Anyone know about thermostats?

Coldest night of the year and our heat isn't heating. It's 11 degrees F outside. Our thermostat is always set on 72-74 depending ( I have hot flashes/cold chills often).

All last night our thermostat was set on 74 and its only 65 in here. We are freezing. The vents are blowing out lukewarm/almost cool air. It also reads AUX heat.

Any help or ideas on why its so cold in here? The system is brand new (just installed late summer) , so there shouldn't be anything wrong with it.

Um.
When ours did that, it was because the compressor in the furnace needed replacing.

Quoting Saffy Sly:" Um. When ours did that, it was because the compressor in the furnace needed replacing. "

I keep reading AUX is a normal thing for certain temperatures, its like backup heat when the normal heat can't get warm enough to keep up. But it looks like if that was the case it'd at least still blow out warm air. Ugh. Always something for us. Guess I'll have to call the landlord.

Do you have a fan switch. It should be set to auto (the fan) if its set to on then it will blow out cold air

When ours did that the other day the pilot light was out on the water heater. I had no idea those were connected in my townhouse but apparently they are lol.