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S.31 on Glow-worm Ultracom 35 Store

Your boiler is currently set to provide hot water only, and the central heating has been disabled because it is in summer mode.

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

summer mode

From this model's manual
Verified against the Glow Worm Ultracom 2 Cxi installation & service manual, page 52.
Plain-English guidance below. Severity, DIY steps, costs and parts are our interpretation to help you act, not text from the manual.

What causes this fault?

This status occurs because the central heating function has been manually switched off, leaving only the hot water operational. It is usually caused by the user or an engineer adjusting the control dial or digital settings to a 'hot water only' position. There is no actual mechanical fault with the boiler; it is simply following the instruction to ignore calls for heating.

This is most common during the spring and summer months when homeowners intentionally deactivate their heating to save energy.

DIY fix possible

Locate the temperature control knob or buttons for the central heating on the control panel.Increase the heating temperature setting or turn the dial clockwise to exit summer mode.Ensure your room thermostat or programmer is also calling for heat.

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