It may be something simple. You may be able to solve the problem and save some money by checking a few things:

At the thermostat:

Is it on the correct mode for either heating or cooling?

Is it set to the temperature you want?

Is the display blank? Are there batteries in it?

Check the fan operation. On the thermostat, turn fan from “AUTO” to “ON”.

Do you hear it turn on?

Do you feel air movement?

If there is any strange noise, buzzing, or metal scraping noise, turn off and contact us.

At the circuit breaker box:

Is the circuit breaker for the furnace / air handler on?

At the outside unit:

If fan is working, then you may want to check outside unit.

Is this outdoor fan spinning?

Loud motor noise?

Small buzzing noise?

Is there any water by the unit? Is water coming from pvc drain from wall?

If the outside unit fan is spinning and not making an unusual sound, can you see any ice down below the fan on the coils?

If ice is seen anywhere, turn system off at thermostat (no heating and no cooing). At the thermostat, turn the fan to “ON”.

Let system run till all ice is gone and any water dripping has stopped.

Check air filter, replace if dirty.

Turn thermostat to “COOL” to check if it’s working.

Other possible issues:

Have a room that is either too hot or cold?

First try switching the the fan from “AUTO” to “ON” or “CIRCULATE”. Run the fan in this setting for a week or two to see if it helps moderate the area.

Mini split Heat pump systems are a possible option for rooms the are either too hot or too cold.