Heating & Cooling Troubleshooting

Get basic answers to common operating questions to keep your air Conditioning & heating system running at peak performance.

Keep your system up and running with these convenient tips that address common operational issues. If these simple steps do not solve your problem, please call T H K Heating & Air Conditioning (310) 977-9454.

Air Conditioning Troubleshooting Guide

Is your thermostat set in the "cool" position (or "warm" for winter heat pump operation)?
If so, is your outdoor air Conditioning or heat pump unit running?
Did the circuit breakers in the circuit breaker box (or electrical panel) trip to the "OFF" position?
Is the outdoor "disconnect switch" on your outdoor unit in the "ON" position? (The disconnect switch is usually a small metal grey box mounted on a wall near the outdoor unit.)
Is the blower motor in your furnace or air handler running when your thermostat is activated? (Make sure the furnace switch is in the "ON" position.)
Have you changed your filter? (A blocked filter can cause your unit to shut down due to lack of proper airflow.)
Are the air registers (supply or return ducts) plugged?

Gas Furnace Troubleshooting Guide

Is your thermostat set in the "heat" position?
Is the temperature setting on the thermostat set higher than the thermostat's indoor temperature?
Is the power turned on for your furnace? (At the thermostat, turn the fan to "ON." The fan should run when power is being supplied to furnace.)
Did the circuit breakers in the circuit breaker box (or electrical panel) trip to the "OFF" position? (Check the SSU light switch on the gray box located at the furnace to make sure it is in the "ON" position.)
Have you changed your filter? (A blocked filter can cause your unit to shut down due to lack of proper airflow.)
Are the air registers (supply or return ducts) plugged?