High
E19 on Keston System S40

Your boiler has likely stopped working because the water returning to the unit is too hot, which happens when water isn't flowing through your radiators properly.

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

Maximum return temperature exceeded – check circulation

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

E18View →

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