LED2 on PCB 37 High

Ideal LED2 on PCB 37 Fault Code

Also written as LED2ONPCB37 — same fault.

The Ideal LED2 on PCB 37 fault code means: your boiler is trying to light but the flame is cutting out almost immediately, which is usually caused by a dirty sensor or a problem with the gas supply.. It appears on 1 Ideal model in our database.

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.

Technical description: Goes off during an ignition trial period.

What causes the Ideal LED2 on PCB 37 fault?

This fault occurs when the boiler's control system fails to detect a stable flame after it attempts to light. The most common reason is a coating of carbon or dirt on the sensing probe which prevents it from 'seeing' the fire, or a restriction in the gas supply preventing a strong enough flame from forming.

This issue can be more frequent during the first cold snap of autumn when debris has settled on the electrodes after a summer of inactivity.

Typical repair cost £120-280 (including labour)

Engineer required

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

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Ideal models that show the LED2 on PCB 37 fault code

Click a model for the full fault code list and model-specific repair notes.

Source

Ideal LED2 on PCB 37 fault code information on this page is sourced and cross-checked against the official Ideal service / installation manuals for each affected model.

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed 27 April 2026