Goodman, Amana, Daikin GMVM96 error code b3
Blower motor running in power, temperature or speed limit
Goodman is the platform name, and your unit may not say it
Amana AMVM96 / ACVM96, Daikin GMVM96 platform are the same board with a different badge, so this page covers all of them. The fault, the checks and the parts are identical, which is why there is one page rather than one per brand.
Quick answer
On Goodman GMVM96 (2010s), b3 is a fault. It means blower motor running in power, temperature or speed limit. A first thing to check: Motor overloaded because airflow is restricted, so it runs hot.
- Applies to
- Goodman GMVM96
- Goodman and Amana GMVM96, GMVM97, GCVM96 alphanumeric codes · Furnace · 2010s
- Type of code
- Fault
- Urgency: Needs attention soon
- First safe check
- Check the filter and the return air grille. A restricted system makes the motor work harder and run hot.
What b3 means on this model
The blower is running and the control has it in a protection state: too hot, too fast for the current demand, or outside the speed it should be using. This is the control limiting the motor rather than letting it run into something that would damage it.
Symptoms you will notice
- Blower runs but furnace does not heat properly
- Blower sounds like it is running too hard for the mode
- Code appears during a heat or cool call
Common causes
The code tells you what the control detected, not which part failed. These are the causes we see most often, roughly in order of likelihood:
- Motor overloaded because airflow is restricted, so it runs hot
- Blower running at a speed the control did not request
- Failing motor drawing too much current
- Control board output fault
What you can safely check
These are homeowner-level checks. None of them need you to open a live electrical compartment or work on gas.
- Check the filter and the return air grille. A restricted system makes the motor work harder and run hot.
- Confirm the thermostat is not calling for a mode the board has not been configured for.
Do not do these
- ×Do not run a furnace with no filter or a dirty one to see if the code clears. That is how motors and heat exchangers get destroyed.
When to call a technician
Book a technician, do not keep resetting it
This fault will not clear on its own. Every power cycle gives the control one more failed attempt, and repeated attempts are what turn a cheap part replacement into a seized or contaminated system.
- This is a fuel-burning appliance, so treat anything involving a burner, gas valve or flue as technician work. If you smell gas at any point, leave the property and call the gas utility from outside rather than continuing to diagnose.
- If the appliance has stopped mid-cycle, is making a noise you have not heard before, or smells burnt, stop reading here and call. Those are symptoms of something the fault code does not describe well enough.
Filters and grilles are homeowner work. Everything else is technician work.
What it costs to fix
Parts
Motor $250 to $500. Filter $8 to $40. Control board $250 to $500.
Labor
One to four hours depending on the cause.
DIY or technician
Filters and grilles are homeowner work. Everything else is technician work.
Typical US part and labor ranges, 2026. They vary by region, model and contractor, so treat them as a planning figure, not a quote.
Scope of this code
- Code table
- Goodman and Amana GMVM96, GMVM97, GCVM96 alphanumeric codes
- Models in scope
- Goodman GMVM96, 2010s
- Checked
- Confirm on your own unit
- Find the model number on the data plate, then check this code in the service manual for that model. Manufacturers revise code tables between model years, and a revised board can renumber a fault.