangerous if ignored.

What the manual says

Manufacturer manual

Safety temperature limiter by NTC activated - Flow probe not connected thermally correct or defective, appliance does not shut down

From this model's manual
Verified against the Vaillant/Vaillant Ecotec Plus 937 Vui Gb 376 3 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 emergency 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.22View →F.23View →F.24View →

All 38 fault codes on the ecoTEC plus 937

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

conF.0F.01F.02F.03F.10F.11F.12F.13F.22F.23F.24F.25F.27F.28F.29F.32F.49F.61F.62F.63F.64F.65F.67F.70F.71F.72F.73F.74F.75F.76F.77F.78F.80F.81F.90F.91

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