High
F59 on Viessmann Vitopend 100

Your boiler has lost the signal from the sensor that monitors your hot water temperature, so it has stopped heating water to prevent the system from overheating.

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

No DHW heating Lead break, outlet temperature sensor (gas combi boiler)

From this model's manual
Verified against the Viessmann Vitopend 100 installation & service manual, page 38.
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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