Recently had a new furnace/ac/ductwork installed in our home. The furnace/air handler are located in the attic on the second floor of the home. A drain line is run from the unit to the utility room on the first floor where it feeds into a floor drain.
About a month after the system was turned on I noticed that the drain line (clear plastic flex tubing) was not draining properly. This tubing runs through a joist bay between my first and second floors (currently open due to renovation) in order to get from the attic on one side of the house to the utility room on the other side. The tubing is not run at a pitch so the water is pooling and not draining.
I asked the HVAC installer if that was a problem and he said it wasn't. I assume it IS a problem, is that correct? If the line were to be adjusted to run at a pitch, would that solve the problem? Or should it be draining currently due to negative pressure?