Testing fan Venturi

[gassafe]

Hey guys went to a baxi 105 with flue fault & I thought it was a aps fault as it fired when I blew into the + on the aps but new one was the same.

How do you guys test the Venturi without taking all the fan out?

I attached my digital manometer to the + symbol off the fan & got a really low reading, something around 0.6 mbar!? I have since read the Venturis can melt on these?

 

[gassafe]

Just seen this online, I wish I had tried that now

 

[armourer]

we get this quite often mate. Be aware this is normally caused by flame lift which is normally the flue cross contaminating. Do a full flue inspection and telegan checks.

 

[armourer]

BTW it only takes 10 minutes to remove the fan. remove the flue clamp and two screws at the back of the flue hood and the whole thing lifts out.

 

[Billy Bob Bob]

another cause of a melted venturie is the fan relay failing or it running very,very low on water but pump switch still makes,sometimes melts before the H/L stat kicks in