Aux. heat light coming on with a/c on
It is about 85 degrees out and my a/c has been on as it has been all summer. I have been noticing that when the a/c shuts off because it's reached the temperature I've set it at the green auxiliary heat light on my thermostat (old school kind) comes on. Not only does it come on but it also flickers. But while the auxiliary heat light comes on the a/c is not running at the same time.
What could this possibly mean?
A/c seems fine otherwise. I just had the heat pump serviced for routine seasonal maintenance at the end of April.