Quick summary
Match what you notice to a safe next step
These observations can narrow the starting service, but they do not confirm which part has failed.
What you notice
Indoor blower motor is not running
What it may point to
The furnace or air handler can be powered but unable to push any air, so every supply register stays still even though the thermostat is set correctly.
Safe next action
Note when the change began and whether the system is running
What you notice
Failed blower capacitor, fan relay, or control board output
What it may point to
The system is being told to move air, but the electrical component that starts or energizes the blower is not doing its job.
Safe next action
Compare nearby rooms and keep vents open
What you notice
Thermostat, low-voltage wiring, or fan setting problem
What it may point to
If the thermostat is not actually calling for the indoor fan, the equipment may sit idle and the vents will feel dead throughout the house.
Safe next action
Record any code, sound, smell, or weather event
What you notice
Closed dampers, collapsed flex duct, or a disconnected main trunk
What it may point to
Air can be produced at the equipment but blocked or dumped before it reaches the rooms, sometimes affecting one zone and sometimes nearly the whole home.
Safe next action
Check the filter and arrange an evaluation if it persists
Safe things to check
- Confirm the thermostat mode and setpoint
- Inspect the air filter and replace it if visibly dirty
- Make sure visible supply and return vents are open
Do not attempt
- Do not open sealed electrical or equipment panels
- Do not bypass a safety switch or force repeated restarts
A few quick questions
Refine the best next step
Question 1 of 3
- 1How much of the home is affected?
- 2What is the system doing right now?
- 3When did this begin?
What this symptom can mean
Use the evidence you can observe
What no air from the vents usually points to
This symptom is about air movement, not air temperature. If you put your hand at a supply register and feel nothing at all, the problem is usually that the indoor blower is not moving air, or the air is being stopped before it reaches the vents. That is different from weak airflow, noisy ducts, dust from vents, or one isolated dead room, because here the key clue is total or near-total lack of air movement.
How to narrow down the cause from what you can observe
Set the thermostat fan to ON instead of AUTO and wait a minute or two. If no vents in the home start moving air, the issue is more likely at the blower, capacitor, relay, control board, thermostat signal, or power to the indoor unit. If one floor, one room, or one zone has no airflow while other vents still blow normally, a stuck zone damper, disconnected branch duct, crushed flex duct, or closed balancing damper becomes more likely than a failed blower.
The timing also matters. If the problem began suddenly, electrical failures such as a capacitor, relay, board, thermostat failure, or a tripped breaker are common. If it worsened gradually, a blower motor failing under load, a coil freezing from restricted airflow, or duct sections sagging, separating, or collapsing are more typical patterns.
What a service visit usually includes
A technician will usually verify the thermostat call, check whether the indoor unit has power, and determine whether the blower is receiving the command to run. From there they may test the blower capacitor, relay, motor amperage, and control board output, then inspect the supply plenum, accessible duct runs, and any zone dampers for blockages or disconnections. If icing is suspected, they may look at the evaporator coil and confirm whether airflow stopped first or the coil froze first.
What affects repair cost for this symptom
Cost depends heavily on whether the problem is electrical at the air handler or furnace, or physical in the duct system. A diagnostic visit is often followed by repairs such as a capacitor replacement, blower relay or board repair, blower motor replacement, reconnecting a detached duct, replacing collapsed flex duct, or correcting a failed zone damper. Typical 2025-2026 US repair ranges are roughly $167-$617 for a capacitor, $167-$617 for a relay or contactor-type control component, $592-$1,400 for a blower motor, $300-$1,250 for accessible duct repairs, and $388-$963 or more for zone damper work depending on access.
When to turn the system off
- Stop if you smell gas, see smoke or sparks, or hear a carbon-monoxide alarm
- Stop if water reaches powered equipment or a breaker trips again
- Stop if loud grinding, booming, or heavy ice appears
When to call for help
- Call when the symptom continues after the safe checks
- Call promptly when comfort is lost for the whole home
- Describe when it started and any water, ice, noise, odor, alert, or breaker activity
Cost guidance
What could this cost to fix?
Price depends on the actual cause, equipment, access, and local labor. Compare the national ranges in the Duct Repair Cost guide, or check service availability for your system.
Find local help for Ductwork Repair
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Browse HVAC help by stateFrequently asked questions
No air is coming from the vents: common questions
Why is my AC or furnace running but no air is coming out of the vents?
If no air is coming from any vent, is it more likely the blower or the ductwork?
Why would one zone have no airflow while the rest of the house is fine?
Can frozen AC coils cause no air from the vents?
How long does it usually take to fix a no-airflow problem?
Sources and review standard
Last updated July 18, 2026. Last reviewed July 18, 2026. HVAC Rescue reviews problem pages for homeowner-safe boundaries, service routing, source quality, and unsupported claims. No named technical reviewer is shown unless a qualified HVAC reviewer has completed that review.
