Insurance replaced our Suburban furnace due to a water leak that they were afraid water leaked into a floor vent and down into furnace itself. Abundance of caution here. Husband says he is gonna upgrade the 35 to the 42. Repair tech says it isn’t a problem. Installed for a year now and haven’t used it much but we noticed a difference in air flow. Had a tech come out (not the same one) just to make sure that everything was okay. 2018 MS 41RSSB4 has two vents in LR on off door side on one of the ducts. On the door side there is a total of 5 vents, one in BD, BR, and 3 in kitchen/LR on 2nd duct. When furnace comes on the flow is out of the 2 vents on the off door duct side. The flow to the 5 vents on door side is very little. We have been told it is because the bigger motor now just sends the air the path of least resistance in the strait duct to the 2 vents and is kind of by passing the duct with a bend due to force. They say we can’t switch the ducts. can anyone help me understand this better? I would think more flow that both ducts would get more, not one more and one less? Do I switch back to a 35 at a 1k cost?