Medium
d.50 on Vaillant 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

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

Technical description

Maximum flow temperature

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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Related fault codes

F.20View →F.22View →F.24View →

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