7 Facts on HVAC Blower Motor: What, Size, Type, Replacement

Cold patches develop because single-speed motors only operate when the thermostat instructs them to. Let us talk of the HVAC blower motor size, type, and replacement alternatives.

HVAC blower motors that only operate at one speed produce air. Blower motors with variable speeds can change their speed to blast air at various speeds. An operator’s home’s HVAC system still depends on a blower motor that is operating properly.

A blower motor cannot emit any type of air with input. The won’t either be air flow from the heat and cooling system ports as a result. In this article, we will go into more detail on a lot of subjects, including what an HVAC blower motor is, how it acts, where it is located, how big it is.

What is HVAC blower motor?

The blower motor resister is used to supply power to the blower motor. Let’s go over the definition of an HVAC blower motor.

The HVAC blower motor is about what moves conditioned air from the furnace, HVAC unit, or air conditioning system into the dwelling through into the heating and cooling system. The blower motor propels heated or cooled air through the ductwork and out of outlets scattered around the dwelling.

If the HVAC system’s blower motor failures and the valves are left without ventilation.

HVAC blower motor working

The temperature in the house is kept by thermostats in collaboration with the heating and cooling systems. Let us observe the HVAC blower motor in action.

The blower motor alerts the heater to work when the temperature decreases far below thermostat set. The operator’s home’s furnace emits hot or cold air, which is then routed seen between house’s various rooms. The blower starts up at this stage.

640px HVAC Pipes 1
Image – Heating, ventilation, and air conditioning (HVAC) pipes by Aidan ( CC-BY-2.0 )from Wikimedia Commons

The blower motor then moves the warm or cool air made by furnace around the house so that the temperature is held at the set preset by the thermostat. Huge amounts of air can be pushed even with a small blower motor.

HVAC blower motor location

When in use, single-speed motors run at their maximum energy efficiency and at one speed. Let us look at where the blower motor is located in the HVAC system.

Regarding furnaces, the blower motor is situated adjacent to the air filter in the base of the appliance. The blower motor for the majority of HVAC units and air conditioners is positioned in the air handler.

It is indeed feasible that some utilities, typically the furnace and air conditioning system, might use a blower motor in the air handler.

HVAC blower motor size

Blower motors come in two basic assortments: single-speed motors; variable-speed motors. Let us judging by the size of the, single – speed HVAC blower motor.

Frame sizeDiameter (mm)Typical torque range for stepper (Nm)Typical torque range for stepper (RPM)
NEMA 8200.01 – 0.040 – 1000
NEMA 11280.06 – 0.120 – 1000
NEMA 14350.05 – 0.50 – 1000
NEMA 16390.1 – 0.250 – 1000
NEMA 17430.2 – 10 – 1000
NEMA 23570.5 – 30 – 1000
NEMA 24601.2 – 4.60 – 1000
NEMA 34863 – 120 – 1000
NEMA 4210212 – 200 – 1000
Different types of HVAC blower meter, their features,and respective cost

The most typical application of a blower motor is in forced air HVAC systems. Automobiles also have blower motors, which are a component of the system in charge of distributing heated air across the automobile when the heating system is turned on.

HVAC fan blower motor

The blower motor is one of the furnace’s most labor-intensive components. Let us check out the blower motor for the HVAC fans.

A fan blower motor is a part of a Heating, ventilation, and air conditioning system that circulates the exhaust air into the owner’s home’s rooms after it leaves the system. Simply pull the blower motor from the HVAC system and scan the monitor for the resistance reading to inspect the blower motor.

If the measurement is O.L. or nothingness, the device needs to be changed because there is a voltage drop.

When does HVAC blower motor starts then stops?

Until the heating cycle is finished, the HVAC blower motor should be continuously running. Let us examine the blower motor for the HVAC to see when it starts and stops.

  • When the heat exchanger of the HVAC system experiences an extremely low temperature, the blower motor starts and stops.
  • When the HVAC blower motor starts and stops; the heat exchanger in the HVAC system is exposed to temperatures that are too high.
  • The blower motor in the HVAC starts, then stops an excessively large furnace for the house.
  • HVAC blower motor duct design is inadequate.

The furnace blower fan should start on 1.5 to 3 minutes after the thermostat signals a need for heat and should go off several minutes after the heating cycle is complete under typical circumstances.

HVAC blower motor replacement

The blower motor’s single speed operates at maximum efficiency. Let us examine the replacement of the HVAC blower motor as a symptom.

  • Mysterious noises
  • Continuing to increase energy prices
  • Security issues
  • There must be ongoing maintenance on the blower motor
  • Approximately to ten years old

Mysterious noises

Whenever customers hear strange noises, the HVAC unit system needs to be reviewed if the operator can distinguish between normal and unsettling noises the HVAC unit makes as it operates. It can be a sign that it needs to be changed.

Continuing to increase energy prices

If the operator does nothing despite rising electricity costs, the HVAC unit is not using energy efficiently. If the operator’s heating system is working harder to provide the same amount of warmth and cooling, a HVAC unit replacement can help to lower those energy costs.

Security issues

If the HVAC unit has a carbon monoxide leak, the owner and their family could be at serious loom for health problems. A blower motor ought to be fitted in the place of the heating unit if it leaks.

Ongoing maintenance on the blower motor

Occasional maintenance is required for the HVAC unit blower motor due to typical ageing wear and tear. However, if the operator fixes the blower motor correctly, the HVAC unit can proceed quickly.

Approximately to ten years old

On average; HVAC units last 10 to 15 years. If there have been double-digit shifts, the efficiency of the system blower motor for heating and cooling the operator’s home has diminished. Users may be able to lower their monthly electricity prices by using newer versions with higher efficiency ratings.

How often and when should HVAC blower motor be replaced?

  • The HVAC blower motor needs to be upgraded if the HVAC system makes an odd noise.
  • The HVAC blower motor ought to also be serviced if energy bills are rising arbitrarily.
  • After determining whether the air filter is unclean, the HVAC blower motor needs to be changed. Filters that are blocked make it harder for cold air to travel over heat exchangers, which leads to overheating and shutoff.
  • Once the air handler blower fan has been thoroughly cleaned, the HVAC blower motor should be replaced. Similar to clogged filters, dust on the air handler fan’s blades will reduce the passage of cold air across the heat exchanger.

What happens if HVAC blower motor is not replaced?

  • If the HVAC blower motor is not replaced, no airflow will occur in the system at all. Depending on the problem, blower motors can generate a variety of noises. A blower that is malfunctioning may produce strong screams, disturbances, and crunching.
  • The blower might overheat and ruin the entire system if the HVAC blower motor is not replaced.
  • A foul odour may emerge if the HVAC blower motor is not changed.

HVAC blower motor cleaning

The blower motor of the HVAC should typically be cleaned every 1-2 years, according to experts. Let us check out how clean the HVAC blower motor is.

For HVAC blower motor cleaning, a brush and a vacuum are required. To clean the fan blades, motors assembly, and raccoon cage, the brush would have to be clean sufficient to allow access to them. The bower cabinet will be cleaned and the dust removed by vacuums.

The HVAC unit coils should be cleaned at least once per year to minimize the energy consumption and lower power expenses. Evaporator and condenser coils that are unclean are thought to use more energy than 30% more than customary.

When to clean HVAC blower motor?

  • The blower motor for the HVAC system needs to be cleaned when dirt and dust accumulate. Clean the fan of any debris if user can, and then add a quality air filter. If not, speak with a specialist.
  • When in the HVAC unit has an excessive amount of moisture, the blower motor needs to be cleaned. In order to check if it can be dried out and fixed, user need to call a specialist.
  • If the HVAC blower motor has a faulty capacitor, it needs to be cleaned.
  • An HVAC blower motor must be swept when it ages.
  • When ducts are filthy or leaky, the HVAC blower motor should be cleaned.
  • It is necessary to clean the HVAC blower motor when the filter is blocked. Every three months replace a filter.

What will happen if HVAC blower motor is not cleaned?

If the HVAC blower rotor is not cleaned the fan wheel gets grit or oils. It can let the tires spin more slow and limit how much air the blower motor can flow all around room. The blower will have to work harder for any dirt or all those blades. So little air is compressed and more amps are pulled.

HVAC blower motor types and Cost, application

When to turn the blower motor on or off is controlled by the thermostat. Let us look at the prices and types of HVAC blower motors.

Different types of HVAC blower meterRespective priceVoltageSpeedTypeApplicationPhaseFrequency
1. AC 75 Watt HP single shaft blower motor2500240 V2000 – 6000 RPMAlternative currentAutomobile industrySingle phase50 Hz
2. Mild steel flame proof blower motor30000415 V1000 – 2000 RPMAlternative currentIndustrialSingle phase50 Hz
3. Mother single phase long shaft blower motor4200220 V2800 RPMAlternative currentSquirrel cage induction motorSingle phase50 Hz
4. AC blower motor3300220 – 240 V1200 RPMAlternative currentBlowerSingle phase50 Hz
5. External rotor motor blower3500220 – 415 V1425 – 2800 RPMAlternative currentIndustrialSingle phase50 Hz
6. Steam blower motor2900280 – 320 V1201 – 1300 RPMAlternative currentIndustrialThree phase50 Hz
7. Single phase CE blower motor4950< 115 V1000 – 1100 RPMAlternative currentIndustrialSingle phase50 Hz
8. Blower motor4500380 V1050 RPMAlternative currentIndustrialSingle phase50  Hz
HVAC blower motor uses in different types of HVAC and their respective features and respective price

HVAC blower motor wiring diagram

The most effective and adaptable blower motor is one that uses an electronically commutated motor (ECM). Let us look at the wiring diagram for the HVAC blower motor.

Image – HVAC blower motor wiring diagram

Compared to PSC motors, ECMs are typically 80% more efficient.

How to wire HVAC blower motor?

The stress that HVACV technicians face is a result of a number of factors, including the working environment and lengthy workdays. Let us examine the HVAC blower motor’s wiring.

  • Ensure the power is turned off and discharge any capacitors by shorting off their terminals.
  • The capacitor will discharge each time a user switches on the power and then turns it off and back on.
  • If there is no connector, a substitute motor can typically be made with the same colors by connecting the wires according to color. Look at the schematics, which is often geld to the inside of the blower door, if the wire colors don’t match. The wire colors will be labelled on the motor when it arrives.
  • When in doubt, run the furnace at high speed and the HVAC at medium speed. Naturally, if the furnace wire harness includes a connector, it must be clipped out so that there is as much wire as feasible.
  • The user must be aware of the purpose of each terminal on the furnace if they are plugging straight into spade terminals.
  • To connect the wires, use wire nuts, and to prevent extra wire from being drawn into the blower, tie it off with a wire tie.
  • Make certain the motor is spinning in the appropriate direction. Otherwise, the majority of replacement motors have reversing wire hidden beneath a cover plate.

HVAC technicians have physically hard jobs. A range of mental and physical obstacles might arise when working in confined, unclean, and gloomy spaces.

When HVAC blower motor does not work?

The heat exchanger, blower motor, condenser, evaporator, and combustion chamber are a few critical parts of the HVAC system. Let us see the motor of the HVAC system when it fails.

  • The HVAC blower motor does not work if the fan does not start in an orderly manner. The fan would just not turn on when there was a problem with the HVAC system’s wiring or motor.
  • If the HVAC unit has a broken thermostat, the blower motor will not operate.
  • If the condenser and evaporator contain too much moisture, the HVAC blower motor need not activate.


This article covers a variety of topics, including what an HVAC blower motor is, how it operates, where it is located, how big it is, how much it costs, how it is used, how to repair an HVAC blower motor, how to clean an HVAC blower motor, and much more.