Low
D.84 on Vaillant Atmomax

Your boiler is simply reminding you that a routine service is due soon based on the number of operating hours it has completed.

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.

Technical description

Maintenance indicator – number of hours until the next maintenance

DIY fix possible

Check your records to see when the boiler was last servicedBook a routine service with a Gas Safe registered engineerMonitor the boiler for normal operation until the engineer arrives

Find a Gas Safe engineer
Search the official register →

Related fault codes

S.31View →

Related guides you might find useful

Boiler keeps cutting out

Lockout fault with a reset-needed pattern.

Read →

Yellow or orange flame — CO safety

Safety-critical — turn off, read this.

Read →

Is boiler cover worth it?

Break-even maths on monthly cover.

Read →