H20-986 Medium

Ideal H20-986 Fault Code

Also written as H20986 — same fault.

The Ideal H20-986 fault code means: your boiler has detected trapped air inside the system, which is preventing water from circulating correctly to provide you with heating and hot water.. It appears on 6 Ideal models in our database.

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.

Technical description: Automatic air purger valve
Typical repair cost £120-200 (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 H20-986 fault code

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

Source

Ideal H20-986 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