What does the Baxi H.01 – .21 fault code mean?

Your boiler is heating up much too quickly and has shut itself down to prevent damage, likely because the water isn't moving through the system fast enough.

How much does it cost to fix Baxi error code H.01 – .21?

Typical repair cost for the Baxi H.01 – .21 fault is £120-280 including labour.

Can I fix Baxi fault code H.01 – .21 myself?

Check that all radiator valves and any isolation valves are fully open

Baxi H.01 – .21 Fault Code: What It Means & How to Fix It

Technical description

Temporary error – flow temperature increasing too fast in domestic hot water (DHW) mode, insufficient circulation or sensor error.

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.

Find a Gas Safe engineer

Search the official register →

Related fault codes

E110View →

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Your boiler is heating up much too quickly and has shut itself down to prevent damage, likely because the water isn't moving through the system fast enough.

Technical description

Engineer required

Related fault codes

Related guides you might find useful

No hot water but heating works

Banging / kettling / whistling noise

Radiators cold at the bottom

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