In message , Sparks writes
Hi,

I have a Potterton Profile boiler in a fully pumped system.

The boiler's pilot light is lit every time the boiler is needed.
automatically

I have noticed recently, when the boiler is called for, it sometimes
(usually) does the following

Fan on (5 seconds)
Fan off 3 seconds

Fan on 2 seconds
Fan off 3 seconds

The 2on 3off can repeat for a while (8 times just now when I tested it from
cold)

Then it ignites, and works fine (as far as I can tell!)

About a minute after it was running, I turned it off, then back on again, it
did the 2on 3off 4 times this time

Is this something I should worry about?!

If so, what is the likely problem?


I would think it's the air pressure switch on it's way out or a relay on
the pcb
--
geoff