Low
i22 on Worcester Bosch Greenstar Heatslave II

Your boiler is displaying a specific tracking code that identifies its power configuration, which usually appears after an internal control module has been replaced or reset.

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed

Monitor it

This is a minor fault. Keep an eye on it and mention it at your next annual boiler service. Reset the boiler and see if it clears.

Technical description

HCM number - HCM last 3 digits displayed: 391 = 12/18 kW, 390 = 18/25 kW, 301 = 25/32 kW

Engineer required

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

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Related fault codes

i21View →i23View →

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