Ariston · Clas ONE
501 boiler fault code
Clas ONE
Get a Gas Safe engineer
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What 501 means
501 indicates that no flame was detected.
Safe check
Follow the user manual to reset once only. Do not repeat the reset.
When to contact an engineer
The code remains or returns after one reset; arrange a Gas Safe registered engineer.
Safety notice
A boiler fault code alone is not a gas or carbon-monoxide emergency. If you smell gas, a CO alarm sounds, anyone feels unwell, or there is an unsafe flame, leave and call 0800 111 999 from outside.
Source and provenance
- Clas ONE and Clas System ONE User Manual GB/IE · p. 9
user manual
Clas ONE UK user manual
Renting? Report it to your landlord or housing provider first. They are responsible for gas safety and boiler repairs, and the repair should not cost you.
Did this fix it?
After: Reset the boiler once