The stove has been burning dirty despite regular cleanings and a "break down/pull the combustion motor" cleaning at the end of last year. It doesn't seem like it should be time for a cleaning so soon this year, but there it is- the stove is burning dirty. We vacuum the exhaust vent out from outside the house regularly, etc. so we thought we were getting away with not doing the Leaf Blower Trick. We didn't have a leaf blower that would work in that capacity (long story) so we tried vacuuming from the outside as an alternative. But the stove is now burning dirty despite it all. I bought a Black and Decker leaf blower this afternoon, and some PVC fittings, and I'm ready. I know that you guys disconnect the vacuum switch and/or remove the vacuum hose before the LBT. The trouble is, my manual is not overly helpful in this regard. Here are two pictures. I can take more if necessary . What do I disconnect here?