Medium
d.50 on Vaillant ecoTEC plus aquaPLUS

Your boiler has reached its maximum allowed internal temperature and is pausing operation to prevent damage.

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed

Book a service

This fault should be looked at by a Gas Safe engineer within the next week or two. It may get worse if left.

What the manual says

Manufacturer manual

Maximum flow temperature

From this model's manual
Verified against the Vaillant Ecotec Plus Aquaplus 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.

DIY fix possible

Check that all radiator valves (TRVs) are fully openEnsure the central heating system pressure is between 1.0 and 1.5 barTurn the heating control knob down slightly and reset the boiler

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