I was working on a water source heat pump today. The incoming water is from the city and the outgoing water goes down the drain. The condensate drain ties into the water out line. I always thought that you have to run both drain lines separately because you can not vent the drain pan line properly.
The drain pan line just tied into the discharge line and would overflow the the drain pan when the water regulator would come on. I dont understand how this ran for 4 years...... Or did it just short cycle on the water sensing probe ( like it was today )
I'm going back tomorrow to run two lines but another tech told me to just install a check valve between the trap outlet and the branch of the tee. I always thought that you are not supposed to install check valves on gravity drains.
Any opinions on this and or pics ( if you tie them together )