High
59 on Sime Dewy 30/130 HE FS

Your boiler has detected that the water temperature is rising or falling too quickly, causing it to shut down to protect itself from potential 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

Heating gradient

From this model's manual
Verified against the Sime Dewy 30 130 He Fs installation & service manual, page 17.
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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