Usually this is low refrigerant charge causing the evaporator temperature to go below freezing resulting in an impenetrable mass of ice building up on the evaporator coils. The blower would then be under high back pressure. There may be a safety system that shuts off the blower motor if the back pressure is too high.
Why AC blower stops working after a while?
The AC’s contactor switch, located inside your compressor unit, sends voltage to the condenser unit and fan so they will run. These switches can go bad over time, causing your fan to stop working properly.
Why does my blower motor keep turning off?
Closed or Blocked Air Supply Vents.
If your furnace keeps shutting off, check your air vents to see if any of them are closed or blocked in any way. You should keep all your vents open, even in the rooms you don’t use. If your heat exchanger doesn’t get enough air, it can’t transfer enough heat.
What can cause a blower motor to fail?
The main causes of failure are loss of lubricant, a failed run capacitor, a failed bearing in a belt drive, a little water dripping into the windings or a voltage problem. So technicians should carefully check to find the cause of a failure before changing the motor.
What would cause a furnace blower not to kick on?
If you see or hear the fan turn on, your blower motor is not the culprit. If the fan does not start, you have a wiring issue (circuit breaker trips) or motor problem (circuit breaker does not trip). While your thermostat may be at fault, only an HVAC technician can diagnose and remedy the issue correctly.
How do you reset an AC blower motor?
Locate the reset button on the furnace and press it to reset the furnace. It is usually located inside the blower compartment on the side of the blower motor. Be cautious as the housing may be hot. If the button is popped up, press it down.
How do I reset my blower motor?
How to Find and Reset your Furnace Motor Blower
- Step 1: Turn off the power to the furnace. …
- Step 2: Remove the blower compartment cover. …
- Step 3: Make sure the blower is completely cooled off. …
- Step 4: Locate the reset button. …
- Step 5: Press the button in (assuming that this is your issue and that the button has popped).
Why does my blower motor keep turning on and off?
So if your furnace blower is turning on and off when the furnace isn’t in a heat cycle, it usually means the fan limit switch is defective. Unless you’re familiar with the components of your fan limit switch and how it works, we suggest letting a professional repair or replace the switch.
Why does my furnace turn off after a few minutes?
Dirty or faulty flame sensor
If your furnace turns off after a few minutes, there is a good chance it is caused by a faulty or dirty flame sensor. This vital component is designed to keep an eye on the gas burner. When it cannot sense that burner, the furnace runs then shuts off and starts again.
How long should blower run after furnace shuts off?
Typically, because the oil or gas burner is NOT running (because the thermostat is not calling for heat), the blower fan should not run more than a minute or two before stopping.
How do you know if your HVAC blower motor is bad?
Signs of an Overheating Blower Motor
- A “hot” or burning smell from vents in the home. This symptom is often coupled with the furnace shutting off completely. …
- Loud humming and other unusual noises. We have many homeowners call us mentioning humming and other odd sounds. …
- Furnace cycles off and refuses to restart.
How do I know if my HVAC blower motor is bad?
How To Check your Furnace Blower Motor (7 Steps)
- Step 1: Turn off all power to the furnace. …
- Step 2: Remove the Furnace Access Panels. …
- Step 3: Use your voltage tester to ensure no electricity is flowing through the furnace. …
- Step 4: Feel the area near the blower motor to determine if it’s hot.
