I just had my entire system replaced, compressor, furnace, coil, etc... I turned it on last Friday and it was running fine all weekend. Last night I got home from work and noticed it was very hot... I went up to the attic and the drainpan was full of water.
This morning the tech came out and checked the drain lines. There was a cap on top of the main pvc drain line at the furnace. When he unscrews it the water starts draining down the pipe properly. He said it was really weird and that it should work with the cap on.
When I look at the coil there are two pvc pipes. Both of them have a vent coming up. One of them is the main drain with a p catch that overflows into the drainpan. I am not sure where the other goes but it has a vent as well that the tech said should not have the cap on it.
The tech left the cap off for now but was at a loss as to why it is doing this. Does anyone have any clues or somewhere I could point them when they come back later in the week? I would tell them to leave it with the cap off but when it is not on and the air is running it feels like I am losing alot of air out of the vent.
Thanks in advance for any help or pointers.