Heat Pump Help

sammydog01 thought this was worth mentioning said
3

It was 8 degrees below the cold setting in my house this morning and the heat pump was still blowing cold air.

I turned the temp setting up- blowing cold air.

Set the thermostat to off- still blowing cold air.

Set the thermostat to heat and set it to 90- still blowing cold air.

Turned off the breakers- no cold air. Turned them back on, cold air on all settings including off.

Is it worth driving to Home Depot an buying a new thermostat or is it time to call in a professional? Thermostats are pretty easy to install, right?