High
Radiators cold in winter on Ferroli Optima 201

Your boiler is failing to circulate heat to your radiators, likely because the internal pump is stuck or the system is failing to detect the correct temperature.

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.

Technical description

Faulty flow temperature sensor. Room thermostat set too low or faulty. Pump is stuck and fails to rotate. The pump does not rotate

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

F37View →F43View →

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