Outside AC unit will run once then won't again unless reset and wait?
#1
05-26-16, 09:31 PM
Join Date: May 2016
Location: USA
Posts: 20
Upvotes: 0
Received 0 Upvotes
on
0 Posts
Outside AC unit will run once then won't again unless reset and wait?
Hello everybody. Great to be here. 
Thanks for sharing great info!
-I have an amana hi efficiency 12 outside AC unit.
-Problem is the outside unit will run fine ONCE then will not start again when called upon until I flip breakers off and wait ~1hr. (reset)
-The inside fan/blower works fine and keeps running but will not turn outside unit on after the first run cycle.
-I have changed the contactor and cleaned coils. I have cleaned out drain hose (was not dirty). Still the same issue.
-Also checked the copper pipe going to unit and it is cool
-I look at the control board after this happens and LED blinks once telling me lockout.
-The fan on outside unit does sound a little rough but nothing major. (to me)
Any help folks is greatly appreciated. Love being a DIYer but this one has got me stumped! THANKS!!!
Thanks for sharing great info!-I have an amana hi efficiency 12 outside AC unit.
-Problem is the outside unit will run fine ONCE then will not start again when called upon until I flip breakers off and wait ~1hr. (reset)
-The inside fan/blower works fine and keeps running but will not turn outside unit on after the first run cycle.
-I have changed the contactor and cleaned coils. I have cleaned out drain hose (was not dirty). Still the same issue.
-Also checked the copper pipe going to unit and it is cool
-I look at the control board after this happens and LED blinks once telling me lockout.
-The fan on outside unit does sound a little rough but nothing major. (to me)
Any help folks is greatly appreciated. Love being a DIYer but this one has got me stumped! THANKS!!!
#2
05-27-16, 05:58 AM
Member
If you have a voltmeter/multimeter, check the control signal voltage where it comes into the outside unit from the house. The control signal is nominally 24VAC and should be present when the thermostat is calling for cooling. The control signal voltage normally is carried from the house to the outside unit via a small conductor cable (usually 2 wires). It attches to the wiring inside the outside unit using wire nuts. With the thermostat calling for cooling, check to see if you have ~24VAC across the two control signal wires coming from the house (not to be confused with the main 240VAC power coming into the outside unit). Do this when the unit isn't working (the 24VAC should be present when it is working). If there is no 24VAC present, the problem is likely inside at the furnace/air handler end (since it's intermittent, I'm assuming you don't have a broken wire going from the house to the outside unit).
#3
05-27-16, 09:19 AM
Join Date: May 2016
Location: USA
Posts: 20
Upvotes: 0
Received 0 Upvotes
on
0 Posts
Thanks for the info. Just to be clear check for 24vac at the wire nut when it is working/running?
#5
05-27-16, 09:37 AM
Group Moderator
Welcome to the forums.
What board blinks once...... inside the furnace ?
If the condensor has a control board in it..... we're going to need the model number for the condensor.
-I look at the control board after this happens and LED blinks once telling me lockout.
If the condensor has a control board in it..... we're going to need the model number for the condensor.
#6
05-27-16, 11:41 AM
Join Date: May 2016
Location: USA
Posts: 20
Upvotes: 0
Received 0 Upvotes
on
0 Posts
#7
05-27-16, 12:05 PM
Join Date: May 2016
Location: USA
Posts: 20
Upvotes: 0
Received 0 Upvotes
on
0 Posts
Ok, I tested for voltage at the wires coming from the house into AC unit with the AC not running. I am getting nothing on the volt meter. So I assume that means the furnace board is in lockout and not sending any power? If correct, what does this mean?
#8
05-27-16, 01:41 PM
Member
You are correct, the problem is not with the outside unit, but somewhere in the furnace/air handler. You will have to research what the one blink LED (lockout) means. It may be a problem with the furnace control board. If you have the manual on the furnace, it may help you understand what the "lockout" mode means. Normally, lockout occurs when a sensor indicates a malfunction a set number of times, and usually occurs in heating mode, not cooling mode. If you post the make & model number of your furnace, we may be able to help you further.
#9
05-28-16, 01:00 PM
Join Date: May 2016
Location: USA
Posts: 20
Upvotes: 0
Received 0 Upvotes
on
0 Posts
Ok,
Furnace model- Amana air command 80sse
Control Board- White Rogers 50A50-298
Now, you saying that got me thinking. I replaced my thermostat in fall of last year and now thinking about it never checked to see if cooling worked. Could this be leading from the thermostat not being wired correctly? I can post pics of how thermostat and inside furnace are wired.
Thanks for all the help!
Furnace model- Amana air command 80sse
Control Board- White Rogers 50A50-298
Now, you saying that got me thinking. I replaced my thermostat in fall of last year and now thinking about it never checked to see if cooling worked. Could this be leading from the thermostat not being wired correctly? I can post pics of how thermostat and inside furnace are wired.
Thanks for all the help!
#10
05-28-16, 03:10 PM
Member
In reading the service manual, it appears that a single flash of the control board LED (what I understand you're seeing) indicates that the burner didn't fire up properly. This indicates that the furnace thinks that it's in heating mode, which does indicate a likely thermostat wiring issue. Check to make sure that the R, G, Y, and W wires are connected to the proper terminals. You should see terminals with the same letters on the furnace control board. Make a note of which wire color is connected to each labeled terminal. At the thermostat, make sure that the same colored wires are connected to the corresponding labeled terminal. In other words, you want to connect R to R, G to G, Y to Y, and W to W. Ideally, the wire colors would be Red, Green, Yellow, and White. However, depending upon the wire used (between the thermostat and furnace), the colors could be very different.
#11
05-28-16, 03:24 PM
Group Moderator
Most definitely a stat/wiring problem.
Yes.... the board is in lockout but the A/C would still work. The board may keep the blower from operating properly but the condensor would still operate.
Yes.... the board is in lockout but the A/C would still work. The board may keep the blower from operating properly but the condensor would still operate.
#12
05-29-16, 11:39 AM
Join Date: May 2016
Location: USA
Posts: 20
Upvotes: 0
Received 0 Upvotes
on
0 Posts
Here is how the thermostat is wired. There are two extra wires (red and white) that are wired to the control panel but do not hookup to the thermostat. Is this the correct wiring?
[IMG]
[/IMG]
[IMG]
[/IMG]
[IMG]
[/IMG][IMG]
[/IMG]
#13
05-29-16, 11:58 AM
Member
From your pictures, it appears that the thermostat is wired correctly. The extra white wire is Common (chassis ground), while the extra red wire is 24VAC. They are probably coming from the 24VAC transformer. The W (white) wire is the one that controls the burner. Try temporarily disconnecting the white wire from the W terminal on the furnace and see if the problem continues.
#14
05-30-16, 04:50 AM
Member
Join Date: May 2006
Location: US
Posts: 726
Upvotes: 0
Received 0 Upvotes
on
0 Posts
#15
05-30-16, 07:44 AM
Group Moderator
There isn't any indication of a float in the wiring pictures.
It just occurred to me why the condensor only runs one time and trips the breaker. In the picture the condensor is connected to constant 24vac. When the inside blower shuts off the compressor goes into high pressure overload. It probably cycles a few times on overload and then trips the breaker. Pretty hard on the compressor. You should have heard it cycling.
The 24vac from the transformer is not connected at the thermostat connections..... it's connected at the 12 pin plug.
That two wire cable is from the outside condensor. White on C is correct. The red is connected to R but it is supposed to be on the Y terminal with that black wire.
It just occurred to me why the condensor only runs one time and trips the breaker. In the picture the condensor is connected to constant 24vac. When the inside blower shuts off the compressor goes into high pressure overload. It probably cycles a few times on overload and then trips the breaker. Pretty hard on the compressor. You should have heard it cycling.
The 24vac from the transformer is not connected at the thermostat connections..... it's connected at the 12 pin plug.
That two wire cable is from the outside condensor. White on C is correct. The red is connected to R but it is supposed to be on the Y terminal with that black wire.
#16
05-30-16, 10:01 AM
Member
Pete, good catch. You're right, the "extra" white & red are the control signal cable running to the outside unit. That likely explains why the system is behaving like it is.
#17
05-30-16, 12:36 PM
Join Date: May 2016
Location: USA
Posts: 20
Upvotes: 0
Received 0 Upvotes
on
0 Posts
Ok guys, with the white wire NOT attached to W and the Red 24VAC wire attached to Y we have been running normal for a few cycles now! Should I try reattaching the White wire to W or wait until I need heat to do so. I have not had a problem with heating. I really appreciate the help you guys! You guys rock!
Should I try reattaching the White wire to W or wait until I need heat to do so. I have not had a problem with heating. I really appreciate the help you guys! You guys rock!
#18
05-30-16, 01:30 PM
Member
Pete found the problem. You can hook the white wire back to the W terminal and it should continue to work correctly. Leave the red wire connected to the Y terminal on the air handler terminal block.
#19
07-13-16, 08:26 PM
Join Date: May 2016
Location: USA
Posts: 20
Upvotes: 0
Received 0 Upvotes
on
0 Posts
Hello again guys! Hate to bump this thread again... So after arriving home from a 4 day vacation I come to find that the outside AC unit is not coming on again. Unit had been working fine after the previous wiring issue. Thermostat calls for cool/clicks blower comes on and runs runs runs. No cool air/temp change. I am not hearing any sound coming from the outside unit. No hum/buzz nothing!
-Have checked breaker.
-Replaced contactor and fuses.
-Replaced filter.
-Cleaned coils.
Still no change. No sound at all coming from outside unit.
Any ideas? Thanks so much for all the previous and hopefully future help!
-Have checked breaker.
-Replaced contactor and fuses.
-Replaced filter.
-Cleaned coils.
Still no change. No sound at all coming from outside unit.
Any ideas? Thanks so much for all the previous and hopefully future help!
