EE1 Pressure switch closed at start of heating cycle

What the control is telling you

At the start of a heat call the (low-stage) pressure switch circuit is already closed before the inducer runs. The control will not start the ignition sequence. Flowcharts call this code E1.

Applies to: Goodman/Amana/GMC gas furnaces, 9-speed ECM, 7-segment control. Two-stage 96%: AC9C96, AM9C96, GC9C96, GM9C96. Single stage 80%: VC9S80, VM9S80, AC9S80, AM9S80, GC9S80, GM9S80. Single stage 92/96%: VC9S96, VM9S96, AC9S96, AM9S96, AM9S92, GC9S96, GM9S96, GM9S92

Likely causes

• Pressure switch contacts stuck closed
• Short in the pressure switch circuit wiring (to another wire or to ground)

Test and repair steps

1. Turn off power, remove the wires from the pressure switch and check the contacts with an ohmmeter while the inducer is off - they must be open.
2. If the contacts read closed with no vacuum applied, replace the pressure switch (on two-stage furnaces this is the low-stage switch).
3. If the switch is open, trace the pressure switch circuit wiring for a short to another wire or to ground and repair it.
4. Reconnect, cycle the thermostat and confirm the code clears.

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