High
204 on Worcester Bosch Greenstar 2000

Your boiler has detected that the water inside the unit is getting too hot, so it has safely shut itself down to prevent damage.

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

Current prim. water temp. higher than set val. The actual boiler water temperature is higher than the target boiler water temperature.

From this model's manual
Verified against the Worcester Bosch Greenstar 27cdi installation & service manual, page 79.
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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