E8 High-stage pressure switch closed at start of heat

What the control is telling you

The high-stage pressure switch is already closed when heat starts. The furnace runs on low stage only.

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

Likely causes

• High-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. Check the high-stage switch with a meter with the inducer off. It should be open.
3. Replace a stuck switch with the correct part.
4. Repair any short in the wiring.

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

• 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
• E4 Flame sensed with no call for heat
• E5 Control fuse open
• E6 Low flame signal
• E7 Igniter circuit fault
• E9 High-stage pressure switch will not close