AC problem

General topics about all things heating, ventilation, air conditioning and refrigeration.

AC problem

Postby hitman1600 » Fri May 17, 2013 2:45 pm

My ac unit works fine downstairs but not upstairs. The fan doesn't even come on. When j turn the upstairs thermostat to cool the cool air indicator just blinks but nothing ever happens.I was thinking it may be a blown fuse in the upstairs unit since there's only one condenser and the downstairs side is operating correctly. Could you help? I've only been doing hvac for a few months and if I can avoid calling a tech out it would help. Its a Goodman cplj36-1b
hitman1600
New Contributor
 
Posts: 5
Joined: Fri May 17, 2013 2:41 pm

- AC problem

Postby Freon » Sat May 18, 2013 2:11 pm

You need to tell us more about your system. Do you have 2 air handlers, one downstairs and one upstairs. Does each air handler have an evaporator coil. Is each evaporator coil connected to its own condenser.

At the upstairs thermostat, set the FAN to ON, not AUTO. See if the blower works. If it doesn't, check the circuit breaker for the air handler. If the breakers are good, with the FAN set to ON, try and spin the blower squirrel cage and see if it will spin, even slowly. You may need to hold the blower compartment door switch closed so there's power to the blower motor.

If it spins slowly, then you need a new run capacitor, assuming an older, PSC motor.
Freon
Most Valued Contributor
 
Posts: 732
Joined: Sat Jun 18, 2011 11:26 am

- AC problem

Postby hitman1600 » Sat May 18, 2013 2:49 pm

I have only one condenser and one air handler. And yes there's an evaporator coil within the air handler. The thing is that the downstairs part of the ac comes on fine. But not upstairs. No fan no nothing. I've tried to put the fan on just on but still nothing. I know some systems have delays but I waited almost an hour once and nothing. From what a few people have told me it could either be a blown fuse or a bad fan motor. Nothing happens at all. No blower noise. No fan noise. Nothing. When I turn the thermostat to cool it says "cool on" while constantly blinking (Honeywell thermostat). Hope that is enough detail.
hitman1600
New Contributor
 
Posts: 5
Joined: Fri May 17, 2013 2:41 pm

- AC problem

Postby hitman1600 » Sun May 19, 2013 11:40 am

***UPDATE*** so I got a ladder and went up into the attic to the air handler.when I opened it up the blower was on and blowing air tto downstairs but not upstairs. One side of the evaporator coil was completely frozen so I turned the heat on to defrost quickly. To give a bit more detail there was a 2 zone control panel on the side of the air handler. When I followed the wires to the dampers I realized that the damper for upstairs had no power. The board indicated there was power but the board of the damper was nothing. The light was not on. Not red or green. Now I do know that there is a leak somewhere because the coil was frozen but does that damper not having power play a role as well? I'm going to call a service person out because I do not have the proper tools to fix it myself(r-22 scale low loss fittings nitrogen copper tubing) but I would like some insight for my own knowledge. Can somebody PLEASE give me some clarifications?????
hitman1600
New Contributor
 
Posts: 5
Joined: Fri May 17, 2013 2:41 pm

- AC problem

Postby Freon » Sun May 19, 2013 3:21 pm

Before you call anyone, see if you can get the damper door that is closed to stay open, even if you have to tie it open. The evaporator coil could easily freeze due to lack of adequate air flow thru the coil due to the closed damper door. You need to find out why there is no power to the damper. It could be a fuse, loose wire or something else. Trace the wires back from the board on the damper to the board on the air handler.
Freon
Most Valued Contributor
 
Posts: 732
Joined: Sat Jun 18, 2011 11:26 am

- AC problem

Postby hitman1600 » Sun May 19, 2013 3:35 pm

OK I'm about to go try it. But where would the fuse box be? I thought I would see it inside the air handler but i didn't.I also looked on the disconnects but it wasn't there as well.


***UPDATE***

so I'm up here now and found the fuse but the fuse is fine. One of my dampers seems to be operating fine but the other's indicator light is showing nothing. But on the control board its showing that it has power. Its a motorized damper I'm believing but how do I get the shutter inside to open up?
hitman1600
New Contributor
 
Posts: 5
Joined: Fri May 17, 2013 2:41 pm

- AC problem

Postby hitman1600 » Sun May 19, 2013 5:32 pm

***UPDATE -***
so I unscrewed the damper motor and boom! Found my problem. The damper motor was shot to hell. Excuse my french lol. So I tied the damper to one of my beams to leave it stuck open and I finally started to get air flow upstairs again. Now I just have to wait for my house to cool down. I'm going to still call my rental property to have someone come out to completely replace the damper. It won't cost me anything by going through them so to save me money its best to let them handle the rest. I'm satisfied with that. Especially seeing as I only have a year and 10 months of experience (epa certified though). My only question now though is it seems as if I'm not getting as much airflow as I used to before I had my problems. Its still WAY better than no airflow though. Could that possibly mean that my system is low on charge?
hitman1600
New Contributor
 
Posts: 5
Joined: Fri May 17, 2013 2:41 pm

- AC problem

Postby Freon » Mon May 20, 2013 1:18 pm

For the air flow, check all the filters and make sure all returns are are open. Also it is possible the evaporator coil is still partly frozen.
Freon
Most Valued Contributor
 
Posts: 732
Joined: Sat Jun 18, 2011 11:26 am


Return to HVAC General Forum

cron