Medium
- / H on Ideal Maximiser SE 42

Your boiler is able to heat your hot water, but it is struggling to produce enough heat for your radiators because it cannot switch to full power.

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed

Book a service

This fault should be looked at by a Gas Safe engineer within the next week or two. It may get worse if left.

What the manual says

Manufacturer manual

The central heating installation is not sufficiently heated, the hot water tank (if present) is correctly heated. On the central heating side the unit can only be fired at low power.

From this model's manual
Verified against the Ideal/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.

Engineer required

This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.

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All 40 fault codes on the Maximiser SE 42

Seeing a different code? Every code this model can display, in one place.

- / A- / Y= / H4 / A11121314151617181920212223242526272829303132333435363738394041424344E / F

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