How much does it cost to fix Vaillant error code Er.1?

Typical repair cost for the Vaillant Er.1 fault is £120-250 including labour.

Er.1 High

Vaillant Er.1 Fault Code

Q: What does the Vaillant Er.1 fault code mean?

Your boiler has failed to ignite the gas needed to heat your home, which has triggered a safety shutdown.

Also written as ER1 — same fault.

The Vaillant Er.1 fault code means: your boiler has failed to ignite the gas needed to heat your home, which has triggered a safety shutdown.. It appears on 2 Vaillant models in our database.

Technical description: Burner, natural gas (Burner chamber group / Distributor tube)

Typical repair cost £120-250 (including labour)

Engineer required

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

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Vaillant models that show the Er.1 fault code

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

Source

Vaillant Er.1 fault code information on this page is sourced and cross-checked against the official Vaillant service / installation manuals for each affected model.

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