Low
S.22 on Vaillant ecoTEC plus System

Your boiler is simply preparing its internal pump to begin heating your hot water, which is a normal part of its startup sequence.

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed

Monitor it

This is a minor fault. Keep an eye on it and mention it at your next annual boiler service. Reset the boiler and see if it clears.

Technical description

Hot water handling mode: Pump pre-run

Engineer required

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

Find a Gas Safe engineer
Search the official register →

Related fault codes

S.20View →S.21View →S.23View →

Related guides you might find useful

No hot water but heating works

Almost always a stuck diverter valve on combis.

Read →

Banging / kettling / whistling noise

Each noise points to a different fault.

Read →

Is boiler cover worth it?

Break-even maths on monthly cover.

Read →