Low
P.5 on Vaillant ecoTEC

Your boiler is currently running a mandatory internal safety test to ensure it can shut down correctly if it gets too hot.

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.

What the manual says

Manufacturer manual

Test program for the safety temperature limit check; appliance heats up by by-passing a regulating shutdown through the flow regulator until the shutoff temperature of 97 °C is achieved.

From this model's manual
Verified against the Vaillant Ecotec installation & service manual.
Plain-English guidance below. Severity, DIY steps, costs and parts are our interpretation to help you act, not text from the manual.

Engineer required

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

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