Unusual and Loud Sounds
A failing blower motor may emit unusual sounds. This may sound like screeching or squealing if it has bad bearings. You may hear a rattle or a banging sound if something inside the motor has broken or come loose.
A Failed Motor
An HVAC blower motor will occasionally fail due to age, wearing out, or not being cleaned regularly. Symptoms may include strange noises, burning smells, or just plain refusing to turn on. If this happens and the motor is no longer operable, a new blower motor may be needed.
If the motor is making rattling, clanking, or banging sounds, it may be because of a loose or broken part inside the system. Loud banging sounds are especially worrisome. They're usually a sign that something within the system is damaged or disconnected, potentially indicating the need to replace the blower motor.
Blower motors are designed to last just as long as your furnace itself, anywhere from 10 to 20 years. Just as with any HVAC system, the better maintained and serviced your equipment is by experienced HVAC technicians the longer it will last and the fewer repairs you'll face.
A blower door test is highly valuable because it will identify where your home's air is escaping from. Once you know the location of air leaks, you can fix the problem and save money in all that wasted energy. The average cost for a blower door test is around $325, though it may range between $200 and $450.
Blower Motor Resistor Test
Typically, if the fan will work on some speeds but not on others, the resistor is suspect. Okay, let's say there's no melting going on, but your fan doesn't work on all speeds. Typically, if the fan will work on some speeds but not on others, the resistor is suspect.
It typically takes one to four hours for the technician to replace the AC fan motor. Normally, good technicians will check for other issues during this replacement. If more problems are found, they will be repaired as well.
Replacing the blower motor is likely the best decision if your furnace is under warranty or relatively new. It might be better to replace the furnace if it's old or has a lot of issues that require frequent repairs. On average, a new blower motor costs $300 to $900.
If your blower motor is not functioning properly, it can't circulate air through your AC system, causing the evaporator coil to become too cold and eventually freeze up.
On some platforms, a faulty blower motor relay will cause the blower not to work at all, which means there will be no airflow from the A/C. On others, the blower won't work on “high blow” but all the other speeds will work. The blower motor relay fails because it regularly deals with high current loads.
This fan is powered by a motor, and like most HVAC components, that motor sometimes fails. The older your furnace is, the more likely this is to happen. Luckily, residential HVAC contractors can usually replace or repair broken blower motors.
The cost of an HVAC trip charge can vary significantly depending on your location, the HVAC company, and the time of day. On average, it can range from $50 to $150 or more.
The blower door test itself can run for about a half an hour. You may want to walk around your home with your energy advisor as the test is running! It's a great way to physically feel the movement in the air and pinpoint exactly where the leakage is coming from.
Typically, the lifespan of furnace blower motors spans from a minimum of 10 years up to about 20 years, with most enduring an average period between 15 and 20 years.
Since the module regulates the entire AC system, inconsistent cooling, out-of-date software, and uneven air distribution are typical signs of a broken AC control module.
One of the most frequent causes of a malfunctioning blower motor is electrical issues. These can include blown fuses, tripped circuit breakers, or faulty wiring. Check your home's electrical panel for any tripped breakers or blown fuses and reset or replace them as needed.
Some of the reasons a blower motor might fail are overheating, and excessive moisture. When dust, dirt, and debris build up, it can cause the windings and bearings to burn up more quickly.