Goodman furnace EC: Inducer motor overcurrent
EC means the draft inducer is drawing more current than it should. Either the motor is failing, or something is making it work harder than it was designed to.
Applies to: Goodman GMVM97 and GCVM97 and Amana AMVM97 modulating gas furnaces with a two-character alphanumeric display.
What it means
The control monitors the inducer's current draw and reports EC when it exceeds the expected range. A motor pulls excess current for two broad reasons: it is failing mechanically — worn bearings, a seizing shaft — or it is being asked to do more work than normal, which for an inducer usually means moving air against a restriction. That second case is the one worth holding onto, because it means EC and the pressure switch codes can share a root cause. A partly blocked vent makes the inducer labour, and depending on which limit is reached first, the furnace may report the restriction as a draft-proving failure or as an overcurrent.
Most common causes
- Worn inducer motor bearings, or a motor approaching failure.
- A restricted vent or intake making the motor work against back pressure.
- Debris in the inducer housing or a damaged inducer wheel.
- A wheel that has come loose on the shaft.
- Low supply voltage, which raises current draw for the same work.
- A failing motor capacitor where one is fitted.
- A control board misreading the current.
How to diagnose it
- Listen to the inducer. Grinding, rattling, or a noticeably louder run than usual points at the motor or the wheel.
- Check the outside vent termination for restriction, since that can cause this as well as the pressure switch codes.
- Note whether pressure switch faults have also appeared. The two together strongly suggest a restriction rather than a failing motor.
- Note whether the house has had voltage problems or the fault coincides with other electrical symptoms.
How to fix it
- Clear the vent termination if it is blocked — homeowner work, and worth doing before anything else.
- The inducer motor, its wheel, and its housing are technician work.
- Have the vent checked properly if the motor is replaced. Fitting a new inducer into a restricted vent system will simply wear the new one out too.
- Do not keep resetting a furnace that reports this. A motor drawing overcurrent is heating up, and the code exists to stop that continuing.
Notes
Because a restriction can present either as an overcurrent or as a draft-proving failure, it is worth mentioning both codes to a technician if both have appeared. They may well be one fault seen from two angles.
Related
All codes for this manufacturer
Goodman and Amana furnace fault codes — every code, with what differs between models.