We have all been there. It is a hot summer day, and the air conditioner was working fine yesterday, but today it is not cooling properly. Or worse, it is not running at all. Before you call an HVAC repair contractor, you may be able to correct the problem yourself and perhaps save yourself some money. Here is a checklist of simple things to check before calling in an HVAC professional.
If the unit is not working at all:
- Make sure the power to the house and/or neighborhood is on.
- Check the thermostat and make sure the temperature setting has not been changed.
- Does the thermostat need new batteries?
- Check the outdoor condenser or the air handler/furnace. Make sure it is plugged in and check to be sure all power switches are in the on position. Double check the outlet—if it is a GFI, has the GFI been tripped?
- Check the air filters. They should be changed every three months. If they are old and dirty, the unit can be stressed and may malfunction and freeze up. Replace the filters and leave the system off for a few hours to allow it time to thaw. Then restart the system. If it is operating but not cooling, follow the guidelines below before calling for HVAC service.
- Check the circuit breaker to make sure it has not been tripped due to an overload on the system caused by simultaneously running other appliances on the same circuit. Turn off any other appliances and then reset the breaker. If it trips again, you may have a safety issue that needs to be checked by a qualified HVAC contractor.
If the unit is working but blowing warm air or not cooling well:
- Install fresh air filters.
- Turn the unit off and hose down your condenser. Hold the hose about four inches from the machine and use slow up and down strokes to clean off any debris. You should see brown dirty water coming out at the bottom of the machine. Let it dry for at least ten minutes before restarting the system.
- If the system is still not cooling, turn the unit off for an hour. Set the thermostat at the ambient temperature, and then lower it in increments of four degrees each hour. If that fails to return the house to a comfortable temperature, you need to call an HVAC contractor.
If the blower is on but the outside unit is not operating:
- This could be caused by a variety of issues indicating a need for replacement parts. You will need to call an HVAC contractor to inspect and service the unit.
Easy DIY way to determine if your system is operating efficiently:
- Make sure your air filters are clean. Acquire a refrigerator thermometer (available online or at a big box store). When the outside temperature reaches 80 degrees or higher, set your thermostat for about 70 degrees or a temperature significantly below room temperature. Let the unit run long enough to reach the set temperature. Place the refrigerator thermometer inside one of your air conditioner’s air ducts. After 10 minutes, note the temperature reading. Find your unit’s return air duct and use the thermometer to get the temperature inside there, as well. Subtract the first number from the second. If the difference is less than 14 degrees, your machine may be low on refrigerant and therefore running inefficiently. You should call a qualified repairman to inspect and service the unit as needed.
Easy DIY regular maintenance to help keep your system operating properly:
- Hose down your condenser and coils to keep it clear of debris.
- Change the air filters at least every three months. If you use the filters that are designed to clean the air of allergens and small particles, keep in mind that your unit will work harder because those filters are denser than the average filters.
- Check for water in the drain pan under the unit. If the pan has water in it, you should empty the pan, and you probably need to flush out the drain hose.
Your air conditioning system is likely the most expensive mechanical system in your house to install, maintain, and operate. As such, you are smart to have a service contract with a reputable HVAC contractor as a hassle-free way to keep up with regular maintenance. The contractor will check your HVAC system twice each year and perform routine service on it to keep it operating dependably, in the same way you have your car tuned up regularly. In between visits by your HVAC contractor, you should change the air filters and hose down the condenser before it becomes so covered with debris that its operating efficiency is compromised.
In summary, working with a good HVAC contractor to keep up with the routine maintenance on your air conditioning system will save you money in the long run. It may even prolong the life of the system!