S.02
FAULT CODE
Vaillant
DHW Demand Active
Low Severity
DIY Check Possible
A status code showing the boiler is actively heating domestic hot water. Not a fault — purely informational.
Step-by-Step Fix Guide
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Step 1
No action required — this is normal operation
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Step 2
Heating will resume after the DHW demand is satisfied
Gas Safe Reminder
Work on gas appliances must be carried out by a Gas Safe registered engineer. The steps above cover safe checks a homeowner can perform - any internal component replacement requires a qualified professional. If in doubt, always call an engineer.