System not functioning together

Central Florida. Home was built in 93, both the air handler and condenser were replaced in 2010-2011 before I bought the house. The thermostat may or may not be original...not sure but it is a pretty basic piece.

No issues until last light...which I am sure you get a lot here I do try to take care of my system by replacing the filter monthly and keeping the condensate line clear with bleach.

Last night I noticed it felt warm in the house. I keep thermostat set to 76 on auto. Thermostat said the system was on (has a green led) but the temp was 80. I noticed the condenser was on but the air handler was not. It was late and it has been cooling off lately so I shut the system off and turned on ceiling fans.

This morning I found the following:

1. I can turn the fan on manually at the thermostat and that will turn on the fan at the air handler as expected.

2. If I leave the system set to auto and turn the temp down to activate cooling, only the condenser outside turns on, the fan at the air handler does not. Also, sometimes this action of turning the temp down turns nothing on. Turning down then back up then down again typically works though and other times I have to turn everything off then back on again.

3. If I leave the system set to auto, turn the temp down and get the condenser to turn on I can then turn the fan on separately and everything works.

So, it seems everything only works together sometimes. Because of that, I can only think of there being an issue with the thermostat. As mentioned, it may be original. It has a small lcd display and is pretty basic and is something I have wanted to replace since we bought the house but I wanted a nicer wifi unit which is rather expensive. Maybe it is time to bite that bullet...

Could it just be the thermostat or could it be something else?

I would check the wire terminations / connections at the tstat , air handler & condenser .

At the furnace , check the voltage between the red & the common tstat wires at the furnace . Should be 24VAC or slightly higher .

With the tstat set to off , at the air handler , jumper red to green and yellow . Does the compressor & indoor and out door fans come on .

Report back .

God bless
Wyr

At the thermostat, I have the following:

connector label (wire color)

R (red)
G (green)
Y1 (yellow)
W2 (white)
W1 (red)
Y2 (none)
C (blue)

With the faceplate off, I measured the following voltages:

R-G 27.8 vac
R-Y1 28.2 vac
R-W2 28 vac
R-W1 28.2 vac
R-Y2 2 vac
R-C 28 vac

I pulled the cover off the interior air handler and there seem to be several different wire runs so I was not comfortable jumping anything there. At the thermostat, being that there are 2 red wires and the voltages are as above, I am not exactly comfortable jumping here either. Do the above numbers and colors/connections seem correct?

From my first post it had been working fine. I came home today and the system was off though the thermostat said it was on. I tried playing with the thermostat as I had done before but this time nothing would turn things on. After pulling the faceplate off a few times eventually everything turned on. I turned it off again and noticed a distinct and loud hissing sound come from the condenser only when it turns off. I did that a few times and it does the hissing every time it is turned off. I also noticed the metal line that runs into the condenser was frozen over. So, I may be dealing with a thermostat and possibly other things as indicated by the hiss and frozen line right?

Appears your transformer is outputting voltage OK .

If you feel comfortable . jumper R to G , indoor fan should come on , every time .

Jumper R to G & Y1 . Indoor fan and outside condenser should come on every time .

God bless
Wyr

WyrTwister said:

Appears your transformer is outputting voltage OK .

If you feel comfortable . jumper R to G , indoor fan should come on , every time .

Jumper R to G & Y1 . Indoor fan and outside condenser should come on every time .

God bless
Wyr

Click to expand...

Thanks, I did this last night. Fan and condenser turned on every time when connecting R to G and Y1.

Did you jumper it at the furnace or at the tstat ?

If at the tstat , then the tstat seems to have a problem .

If at the furnace , the tstat and / or tstat wiring may be the problem .

God bless
Wyr