How much does it cost to fix Atag error code b19?

Typical repair cost for the Atag b19 fault is £120-£350 including labour.

b19 High

Atag b19 Fault Code

Q: What does the Atag b19 fault code mean?

Your boiler has shut down because the water returning from your radiators has become too hot, usually due to a lack of circulation through the system.

Also written as B19 — same fault.

The Atag b19 fault code means: your boiler has shut down because the water returning from your radiators has become too hot, usually due to a lack of circulation through the system.. It appears on 1 Atag model in our database.

Technical description: Boiler block: Return temperature > 90°C

Typical repair cost £120-£350 (including labour)

DIY fix possible

Check that all radiator valves (TRVs) are turned to their highest settingEnsure the boiler pressure is between 1.0 and 1.5 bar on the gaugeCheck that the internal pump or any external zone valves are making a normal humming soundRestart the boiler using the reset button

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Atag models that show the b19 fault code

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

E Range Repair: £120-£350

Source

Atag b19 fault code information on this page is sourced and cross-checked against the official Atag service / installation manuals for each affected model.

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