Ariston · Clas ONE
108 boiler fault code
Clas ONE
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What 108 means
108 indicates insufficient water pressure.
Safe check
Use the filling loop to raise pressure to 1 bar, then allow the PURGE cycle to run as described in the user manual.
When to contact an engineer
The pressure fault occurs frequently, pressure will not hold, or the code remains after following the manual; contact an Ariston technician or 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: Repressurise the boiler