We have a new Goodman GMH950904CX that was just installed. It is installed in the basement for upflow. When the HVAC tech installed the furnace, the furnace was tilted slight to the front which is correct, but the furnace is not level with left side higher than the right side.
The tech used the drain hole on the left side. The furnace would stop after 5 minutes. I changed the drain tube to the right drain hole and now the furnace would operate for at least 15 minutes. The weird thing is that it would shut off intermittently and flash 3 diagnostic flashes and would not restart. Turning off the unit and powering back on it would run for another 15+ minutes.
I checked the drain and there is no back flow or clog in drain. The exhaust pipe is draining fine and the 2nd heat exchanger is draining fine. I left the front cover off and this still happens so most likely not a fresh air supply problem.
I am stuck!
Does anyone have any suggestion? Could a new furnace have a bad pressure switch? Is that common? Also, the furnace was in the basement for about 3 months during construction. Would the dust have possibly clogged up something in the furnace? or clogged up the pressure switch?