Brand new Goodman GMH950904CX runs for 10 minutes and then flashes 3 diagnostic light
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?
Call back the people that installed it.
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Your work on the furnace may void the installers responsibility.
I would leave it alone and call the installer.
"Hey Lama, hey, how about a little something, you know, for the effort." And he says, "there won't be any money, but when you die, on your deathbed, you will receive total consciousness." So I got that goin' for me, which is nice. - Carl Spackler
what is the exhaust vent size? how many elbows? how many feet?
9ft with 5 elbows 2" pipe
Originally Posted by SuperTech2010
install manual says that this is acceptable, 20ft with 5 90's is what i am reading...is it lock out with 3 flashes? meaning open pressure switch during call for heat? it is working for a short time, so we are working until what happens? is this set up for 2stage auto, or 5min? i would look for somewhere water is pooling in the exhaust. did u pull the draft inducer off and check for small PVC shavings(i have found this a lot) getting into tubing. i am betting that there is no problems with the pressure switches, its doing this for a reason...
Originally Posted by sho1sho1
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