High
28 on Ideal Maximiser SE 42

Your boiler is not receiving a steady supply of gas or has air trapped in the pipes, preventng the flame from lighting properly.

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed

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

The burner is supplied with too little gas or air is present in the gas pipe; check the pre-pressure. If the control pipe is not blocked, the gas/air ∆P should be checked at minimum and maximum load.

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 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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All 40 fault codes on the Maximiser SE 42

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

- / A- / H- / Y= / H4 / A111213141516171819202122232425262729303132333435363738394041424344E / F

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