While there are a variety of furnace types—oil, gas, electric and dual-fuel—most heating systems operate in the same way using the same basic functions and mechanisms to deliver heat to your home. The blower motor in a heating, ventilation and cooling (HVAC) system is responsible for circulating the air throughout a building via ductwork. It forces air over the heat exchange (for heat) or the evaporator coil (for cooling), which moves through the ducts to reach various rooms to warm or cool them. If this motor malfunctions or breaks, the air won’t circulate, effectively hobbling the entire system. To keep a home or business comfortable in very hot or cold weather, the blower motor must be in good working order. (Some experts suggest that blower motors be inspected and oiled every year for this purpose.) If a blower motor breaks down, an HVAC professional can replace it for $400–$600, including parts and labor.
If a blower motor is a more expensive model, such as a newer variable-speed motor, replacement could cost up to $1,300. Variable-speed motors are less common, says Kevin Granados, owner of East Bay Heating and Air in Livermore, California, near San Francisco, but he recently gave a customer a quote of $940 to replace a variable-speed blower motor after the customer got a quote of $1,300 from a larger repair company. As a smaller company with less overhead, Granados says, his company’s rates for heating system installation and repairs are typically about 30 percent less than those of larger competitors in his area.
Standard blower motors operate at a single speed and cost around $450 to replace, including parts and labor. Variable-speed motors cost $600 and up to replace.
Components that can fail
Blower motors are made up of a motor, a blower wheel (also called a "squirrel cage") and the shell. The capacitor acts like a spark plug, creating the energy needed for the motor to engage. As a result, the capacitors undergo a lot of wear and tear, and it’s not uncommon for them to fail. Granados of East Bay Heating and Air charges $179 to replace a blower motor’s capacitor but says he’s seen other companies charge closer to $250. If a blade on the blower wheel gets bent or becomes loose, it could cause the unit to function noisily or improperly. Replacing a blade is not expensive, but most companies charge at least $80–$100 to have a service technician pay a visit.
Signs of a capacitor problem
As noted, a malfunctioning capacitor can cause problems with the blower motor and is less expensive to fix than replacing an entire motor. Most systems have two capacitors: the start capacitor, which provides the energy boost needed to start the motor, and the run capacitor, which regulates the flow of electricity to the motor. Here are some indicators of a malfunctioning start or run capacitor:
Blower motor won’t turn on or functions intermittently
Furnace brand should not drastically affect the cost to replace a blower motor because many furnace makes and models—including Carrier and Trane—use the same internal components. The only manufacturer that uses its own branded internal parts is Lennox, which is one reason Granados of East Bay Heating and Air doesn’t recommend Lennox systems to customers who are putting in a new furnace.