Goodman Furnace H6 Error Code: Meaning, Causes & Fix

Not a Goodman fault code — "H6" is the gas-heat status "gH" read upside down on an inverted seven-segment display. The suffixes owners report with it are inverted real codes from Goodman's troubleshooting chart: 033 is EE0 (ignition lockout) and 233 is EE2 (pressure switch circuit not closed) read the same wrong way up.

Two mirror-image mistakes meet in this code. Goodman's installation manual for the GM9S96/GC9S96 generation lists gH — "Gas heat – Single Stage Control" — among its status codes: normal operating narration, not a fault. Read a seven-segment display from the wrong side, as happens when a board or display ends up inverted in downdraft and reoriented installations, and every character flips: the g that already passes for a 9 becomes a 6, the H drops to the front, and gH arrives at the eye as "H6." That is why no Goodman fault chart contains H6 — while the manual's troubleshooting chart is full of EE-prefixed faults. The same flip explains the longer strings owners search for. Read upside down, Goodman's EE0 becomes 033, and EE2 becomes 233 — so a furnace reported as "H6 033" is most likely showing a gas-heat status next to, or alternating with, a genuine EE0 fault, and Goodman's chart defines EE0 precisely: "Furnace lockout due to an excessive number of ignition retries (3 total) — failure to establish flame, or loss of flame after establishment." A "233" suffix points at EE2: "pressure switch circuit is not closed," with the chart sending diagnosis to the pressure-switch hose, a blocked flue or inlet pipe, a blocked drain system, or a weak induced-draft blower. Decode the orientation first; then, if a suffix is really there, the chart fault it decodes to is the diagnosis.

What causes the H6 code on a Goodman furnace?

An inverted display orientation

The root cause of H6 itself. Seven-segment characters are not rotation-proof: viewed upside down, gH (gas heat status) reassembles as H6, and EE-prefixed fault codes reassemble as digit strings like 033 and 233. Furnaces whose boards sit inverted in the blower compartment invite exactly this misread.

If 033 is present — ignition retries exhausted (EE0)

Decoded, the suffix is Goodman's EE0 lockout: the furnace tried to establish flame three times and failed, or lit and lost the flame. That is ignition, gas supply or flame-proving territory — real faults with real causes, all of them inside the burner compartment and all technician work.

If 233 is present — the pressure switch never closed (EE2)

Decoded, the suffix is EE2: the control ran the inducer but the pressure switch circuit did not close to prove venting. Goodman's chart aims diagnosis at the switch hose, blockages in the flue or inlet-air pipe, a blocked drain system on condensing models, or an inducer too weak to pull the switch in.

A status misread as a fault in the first place

Half of every H6 report needs no repair at all: gH means the furnace is heating. Only the decoded EE suffix, when one is genuinely displayed, represents a fault — which is why the first fix for H6 is always to re-read the display from the board's intended orientation.

Checks to run before you replace anything

1. Re-read the display the other way up before anything else: photograph it, rotate the photo 180 degrees, and see whether H6 becomes gH and any digits become EE codes — that single step resolves most H6 reports.
2. Use the characters around it as orientation anchors: a healthy idle display reads IdL the correct way up; if your IdL looks wrong, you are reading the board inverted.
3. Match any decoded suffix against Goodman's chart meanings: 033 = EE0 (ignition lockout), 233 = EE2 (pressure switch circuit not closed) — and note which one you have, because they send diagnosis in opposite directions.
4. Owner-safe externals only: thermostat calling for heat, filter condition, the outdoor flue and intake terminations clear of snow, leaves and nests, and no standing water visible around a condensing furnace's drain.
5. Never jumper a pressure switch or a limit, and do not open the burner compartment: EE0 and EE2 both guard the firing sequence, and bypassing their proofs defeats the safety logic they exist for.

How to fix the H6 error code

1. Step one is decoding, not parts: establish the board's true orientation, read the display correctly, and work with the real code — gH alone needs no repair at all.
2. For a decoded EE0 lockout, a technician works the ignition chain in chart order — gas supply and pressure, igniter condition, flame establishment and flame sensing — because three failed retries is a symptom shared by all of them.
3. For a decoded EE2, the chart's list is the work order: clear or repair the pressure-switch hose, clear the flue and inlet piping, clear the condensate drain system, and prove the inducer is pulling its rated vacuum before the switch itself is condemned.
4. If the display is permanently mounted where it can only be read upside down, note the correct decoding in the furnace's paperwork; the board is reporting accurately and does not need replacement for being read backwards.

The part that usually fails: Pressure switch and ignition chain

The two real codes an H6 report can hide point at the two gatekeepers of the firing sequence: the pressure switch circuit (EE2), which must prove the vent path before ignition is allowed, and the ignition/flame-proving chain (EE0), which must establish and keep a flame. Both exist to stop the furnace firing under unsafe conditions, which is why their faults lock the furnace out instead of working around the problem.

How to reset / clear the H6 code

H6 itself needs no reset, because the status it misreads as — gH — clears itself when the heat call ends. The real codes hiding in the suffixes are different: an EE0 lockout is reset by cycling furnace power (switch or breaker) once the cause of the failed ignitions has been addressed, and a lockout that keeps returning is a diagnosis, not a reset routine — Goodman's chart frames the lockout as the end of three retries, and repeated resets simply buy three more. EE2 clears when the pressure circuit actually closes on a healthy call. The board also stores its fault history, which the manual's L6F display function lets a technician review and clear; clearing history never clears a live fault.

Goodman furnaces report faults as LED blink patterns on older boards and as alphanumeric codes on the 7-segment displays of newer (and ComfortBridge/Bluetooth) models. Codes clear when the fault ends and a heat cycle completes; lockouts need the cause fixed plus a power cycle at the furnace switch.

Why does the H6 code keep coming back?

H6 comes back as reliably as gH does — every heat call, forever — because it is the furnace's normal heating status seen from the wrong side. The decoded faults have their own recurrence logic: EE0 returns when an ignition or flame-sense weakness is still present, and EE2 is famous for cold-snap repeats, when a marginal drain blockage or a frost-narrowed flue termination tips a weak vent proof over the edge on the coldest nights.

How to stop H6 coming back

• An inverted display orientation: The root cause of H6 itself. Seven-segment characters are not rotation-proof: viewed upside down, gH (gas heat status) reassembles as H6, and EE-prefixed fault codes reassemble as digit strings like 033 and 233. Furnaces whose boards sit inverted in the blower compartment invite exactly this misread.
• If 033 is present — ignition retries exhausted (EE0): Decoded, the suffix is Goodman's EE0 lockout: the furnace tried to establish flame three times and failed, or lit and lost the flame. That is ignition, gas supply or flame-proving territory — real faults with real causes, all of them inside the burner compartment and all technician work.
• If 233 is present — the pressure switch never closed (EE2): Decoded, the suffix is EE2: the control ran the inducer but the pressure switch circuit did not close to prove venting. Goodman's chart aims diagnosis at the switch hose, blockages in the flue or inlet-air pipe, a blocked drain system on condensing models, or an inducer too weak to pull the switch in.

Retrieving stored fault codes on Goodman furnaces

Goodman boards keep the last faults readable via the display/LED, and newer models expose fault history through the CoolCloudHVAC app and the onboard menu. The fault chart on the blower door remains the authority — Goodman reused similar-looking codes across board generations.

Other Goodman furnace error codes

See the full list on the Goodman Furnace error codes hub.

Codes H6 gets confused with

F02 — Not a Goodman code — no Goodman furnace document defines 'F02'. Goodman furnaces report faults as counted LED flashes on the control board or, on communicating/modulating models, as E-codes (E0, E1, E2, E3 and family) on a character display; F02 appears in neither system, so this page explains Goodman's real code language and how to get the true code from your furnace instead of inventing a meaning for this one If a search result, a forum post or a copied list sent you here looking for a Goodman furnace 'F02' error, the honest starting point is that Goodman has never published one.

9H — Not a Goodman fault code at all — "9H" is the status display "gH" (gas heat, single-stage control) from the status-code table in Goodman's furnace installation manuals, with the seven-segment display's lowercase g reading as a 9. It means the furnace is running a heat call, and there is nothing to reset. This page exists because the display is genuinely confusing, so here is the documented picture.

5 Flashes — On Goodman's single-stage boards: flame sensed without the gas valve energised — the GMES80 wiring diagram prints it verbatim: '5 FLASHES = FLAME SENSE WITHOUT GAS VALVE [ENERGISED]'. On Goodman's two-stage boards the same count means something else entirely: open rollout switch or open control board fuse. The generation split is documented in the what — read it before acting on any of it. Goodman's 5-flash is the clearest example on this site of why the door chart, not the flash count, is the diagnosis.

Frequently asked questions

Related guides

Facts on this page were checked against manufacturer documentation: www.manualshelf.com · www.manualshelf.com · www.manualshelf.com · manuals.plus · iwae.com · www.goodmanmfg.com