Boiler Fans

[newcomers]

Had a job today for work to change a fan on a vaillant (somebody else had booked the job up)

I got there, and the fan was running fine, but wouldnt go to ignition. I blew on the air pressure switch and it then went to ignition. I thought it must be the air pressure switch, but as it was a very experienced who booked the job, I went ahead and changed the fan. With the replacement fan, it then worked.

My question is, in this situation I wouldve gone for the air pressure switch. How can you first eliminate the fan before going for the air pressure switch?

Thanks

 

[corgiman]

i would check the silicon tubing first matey make sure its sound if it is then probably a new aps

 

[newcomers]

i would check the silicon tubing first matey make sure its sound if it is then probably a new aps

But in general I mean, how would you eliminate the fan being at fault and not the aps?

As it happens, when I took the old fan off, all the inside was burnt out where the air inlet for the aps connects, and was stopping airflow to the aps.

Its just that if that was me on that job as a breakdown, I wouldve booked up a new aps and not the fan. I forgot to ask the other guy what made him go for the fan, and how he came to that conclusion

 

[bab]

Also look out for restricters in aps tubing that block Prima F,s etc.

 

[ollski]

Stick your pressure tester on the fan venturii to see if its pushing out enough to make the aps which will have the pressure written on the side.

 

[corgiman]

good point also check venturis

specaiily on halsteads

spit

 

[Gasguru]

Check venturi's and pitot tubes (recent turbomax's have both on the fan) and correct flue restrictors. Spent over an hour on hold to Vaillant yesterday obtaining the correct restrictor part number. The Turbomax Plus's are very sensitive (cos someone decided to design the ignition pressure to be the same as the minimum rate)

 

[ollski]

Isn't it the turbomax / plus that has famously rubbish aps?, the black one now replaced with a huba on the top right at the back. I would change it anyway even if it was the fan which was at fault.

 

[Agile]

No mention of the boiler model !

With experience one knows the most likely cause of faults on particular models.

Some APSs are known to fail and some dont!

Tony