E1 Low-stage pressure switch closed at start of heat

What the control is telling you

At the start of a heat call the low-stage pressure switch is already closed before the inducer runs. The furnace will not start. ComfortNet thermostat shows PS1 CLOSED E1.

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

Likely causes

• Low-stage pressure switch contacts stuck
• Short in the pressure switch wiring

Test and repair steps

1. Safety turn power off before working on the control or wiring.
2. Pull the wires off the low-stage switch and check it with a meter with the inducer off. It should be open.
3. If it reads closed, replace it with the correct part.
4. If the switch is open, look for a short in the harness to the switch and repair it.

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

• C2 High-stage cooling
• d0 No shared data on the control
• d4 Memory card data rejected
• E0 Lockout - ignition failed 3 times
• E2 Low-stage pressure switch will not close
• E3 High limit or rollout limit open
• E4 Flame sensed with no call for heat
• E5 Control fuse open