What This Error Means

Goodman error code E5 on applicable GMVC96/GCVC96 furnaces indicates an open fuse in the low-voltage control circuit. This fuse helps protect the furnace control components from electrical faults. When it opens, the thermostat or furnace controls may stop functioning normally.

Symptoms You May Notice

The furnace may fail to start or respond to a call for heating. The thermostat may display a battery-power message, and the furnace control board may display E5. Depending on the installation, other control functions may also be affected.

Common Causes

A short circuit in the low-voltage thermostat wiring is a possible cause. Damaged insulation, pinched wires, or a fault in a connected low-voltage component may cause the protective fuse to open. The underlying electrical problem must be identified before the furnace is returned to service.

Safe Troubleshooting Steps

Check the thermostat display and note any error messages. If the furnace displays E5, turn the system off and contact a qualified HVAC technician. A technician can inspect the low-voltage wiring, identify the cause of the open fuse, and replace it with the manufacturer-specified type and rating after correcting the fault. Do not bypass the fuse or repeatedly replace it without diagnosing the cause.

Parts Commonly Involved

Low-voltage control wiring, thermostat wiring, control-board fuse, and potentially connected low-voltage components. The applicable service documentation specifies a 3-amp automotive-type fuse.

When to Call a Technician

Call an HVAC technician if the error persists after completing the recommended basic troubleshooting steps or if the system repeatedly locks out.

Safety Notice

Disconnect power before inspecting the equipment. Never bypass safety devices or operate the system if you suspect unsafe conditions.

Manufacturer Documentation