View Full Version : Fan comes on, so does heat, but no A/C
JEStor
May 13, 2010, 05:48 PM
My AC just died the other day while I was at work, came home and it was ungodly hot. Normally keep it at about 72 all the time. The heat works fine and the fan comes on if I set it to "ON" and it comes on if set to AUTO and to COOL, but no AC. The outside unit doesn't come on and neither does the upstairs unit. Pulled open the vent and it has a large drip pan underneath which was rather full, also had a AQUAGUARD sensor in the pan. I was hoping that was the problem but I drained the pan and still no AC, I even unwired and bypassed the sensor but no love.
The unit is a Goodman ARUF36421BA. I know electronics and wiring but I'm no HVAC guy.
My question is should that catch pan even be filling? It should be draining out a drain pipe yes? Is there another internal sensor saying maybe the drain pipe is clogged or something?
I have no idea and if I don't fix it myself ill have to wait till the landlord can get a HVAC guy out here and I'm in san antonio and its almost 90 degrees in my house, I don't want to wait :(
Thx in advance for any help you can give me.
JEStor
May 13, 2010, 05:49 PM
Also its rather new, the house is only 3 or 4 yrs old.
T-Top
May 13, 2010, 06:34 PM
Not uncommon for a second drain switch to be installed in the drain line. If you do have one you will see two wires leaving the air handler going to it.
JEStor
May 13, 2010, 06:56 PM
I read the install manual that was inside the closet (it was vague, made for someone who already knows what's going on), but I'm still not 100% sure what I'm looking for as far as the drain goes, there is a PVC that is running down into the floor and its insulated and has a catch elbow in it about a foot down, there is also a 1" copper tube and about a 1/2'' copper tube. The PVC is the drain right? I will look for the other drain switch, but I don't remember seeing one though.
JEStor
May 13, 2010, 07:02 PM
Also the PVC has a T split at the top before drops down into the floor. One coming from the handler, one going into the floor and one going straight up with a piece of PVC that wasn't glued in. So if its clogged or something can I just pour draino or bleach or something down there to clean it out?
T-Top
May 13, 2010, 07:11 PM
The pvc is your drains, copper refrigerant lines. If the problem is from a drain line switch it would be located at the evaporator coil.
JEStor
May 13, 2010, 07:46 PM
Is there a way I could recognize the sensor wires and I could just bypass them the way I did the aquaguard one? I just want to make sure that this is what's causing the problem and that the AC still actually works, if I know it works then I can cool down the house for now and have some time to get the problem fully rectified.
hvac1000
May 14, 2010, 07:00 AM
Also the PVC has a T split at the top before drops down into the floor. One coming from the handler, one going into the floor and one going straight up with a piece of PVC that wasnt glued in. So if its clogged or somthing can I just pour draino or bleach or somthing down there to clean it out?
NO NO NO to the Draino idea!! Usually compressed air or other pressure is used to blow the clog clear. Bleach is also a bad idea unless you really know what you are doing. Bleach works on mold removal but it must be mixed down to no more than a 10% solution for safety since it is possible the blower might pick up the fumes and make a problem within the dwelling.
JEStor
May 14, 2010, 01:47 PM
I figured that might cause issues. I have an air compressor so I might give that a try. I looked for another drain swich but I couldn't find anything. If another switch was hooked up, any idea what I would be looking for in the wiring harness? When it was installed all the wiring from the thermostat and the outside unit was just twist capped and left hanging in the closet so its all pretty easy to check it all out.
hvac1000
May 14, 2010, 02:20 PM
I figured that might cause issues. I have an air compressor so I might give that a try. I looked for another drain swich but I couldnt find anything. If another switch was hooked up, any idea what i would be looking for in the wiring harness? When it was installed all the wiring from the thermostat and the outside unit was just twist capped and left hanging in the closet so its all pretty easy to check it all out.
Usually the drain overflow safety switch is wired somewhere into the low voltage control wiring. It is wired in such a way as to break the connection of the 24 volt control circuit so the outside unit will not run. As far as physical location the drain pan itself or the PVC pipe could contain the switch.
JEStor
May 14, 2010, 03:20 PM
So is this the most likely cause of my problem since its just the AC that doesn't work?
JEStor
May 14, 2010, 03:31 PM
So is this the most likely cause of my problem since its just the AC that doesnt work?
I am referring to a 2nd sensor.
JEStor
May 15, 2010, 03:16 PM
I poured some water down the drain and it filled up and took forever to drain out. There is also nasty crap all in the pipe, but I can't find another sensor anywhere, looks like I might just have to get an HVAC guy out here :(
JEStor
May 15, 2010, 03:29 PM
Is using a pipe snake OK on these things?