This is my first post, I hope I can get some answers here.
About a week ago, I had a 90% efficiency furnace installed in my attic. It vents horizontally through the sidewall of the house.
I am very pleased with the contractor and his installation, but I saw one thing that confused me. The vent coming out of the furnace is 2", so the contractor installed a short 2" PVC pipe, then a 2" to 3" transition, and then a 3" PVC pipe which goes to the outside.
The vent pipe is pitched towards the furnace, as the contractor explained to make any condensate drain towards the furnace and out the drain system. But looking at the horizontal vent pipe, it appears to me that the 2" to 3" transition essentially creates a "step" that the condensate cannot go over, so there will always be a small puddle remaining at the 2" to 3" transition.
I know it's hard to explain this, but hopefully you can visualize this "step" at the transition.
My contractor says it's nothing to worry about - would you agree?
Thanks in advance.