Low
II - on Worcester Bosch Greenstar i

Your boiler is performing a routine initial safety check to fill its internal drainage system after the power was recently switched off.

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.

What the manual says

Manufacturer manual

Boiler running for 15 minutes at minimum heating output to fill the condensate trap (alternates with central heating flow temperature). This occurs if the mains supply has been interrupted.

From this model's manual
Verified against the Worcester Bosch/Worcester Bosch Greenstar I installation & service manual.
Plain-English guidance below. Severity, DIY steps, costs and parts are our interpretation to help you act, not text from the manual.

DIY fix possible

Wait for 15 minutes for the cycle to complete automaticallyEnsure your heating or hot water controls are set to 'on'The code will disappear and be replaced by the temperature once finished

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Related fault codes

H11View →

All 79 fault codes on the Greenstar i

Seeing a different code? Every code this model can display, in one place.

0.09U 233200201202203204208226235265268270283284305328356357358360363A1 281A7A7 808A8A8 361ACB1b7 257C1 / 264C4 / 273C4 237C6C6 / 215C6 / 216C7 / 214C7 / 217CC 800Condensate pump failedD4 341E2 / 222E2 / 223E2 / 350E2 / 351E9E9 / 276E9 224EAEA / 227EA 227EA 229EA 261EH 258F0 238F0 239F0 258F0 262F0 272F0 280F0 290F1 259F1 263F7F7 228FA / 306FA 306FdFd / 231H03H08H09H11H13h13/H13H29internal errort -

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