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S.08 on Glow-worm Flexicom hx

Your boiler is taking a short, programmed break to prevent it from turning on and off too frequently, which protects the internal parts from unnecessary wear.

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

Anti cycling period

From this model's manual
Verified against the Glow Worm Flexicom 18sx installation & service manual, page 47.
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 occurs when your boiler has reached its target temperature and shuts down briefly to prevent it from 'ping-ponging' on and off. It is triggered because the heat being produced is currently greater than what your radiators can dissipate, so the system pauses to let the water cool slightly. This protects the internal components from excessive wear and tear caused by frequent starting and stopping.

This is more common during the autumn and spring when the weather is milder and your home requires less heat to stay warm.

DIY fix possible

Wait 5 to 15 minutes for the countdown timer to finish naturallyCheck that your room thermostat is turned up higher than the current room temperatureEnsure radiator valves are open to allow heat to move away from the boiler

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