Low
53 on Sime Dewy 30/50 HE WM

Your boiler has disabled its automatic energy-saving features, meaning it will now run at a fixed temperature rather than adjusting itself based on the temperature inside your home.

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

Type of control: This parameter de-activates the ambient influence and as a result all the optimisations and adaptations.

From this model's manual
Verified against the Sime Dewy 30 50 He Wm installation & service manual, page 15.
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 fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.

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