High
2P on Ideal Maximiser SE

Your boiler is overheating because the water inside it is getting too hot too quickly, causing the system to shut down for safety.

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

Temperature of safety sensor is rising too fast.

From this model's manual
Verified against the Ideal Maximiser Se 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 heats up much faster than it can be moved away, leading to a sudden temperature spike that triggers a safety shutdown. The most common cause is a blockage or a failing pump preventing the water from circulating properly through your radiators. It can also be caused by a buildup of sludge or debris inside the heat exchanger, which restricts the flow of water.

This issue often surfaces in autumn when the heating is turned on for the first time after summer, as circulation pumps can seize or stick during long periods of inactivity.

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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Avoid the next call-out bill

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