The blower on a furnace is the part that actually pushes the heated air out into your home. Without the blower, the furnace can still heat the air, but the heated air will have nowhere to go. Problems with the blower can therefore greatly affect the efficiency of the furnace.
Here are three potential problems caused by a malfunctioning furnace blower – and how you and/or a furnace repair person can fix the problem.
Furnace Doesn't Produce Hot Air
The most obvious symptom of a blower issue is that the furnace stops putting out hot air. Check first that your thermostat is on the correct settings and that the thermostat isn't in need of new batteries. If the thermostat checks out, the problem is likely the blower.
If the furnace isn't blowing any hot air at all, the blower has either come completely disconnected or has failed. Those are both problems you want to leave in the competent hands of a HVAC repair person if you don't feel like you know about the furnace to fix it yourself. But you can get a sense of the problem by looking inside the furnace.
First, turn off all power to the unit. Remove the back to the furnace and locate the blower fan. Check to see if all of the fasteners seem secure. If the fasteners seem loose, tighten the fasteners according to the directions in your owner's manual if you feel comfortable performing such a fix. Replace the furnace cover, restore power, and try the furnace again.
If the furnace puts out hot air, you fixed the problem. Otherwise, call in some professional assistance, such as an employee at Comfort Heating & Air Conditioning, LLC.
Furnace Won't Shut Off
Does your furnace run even when the indoor temperature has met the setting on the thermostat? The blower fan might be running continuously whether you call for heat or not. This is likely due not to a problem with the blower itself but with the control panel that triggers the blower to run.
The control panel controls all of the mechanisms in the furnace so you don't want to mess with the panel unless you are extremely knowledgeable. Leave the control board fix to an HVAC technician if you aren't knowledgeable or you can risk completely frying your entire furnace.
Dry Air Issues
Another sign of blower issues is your home's whole-house humidifier ceasing to add enough moisture to the air. Most styles of humidifiers rely on blown furnace air to come through the humidifier where moisture is added via a soaked pad. The moistened air is then blown out into the house's ducts to mix with the normal furnace air.