A Few Things To Check On Your Furnace When The A/C Isn't Working

Most central air conditioning systems use the blower fan on your furnace to get the cool air throughout your house. If you notice that the A/C unit is running, but there is no cold air coming out of the vents, there are a few things to look on your furnace before calling the HVAC technician.

The Furnace is Turned On

One of the first things to check is that the furnace is turned on. The problem could be at the circuit breaker, or the unit itself could be switched off.. Sometimes, it will look as if the breaker is fine, but it is not. Flip the breaker to the "off" position and then back to the "on" position. The next step is to go to the furnace and check the "on/off" switch. This is generally located beside the unit and looks like a normal light switch. In most cases, "on" is the "up" position. If the unit is off, turn it back on. 

Blower Safety Switch

If you have made sure that the system is turned on, and it is still not running, the problem could be the blower safety switch. Your furnace has a small door on the side of it that is called the blower door. Inside this door is a button similar to the light button in a refrigerator. If the blower door is not seated properly, the button will not be pushed.  If the button is not pushed, the blower motor will not work on the furnace. It is also possible that this button will keep the a/c motor from running. With the system turned on, push on the button to see if the motors start working again. If the motors do not come on now, close the door and check all the filters. 


You may have already checked and cleaned or replaced the filters in the return air vents in the house. However, there may also be a small filter on the side of your furnace that needs to be cleaned. Go to the furnace and look for some type of grill. Open the grill and you should see a filter inside. This is the piece that needs to be cleaned or replaced. If it is dirty and clogged, the furnace cannot get any air.

There may be a switch that will turn off the system when there is no airflow. Before putting in the clean filter, look for a small reset button just inside where it sits. This will turn the system back on when the filter is put in place.

Do not just assume that because your house is not cooling properly the problem is with the air conditioning unit. Checking to make sure that everything is working properly with the furnace may save you from needing hvac repair. If checking the power, safety switch, and filters does not get the system running, it is time to call the technician. A company like HomeSmart Xcel Energy can provide you with more information about troubleshooting your air conditioner.