E4 Flame sensed with no call for heat

What the control is telling you

The control sees flame when the gas valve should be closed. Inducer and blower both keep running. ComfortNet thermostat shows IMPROPER FLAME E4.

Applies to: GMVC95/AMVC95 upflow and *CVC9 counterflow two-stage furnaces

Likely causes

• Flame sensor or its wire shorted to ground
• Burner flame lingering after shutdown
• Gas valve slow to close

Test and repair steps

1. Safety gas work by a licensed gas technician only. Shut the gas off before opening any gas fitting.
2. Look at the burners after the call ends. If flame stays, shut the gas off at the manual valve.
3. Check the flame sensor and its wire for a short to ground and fix it.
4. If flame lingers or the valve closes slowly, replace the gas valve.

Settings for these units

• Normal status displays (7-segment) · Goodman/Amana GM9S96/AM9S96
• Normal status displays (7-segment) · Goodman/Amana GM9S80/AM9S80
• Normal status displays (7-segment) · Goodman/Amana GM9C96/AM9C96
• Minimum recommended filter size · Goodman/Amana GM9C96/AM9C96

Models that show this code

10 models in Goodman/Amana *MVC95/*CVC9 two-stage ComfortNet

Other codes on the same units

• E0 Lockout - ignition failed 3 times
• E1 Low-stage pressure switch closed at start of heat
• E2 Low-stage pressure switch will not close
• E3 High limit or rollout limit open
• E5 Control fuse open
• E6 Low flame signal
• E7 Igniter circuit fault
• E8 High-stage pressure switch closed at start of heat