S.30
FAULT CODE
Vaillant
Room Thermostat Blocking Heat Demand
Low Severity
DIY Check Possible
Status code: The external room thermostat is blocking heating mode — the room has reached the set temperature. This is normal behaviour when the thermostat is satisfied.
Step-by-Step Fix Guide
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Step 1
No action required — normal thermostat operation
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Step 2
If heating is not reaching the desired temperature, check the room thermostat setting
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.