vaillant vcv aps

[giarc00007]

been to above boiler no heating or hot water. pump runs, fan spins no spark. took hose of aps and sucked in tube fired up straight away. i am thinking blocked venturi but could aps still be faulty even though im forcing it to light?

 

[GrahamM]

APS itself may be faulty and not activating at its set pressure.
Fan may be slowing and too weak to activate APS at set pressure.
Or as you say a blocked venturi is the issue.

There is a way of testing the APS is operating correctly using your Analyser, syringe and meter.

I would start with cleaning venturi and fan and see how goes from there. Give fan a bit of lube and make sure APS tubes all good condition.

 

[quality]

As above cant beat a bit of lube and checking the tube

 

[giarc00007]

ok thanks guys will do.