HVAC Error Code H6 — What It Means & How to Fix It

What Does This Error Mean?

HVAC error H6 means the indoor blower fan has stopped running or is running at the wrong speed. This is a critical error — without the indoor fan, the system cannot move air and the evaporator coil will freeze solid. The system will shut itself down to prevent damage until the fan issue is resolved.

Affected Models

Split System Air Conditioners
Mini-Split Systems
Central Air Conditioning Units
Ducted Heat Pump Systems

Common Causes

The indoor blower fan motor has failed or seized and is no longer spinning
The fan capacitor has failed, leaving the motor without enough starting voltage
The fan speed control board or PCB has a fault and is not sending the correct signal to the motor
Debris or a foreign object has jammed the fan blade, preventing it from turning
The indoor unit power supply has a blown fuse or tripped breaker cutting power to the fan

How to Fix It

Turn the system completely off at the thermostat and at the breaker. Do not keep trying to run the system — operating without the indoor fan will freeze the evaporator and can damage the compressor.

H6 is a protective shutdown. The system is doing the right thing by stopping.
Check the circuit breaker for the indoor air handler. Find the breaker labeled 'Air Handler' or 'Furnace' in your electrical panel. Reset it if it has tripped.

If the breaker trips again immediately after resetting, there is a serious electrical fault — call a technician.
Check the indoor unit for a local disconnect switch. Many air handlers have a small on/off switch on or near the unit. Make sure it has not been accidentally switched off.

This switch is often located inside the panel covering the air filter.
With the power completely off, open the indoor unit's access panel and visually check the fan blade for visible obstructions — leaves, insulation, or small debris can jam the fan.

Only do this if you are comfortable doing so and the power is confirmed off. Do not touch wiring or circuit boards.
If the breaker is fine, the switch is on, and there is no obvious jam, call an HVAC technician. The motor, capacitor, or control board will need to be tested and likely replaced.

A blower motor replacement typically costs $300 to $600 including labor.

When to Call a Professional

H6 almost always requires a professional repair. A failed blower motor, capacitor, or control board must be replaced by a licensed HVAC technician. Do not attempt to reach inside the indoor air handler while power is connected — high-voltage components are present.

Frequently Asked Questions

How do I know if my indoor fan is actually running?

Stand near a supply vent in your home when the system should be running. If you feel no air coming out, the indoor fan is likely not running. You can also hear the blower fan as a steady hum from inside the air handler when it is working.

What is a fan capacitor and why does it fail?

A capacitor is a small cylindrical component that gives the fan motor an extra boost of power to start spinning. Capacitors are common failure points — they wear out over 5 to 10 years, especially in hot climates. A failed capacitor often causes the motor to hum but not spin.

Is H6 going to damage my system if I do not fix it quickly?

If the system is left running without an indoor fan, the evaporator coil will freeze solid within minutes. This puts strain on the compressor and can lead to a costly compressor failure. The system's automatic shutdown is protecting you — get the fan repaired as soon as possible.