What does Goodman Furnace Blower Won't Shut Off - Causes & Fix mean?

Most often caused by thermostat set to FAN ON or a short between R and G wiring. Set thermostat to AUTO or repair the wire short.

How do I fix Goodman Furnace Blower Won't Shut Off - Causes & Fix?

Follow the step-by-step diagnosis below. The most likely fix is identified by checking power, sensor resistance, and control-board signals in order — using a multimeter and the part numbers documented in the parts reference table.

Can I keep running the equipment with this fault active?

Generally no. Faults on Hvac units are emitted when a sensor, safety, or control circuit is outside its operating envelope. Running through an active fault risks compressor, heater, or control-board damage. Diagnose and clear the fault first.

What part is most commonly replaced for Goodman Furnace Blower Won't Shut Off - Causes & Fix?

The most frequently replaced parts for Goodman Furnace Blower Won't Shut Off - Causes & Fix are listed in the Parts Reference section of this guide with OEM part numbers and typical price ranges. Check the table for direct replacements.

Is Goodman Furnace Blower Won't Shut Off - Causes & Fix a DIY repair or do I need a technician?

Sensor swaps, fan motor replacements, and condenser cleaning are typical DIY-level repairs. Anything involving refrigerant, gas, or high-voltage (>240V) work requires a licensed technician for both safety and code-compliance reasons.

Goodman Furnace Blower Won't Shut Off - Causes & Fix

Goodman Furnace Blower Won’t Shut Off — What’s Happening

A Goodman furnace blower that won’t shut off is not usually a fault code by itself. It is a symptom caused by the thermostat, fan control logic, a stuck relay or board, or an airflow or safety fault that keeps the blower energized. The furnace is either being commanded on continuously or the control board is stuck sending blower power.

If your unit is actually displaying an 8-flash fault code, Goodman’s published service material says that means an igniter relay fault or a shorted hot surface igniter. Goodman also notes that open or insufficient grounding is the most common field cause when that 8-flash fault appears, especially at the blower motor ground and the low-voltage common ground.

Jump to Fix

Most Likely Causes

Thermostat fan set to ON The thermostat fan switch is set to ON instead of AUTO, or the thermostat circuit is calling for continuous fan operation.
Short between R and G wires A short between the R and G conductors in the thermostat wiring or a failed thermostat causes a constant fan demand.
Stuck blower relay on control board Welded or stuck blower relay contacts on the furnace control board or a failed fan relay keep the blower energized.
Open or insufficient grounding Poor grounding at the blower motor ground or low-voltage common ground can cause control faults and continuous blower operation, especially when an 8-flash fault is present.
Failed blower control module A failed blower control module on ECM-style motors can drive the blower continuously even without a command.
Safety switch or airflow problem Rollout, limit, restricted filter, or vent conditions can keep the furnace in a faulted state and drive continuous blower operation.

How to Diagnose and Fix

Verify the thermostat is set to AUTO (not FAN ON) and confirm whether the blower behavior changes when you remove or disconnect the thermostat.
With power off, check for a short between the R and G wires at the furnace terminal strip using a multimeter set to resistance (continuity between R and G with thermostat disconnected indicates a wiring fault).
Inspect the furnace control board for a stuck or welded fan relay or a board command that keeps the blower energized.
Check all ground connections on the furnace chassis, especially the blower motor ground and the low-voltage common ground, and tighten any loose or corroded connections.
Power-cycle the furnace by turning power off for 10 seconds and then restoring power to reset any control faults.
If the unit is displaying an 8-flash fault and grounding corrections do not resolve it, have a technician replace the hot surface igniter.
Inspect the blower motor and control module if the relay is not the cause (ECM modules can fail and require replacement).
Check the air filter, vent system, and any active safety switches if airflow or limit-related faults are suspected.

Parts You Might Need

Part	Notes
Thermostat	Amazon \| If the fan command is stuck or the thermostat is misconfigured or failing.
Furnace control board	Amazon \| If the blower relay contacts are welded or the board is failing to stop the fan command.
Blower motor control module	Amazon \| For ECM-equipped furnaces when the module fails and drives the blower continuously.
Hot surface igniter (HSI)	Amazon \| Required if the furnace is displaying the 8-flash fault after grounding issues are corrected.

If your appliance also shows a code on the display, these match this problem:

When to Call a Pro

Call a professional if you are not comfortable working with low-voltage wiring or if the problem persists after checking the thermostat and visible wiring. Control board diagnosis, ECM blower module replacement, and any work involving the hot surface igniter or gas burner system should be handled by a qualified HVAC technician. If the furnace is displaying an 8-flash fault code or if safety switches are involved, professional diagnosis is recommended to prevent further damage and maintain safe operation. For gas line, burner, or igniter work, or if you ever smell gas, stop and call a licensed technician.