Residential Plumbing & HVAC Experts

Troubleshooting Tips for a Malfunctioning Air Conditioner

With the summer heat around San Diego and San Marcos, a problem with your air conditioner can quickly leave you very uncomfortable. Knowing how to troubleshoot your A/C will help you get it running again or let you provide your technician with useful information about what might be wrong.

Free Up the Airflow

Poor airflow is a common cause of heating and cooling system malfunctions. It can impair the system’s performance and even shut down the system entirely. First, check your air filter and, if it’s covered in dust, put in a clean one. Next, clear out your air registers and vents. Remove the covers and vacuum out the insides of the ducts as far as you can reach. Wash the covers with mild detergent, then dry and replace them.

Finally, take a look at your outdoor condenser unit. If it’s plastered in grass clippings and leaves, shut down your system and use a stiff brush to clean the unit’s fins. Then remove the top and wash down the fins by directing a stream of water from a hose from the inside of the unit outward.

Inspect Your Components

If your condensate drain pump isn’t working, your air conditioner might shut itself off for safety reasons. Test your drain by pouring in a cup of water. If the pump doesn’t start up, either the float switch is stuck or the pump has failed. If you’re comfortable working with mechanical equipment, you might be able to open the pump and free the stuck float switch. Otherwise, contact an HVAC technician.

If your system runs, but can’t maintain an even, comfortable temperature, your thermostat could be the one to blame. Inside your thermostat is a small dial called the heat anticipator. If your A/C is cycling on and off too frequently, move the small arm on the dial one calibration mark toward the “longer” mark. If your system never produces the right temperature, move the arm away from the “longer” mark.

For more information on maintaining your air conditioner, check out Sherlock Heating and Air.