I have a Lennox high efficiency furnace the vents out the roof with plastic piping, both fresh air and exhaust. The fresh air pipe terminates above the roof with a U-shaped pipe at the end of it, I presume to keep out moisture. The exhaust pipe on the other hand just terminates with an open pipe facing skyward.
The problem we have is moisture and insects hit the open end , runs down inside the pipe until it collects in the exhaust blower in the furnace . We have to have a serviceman out approx. every 4 months to unclog the drains , and remove water from the blower.
Can we put a raincap or u-shaped piping on the end of the exhaust pipe? The serviceman says its just a problem with these furnaces that vent thru the roof.