Medium
07 on Saunier Duval Isofast F28E

Your boiler is struggling to detect the temperature of the water it is trying to heat for your taps and shower, so it has stopped providing hot water to prevent overheating.

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed

Book a service

This fault should be looked at by a Gas Safe engineer within the next week or two. It may get worse if left.

What the manual says

Manufacturer manual

Domestic hot water thermistor/wiring fault

From this model's manual
Verified against the Saunier Duval Isofast F28e installation & service manual, page 30.
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 fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.

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