High
Neon 2 NOT lit on Glow-worm Space Saver Compleheat 30 40 50

Your boiler has switched itself off to prevent overheating because the system is getting too hot or the water is not circulating properly.

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

Control thermostat overheat or pump failure cut-off devices operated. Faulty pump.

From this model's manual
Verified against the Space Saver Complheaet 30 40 50 installation & service manual.
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 fault occurs when the water inside the boiler reaches an unsafe temperature, triggering a safety switch to shut the system down. The most common reasons are a pump that has stopped circulating water or a blockage in the pipework that prevents heat from escaping the boiler. Just like an engine overheating, the boiler stops to prevent internal damage to its components.

This issue often appears when the heating is turned back on for the first time in autumn, as pumps can seize up after being idle throughout the summer months.

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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