The red light is showing on but not real bright. The air conditioning seems to be running fine, and seems to be cooling. Do I need a new thermostat controller unit? I already flick the outside switch to the main box off for a short time, and then turn it back on.

Is this a new unit or are you new to this home? Try raising the stat to something high like 80 degrees, tel us if the cooling stops.

Is this a new unit or are you new to this home? Try raising the stat to something high like 80 degrees, tel us if the cooling stops.
This is an older house, and the thermostat unit is probably 13 to 15 years or older. I did what you told me to do. I raised the temperature to 85 degrees, and it still heats & cools like nothing is wrong. The red light went off & the green aux light came on. I turn it off the heat, and then set the temperature to 74 degrees, but the green light that is normally on was showing the green. It went all the way down to 74 degrees, and kick off normally. I even tried to flick the switch to emergency mode, and the red light was very bright then.

http://www.patriot-supply.com/files/icmsc2200_ag.pdf


There are three LED indicators located on the front of the thermostat. They are designed to inform you of
the following:
AUX (GREEN): This turns on when the auxiliary (back-up) heating is in operation. This is the second (noneconomy)
stage of heat. It turns on 2 degrees below first stage and is not adjustable.
CHECK (RED): When this turns on, a malfunction has occurred somewhere in the heat pump system.
Please contact a qualified service technician as soon as possible to check your system.
EMER (RED): This light turns on whenever the emergency heat is manually selected (system switch is in
the EMER position). While in the emergency heat mode, the heat pump compressor is off,
and the emergency heat (same as the auxiliary heat) maintains the setpoint temperature.

Is it very cold where you are? Sometimes your heat pump is working harder than normal, or has kicked in a backup or auxilliary/supplemental system to keep up with the temperature load. Make and model of your heat pump and you can verify this condition, before you assume it's a malfunction.

http://www.patriot-supply.com/files/icmsc2200_ag.pdf


There are three LED indicators located on the front of the thermostat. They are designed to inform you of
the following:
AUX (GREEN): This turns on when the auxiliary (back-up) heating is in operation. This is the second (noneconomy)
stage of heat. It turns on 2 degrees below first stage and is not adjustable.
CHECK (RED): When this turns on, a malfunction has occurred somewhere in the heat pump system.
Please contact a qualified service technician as soon as possible to check your system.
EMER (RED): This light turns on whenever the emergency heat is manually selected (system switch is in
the EMER position). While in the emergency heat mode, the heat pump compressor is off,
and the emergency heat (same as the auxiliary heat) maintains the setpoint temperature.

This article may help you shed some light on a heat pump problem. Make and model would be helpful.

Heat Pump Troubleshooting & Repair | HomeTips (http://www.hometips.com/repair-fix/heat-pump.html)

Post number 1 says he is cooling so it can't be cold where he is located. He is certainly not near Chicago, we will see -12 tonight.

Yes I edited after I reread his post. Cold in Texas too!!!!!!

Post number 1 says he is cooling so it can't be cold where he is located. He is certainly not near Chicago, we will see -12 tonight.

I'm located in Saint Petersburg, Florida running approximately from 50 to 75 in last couple of weeks