Amana furnace code b4: Motor Trips
Professional repair
What does b4 mean on an Amana furnace? The ECM motor sensed a loss of control or became overloaded and shut down.
Before you touch anything: the six signs that mean stop troubleshooting and call a pro →
Motor and load diagnosis. DIY part cost: $400–800 — a pro visit for this class of fault typically runs $150–350.
What causes it (in order of likelihood)
- Motor overload / control loss TECH
Parts referenced by this code
Always match parts against your model's parts list — part numbers vary within a series.
Questions about this code
What does b4 mean on an Amana furnace?
The ECM motor sensed a loss of control or became overloaded and shut down.
How do I fix Amana furnace code b4?
There's no safe homeowner fix; motor and load diagnosis is technician work. Note when it happens and what the furnace was doing.
How much does it cost to fix Amana furnace code b4?
Cost depends on what caused the overload or loss of control. A technician's motor and load diagnosis is needed before you can get a repair quote.
Applies to
AMVC96 · ACVC96
Different Amana generations use different code maps. If your series isn't listed, don't assume this meaning — check your blower-door label.
Same control platform, same code: Goodman furnace code b4
Verified against Goodman GMVC96/GCVC96 Service Manual, p.45
Amana AMVC96/ACVC96 furnaces use the same control board and code map as the Goodman GMVC96/GCVC96 — the cited Goodman service manual is the platform document for both brands.
Last verified 2026-07-06 · page updated 2026-10-03 · how we verify
Related Amana furnace codes
These codes use the same dual 7-segment display (two-stage variable-speed) system.
| Pattern | Meaning |
|---|---|
| b3display b3 | ECM Motor in a Limiting Condition (b3) |
| ONdisplay ON | Display Reads ON — Normal |
| b2display b2 | Motor Horsepower Mismatch (b2) |
| b1display b1 | ECM Motor Communications Lost (b1) |