Medium
F7 on Saunier Duval Thema F 30 E Plus

Your boiler is struggling to accurately detect the temperature of your hot water supply, so it has safely stopped heating the water to prevent it from getting too hot.

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.

Technical description

Domestic hot water thermistor fault

Engineer required

This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.

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