Goodman GMVC960803BN Error Code Eb6: Over/Under Voltage Trip or Over Temperature Trip

What Does Code Eb6 Mean?

The GMVC960803BN drives a variable-speed ECM blower whose power module contains its own protection electronics. Eb6 is set when that module shuts the motor down for one of three reasons: line voltage above about 140VAC, line voltage below about 70VAC, or an over-temperature condition inside the power module itself. The protection exists because the motor electronics can be damaged if they are asked to run outside their voltage or temperature limits.

This is different from the other Eb faults around it. It is not a wiring or no-run fault like Eb0, a communication loss like Eb1, or a jammed rotor like Eb5. Eb6 is the motor protecting its own power electronics from the electrical supply or from heat. Because it can be triggered by a transient, the motor may restart automatically once conditions return to normal, which is why an occasional Eb6 during a storm or a brief brownout can clear on its own.

When Eb6 recurs, the cause is usually persistent. High or low incoming line voltage points to a supply problem in the home or from the utility, and a failing neutral or a heavily loaded shared circuit can push voltage out of range. The over-temperature path points to a hot, poorly ventilated furnace location, blocked clearances around the unit, or a failing power module. High ambient temperature around the furnace is a specifically listed cause.

What You'll Notice

• The blower stops and the furnace quits delivering heat, sometimes clearing and running again on its own
• The 7-segment display shows Eb6
• The problem lines up with power events such as storms, brownouts, or large appliances cycling on the same service
• The furnace or mechanical closet is noticeably hot or poorly ventilated when the fault occurs
• Repeated shutdowns during the hottest part of the day or under heavy electrical load in the home

Common Causes

How This Is Diagnosed

A technician has an electrician or themselves measure the line voltage at the furnace disconnect and compare it to the range on the furnace rating plate, since high or low supply voltage is the leading cause. They look for a failing neutral or an overloaded shared circuit if voltage is out of range. For the over-temperature path they assess the furnace location for high ambient heat, blocked clearances, or inadequate ventilation, and then test the motor's power module. If voltage and environment are both normal and Eb6 persists, the ECM motor module is the likely failure. This is informational; voltage testing and motor replacement are professional, line-voltage tasks.

When to Call a Professional

This code involves components that are not homeowner-serviceable, so have a licensed HVAC technician diagnose and repair it. Keep in mind:

• Eb6 keeps returning rather than clearing after a single power event
• Home line voltage is suspected to be high or low, or a failing neutral or overloaded circuit is possible
• The furnace location runs hot or is poorly ventilated and the over-temperature trip keeps recurring
• Voltage and ambient temperature are confirmed normal but Eb6 persists, pointing to a failed power module

✓ Verified against manufacturer service manual — March 2026