How do you fix Goodman E8?

Clear a blocked condensate drain if that is present — reasonable homeowner work. The pressure switches, hoses, and wiring are technician work, for the same reason as every pressure switch fault: they prove safe venting. Full steps and safety notes are on this page.

Goodman furnace E8: High stage pressure switch closed at the start of the heating cycle

E8 is the high-fire counterpart of E1: the second-stage pressure switch was already closed before the inducer ran, when it should have been open.

Applies to: Goodman GMVC96, GMVM97, GCVC96, GCVM97 and Amana AMVC96, AMVM97 two-stage and modulating gas furnaces with a two-character alphanumeric display. Single-stage furnaces have no high stage switch and cannot produce this code.

What it means

A two-stage furnace carries two pressure switches, one per firing rate, because high fire moves considerably more combustion air and needs its own proof of draft. Both must sit open at rest, and the control checks both before starting. E8 means the high-stage switch was found closed at that check. The reasoning is identical to E1 — a switch stuck closed would prove a draft that does not exist — but the consequence differs slightly in practice: because the fault is in the high-stage circuit, a furnace may still be capable of low-fire operation, so the symptom can be reduced output rather than no heat at all.

Most common causes

The high stage pressure switch contacts have stuck closed.
The sensing hose to the high stage switch is pinched or kinked, trapping pressure.
Water in the high stage sensing hose or its pressure tap.
A short in the high stage switch wiring.
The low and high stage switches swapped during a previous repair — a specific and easily missed cause.
The wrong switch fitted, with a setpoint that does not match the model.

How to diagnose it

Confirm the furnace is genuinely two-stage or modulating. A single-stage model cannot produce E8.
Note whether the furnace still produces some heat. Low-fire operation continuing while high fire faults is characteristic.
Check whether the furnace was recently serviced, since swapped switches are a real cause and a quick check for a technician.
Check the condensate drain for standing water, which puts moisture where these switches sense.

How to fix it

Clear a blocked condensate drain if that is present — reasonable homeowner work.
The pressure switches, hoses, and wiring are technician work, for the same reason as every pressure switch fault: they prove safe venting.
Ask the technician to confirm the two switches are fitted the right way round if the furnace has been worked on recently.
Never jumper either switch. Both exist to stop the furnace firing into a flue that cannot carry the products away.

Notes

Because two-stage furnaces can often limp along on low fire, high-stage faults tend to be noticed when the weather turns rather than when they occur. The code is usually present for some time before the house stops keeping up.

All codes for this manufacturer

Goodman and Amana furnace fault codes — every code, with what differs between models.

Models this code appears on

From the manufacturer's per-model database. If your model is not listed, this code may not exist on your board, or it may mean something different — check the model page.

The same fault on other control families

E8 is E1 transposed to the high-fire circuit, and other two-stage controls draw the same distinction: Trane E33 is the stuck-closed report for the S9V2's second pressure switch, and ICP's eight flashes the equivalent in its gas-valve diagnostic set. Single-stage furnaces cannot produce any of these — one switch, one code — which is why the fault reads as unfamiliar even to owners who have met its low-stage sibling. The interlock logic is identical: a switch that should rest open, found closed before the inducer moved.

What the fix costs

Budget as for any pressure switch fault — $150–400 per the repair cost guide — with the second-stage location changing the diagnosis more than the bill: same switch economics, same welded-contact and blocked-tube suspects, one extra question about why the high-fire circuit specifically is affected. The quiet cost angle is completeness. A technician already connected to the furnace for E8 can verify the low-stage switch, the tubing runs, and the condensate path in the same session, and asking for that while the panels are off is how two-stage owners avoid paying a second call-out for the sibling fault a season later.

DIY or call a pro?

Professional — the diagnosis is a manometer conversation, and the switch in question guards the venting proof for the furnace's hottest operating mode. The homeowner file for this one: when did it start, does it appear at the start of every call for heat or intermittently, and was there recent service anywhere near the burner compartment or condensate system? Do not jumper the switch, and do not settle for a furnace that 'mostly works' on low fire while E8 stands — the fault does not limit output politely the way a stuck-open second-stage switch does; it is an integrity failure in a safety chain, and it deserves the same urgency as its low-stage twin.

What this looks like

From the outside, this usually shows up as the inducer spins up but the burners never fire — that walkthrough covers what to check in order, and when it stops being a homeowner job.

Sources

Goodman Manufacturing — Diagnostic Code Identification System (model-specific fault code lookup)

This site is a reference, not a substitute for a licensed HVAC technician. Gas appliances can leak carbon monoxide and cause fire. Anything involving gas lines, the heat exchanger, or the flame sensing circuit should be handled by a licensed professional. Pages are written with AI assistance from the sources listed on each page and checked against them before publishing.