Gremlins in an Ariston Microgenus

[Billiam]

Any ideas ?
My Micrigenus 23Mffi fires up, when on either Hot Water or C/Heat mode, then dies after 10 secs.
( the red LED comes on)

Water pressure fine.
Water pump activates.
Fan activates.
Gas fires up.
Can see the ignition spark ' asparking'
The Flame safety device in the flame appears fine.
All's well... for 10 seconds at a a time. But it shuts down totally.

Overheat sensor repaced.
Water temp pobe replaced.
( the easy bits first ! )
Checked all visible terminals.

Just to add insult to injury, the gremlin will go away, and the boiler works perfectly.... C/H or H/Water.
Until...

Three weeks later, same thing .

No good me calling out an engineer to a working boiler, so...
Any ideas ?
Bill

 

[Danthegasman]

If I remember rightly sometimes the flue restrictor can cause problems in this boiler. Make sure the right ones installed or remove it.

 

[Billiam]

Thanks.
I'll check that. Meanwhile, the gremlin has left ....
Next time . I guess it will be a call- out to run thro the system... I'm just trying to see if there is a simple cure. (The sensors were only £3 50 )
Keep well, Bill