Goodman Furnace 3 Flashes: Pressure Switch Stuck Open
On a Goodman furnace with one diagnostic LED, three flashes means the pressure switch circuit has not closed. That is the *MES80, *MSS9* and GMH95: their charts read "Pressure switch circuit not closed. Induced draft blower is operating.", and the flash lists call it "Pressure Switch stuck Open" (*MES80) and "Pressure switch stuck open" (*MSS9*). The *MEC96 is different because its LED has three colours. Red three flashes is "Low fire pressure switch stuck open", but amber three flashes is "W2 call present without W1", a thermostat-signal fault with nothing to do with the pressure switch. Check the colour before you go further.
| Code | 3 flashes (Pressure switch stuck open) |
|---|---|
| Applies to | Single-LED Goodman series *MES80, *MSS9* and GMH95, and the three-colour *MEC96 (red 3 only); display series show the same fault as EE2 / EE9 or E2 / E9 |
| Severity | Unit will not run |
| DIY | Check, then call — owner-level checks first, then a dealer |
| Last checked |
What do 3 flashes mean on each Goodman series?
On every single-LED Goodman series in this site's set of manuals, three flashes is the pressure switch, and the induced draft blower keeps running while the furnace does nothing else. The table gives each manual's wording as printed, newest revision first, with the older *MES80 revision included because it said more.
| Series | Manual, revision, page | Goodman's wording (verbatim) |
|---|---|---|
| *MES80 / *CES80 | IOG-2021G (08/2021), flash code list p. 25 | Pressure Switch stuck Open |
| *MES80 / *CES80 | IOG-2021G (08/2021), chart p. 29 | • Pressure switch circuit not closed. • Induced draft blower is operating. |
| *MES80 / *CES80 | IOG-2021A (05/2019), chart p. 32 (earlier revision) | •Pressure switch circuit not closed. •Induced draft blower is operating. •If installed, manual reset limit switch is open on Masonry Vent Kit (MVK). |
| *MSS9* / *CSS9* | IOG-2009E (10/2015), flash code list p. 40 | 3 flashes, then pause: Pressure switch stuck open |
| *MSS9* / *CSS9* | IOG-2009E (10/2015), chart p. 42 | • Pressure switch circuit not closed. • Induced draft blower is operating. |
| GMH95 / GCH95 | IO-299P (10/2012), chart p. 42 | • Pressure switch circuit not closed. • Induced draft blower is operating. |
The symptom column of all three charts describes what you see in the same words: "Induced draft blower runs continuously with no further furnace operation." The small fan that pulls exhaust through the furnace is running, the burners never light, and the LED keeps repeating three.
The older *MES80 revision adds a third cause the newer ones dropped. IOG-2021A lists "If installed, manual reset limit switch is open on Masonry Vent Kit (MVK)", which applies only to an installation vented through a masonry chimney with that kit. Revisions D and G no longer mention it in the 3 FLASHES row.
On the *MEC96, check the colour first
The *MEC96 control flashes red, amber or green, and the same count means different things in different colours. Its chart (IOG-2011U, pp. 54–55) has three red rows about a pressure switch opening and one amber row with a count of three; only the first two red rows are a switch stuck open. Red two flashes is the opposite fault, "•Pressure switch stuck closed".
| LED signal | Goodman's fault description (verbatim) | Symptom as printed | Page |
|---|---|---|---|
| Red: Three repeating flashes | •Low fire pressure switch stuck open | •Furnace does not operate, three Red flashes on control board | 54 |
| Red: Three double flashes | •Second stage pressure switch stuck open | •Furnace does not operate, control board Red LED with three double flashes | 55 |
| Red: Six repeating flashes | •Pressure switch cycling lockout, pressure switch has opened 5 times in the same heating cycle | •Furnace does not operate, six Red flashes on control board | 55 |
| Amber: Three repeating flashes | •W2 call present without W1 | •Furnace does not operate, three Amber flashes on control board | 54 |
Amber three is a thermostat problem, not a venting one. The chart's corrective-action column for it reads "•Faulty thermostat or thermostat wiring or improperly connected thermostat wires", and the same chart's amber one-flash row ties W1 to the "low stage call for heat". Amber three means the control is getting the W2 signal without that W1 signal.
Pressure switch stuck open on Goodman furnace models with a display
Goodman furnaces with a display don't flash at all, but they report the same fault as a code, which is why "pressure switch stuck open" searches land on both kinds. The three-character series use EE2, and EE9 for the high-stage switch where there is one; the two-character *MVM96 and *MVM97 use E2 and E9.
| Series | Display | Goodman's wording (verbatim, first item of the cell) | Manual, page |
|---|---|---|---|
| *M9C96 / *C9C96 | EE2 | Low stage pressure switch circuit is not closed | IOG-2027B, p. 45 |
| *M9C96 / *C9C96 | EE9 | High stage pressure switch circuit is not closed | IOG-2027B, p. 45 |
| *MVC80 / *CVC80 | EE2 | Low stage pressure switch circuit is not closed | IOG-2023A, p. 34 |
| *MVC80 / *CVC80 | EE9 | High stage pressure switch circuit is not closed | IOG-2023A, p. 35 |
| *M9S96 / *C9S96 / *M9S92 | EE2 | Pressure switch circuit is not closed | IOG-2029A, p. 43 |
| *M9S80*U | EE2 | Draft Inducer pressure switch circuit is not closed; label p. 32: "Pressure Switch Open When Expected To Be Closed" | IOG-2031A, p. 28 |
| *MVM96 / *CVM96 | E2 | • Low stage pressure switch circuit is not closed.; code list: "LOW STAGE PRESSURE SWITCH STUCK OPEN" | IO-406E, pp. 52, 57 |
| *MVM96 / *CVM96 | E9 | • High stage pressure switch circuit is not closed.; code list: "HIGH STAGE PRESSURE SWITCH STUCK OPEN" | IO-406E, pp. 54, 57 |
| *MVM97 / *CVM97 | E2 | • Low stage pressure switch circuit is not closed.; code list: "LOW STAGE PRESSURE SWITCH STUCK OPEN" | IOG-2007E, pp. 56, 61 |
| *MVM97 / *CVM97 | E9 | • High stage pressure switch circuit is not closed.; code list: "HIGH STAGE PRESSURE SWITCH STUCK OPEN" | IOG-2007E, pp. 58, 61 |
Don't read EE1 as the same fault. On these controls EE1 (E1 on the *MVM series) is the opposite condition, a pressure switch that is closed when the furnace expects it open. The full code lists for every series are on the Goodman furnace codes hub.
What Goodman's charts list as possible causes
The single-LED charts each give a "Possible causes" column for three flashes, and they agree almost word for word. This is the *MES80 revision G list (p. 29), which matches the *MSS9* (IOG-2009E p. 42) and GMH95 (IO-299P p. 42) lists apart from punctuation.
| Possible causes, IOG-2021G p. 29 (verbatim) |
|---|
| • Pressure switch hose blocked, pinched or connected improperly. |
| • Blocked flue and/or inlet air pipe, blocked drain system, or weak induced draft blower. |
| • Incorrect pressure switch setpoint or malfunctioning switch contacts. |
| • Loose or improperly connected wiring. |
Every item on that list sits inside the furnace or in its venting, and the same chart row's notes begin "• Turn power OFF prior to repair." The corrective actions that go with it, from inspecting the pressure switch hose to correcting the switch setpoint, are written for whoever is doing that repair. Goodman's manuals assign installation and service to a qualified installer, service agency or the gas supplier.
What you can check yourself
Goodman's manuals give an owner very little to do on this code, and none of it is pressure-switch or vent repair. What they do leave to an owner is below, in the manuals' own words, with who each task belongs to.
| Task | Goodman's wording (verbatim) | Who |
|---|---|---|
| Note the colour and count | Red or amber matters on the *MEC96 ("three Red flashes" vs "three Amber flashes", IOG-2011U p. 54) | Owner: looking only |
| Filter | "Improper filter maintenance is the most common cause of inadequate heating or cooling performance. Filters should be cleaned (permanent) or replaced (disposable) every two months or as required." (IOG-2011U p. 52; IOG-2021G p. 26) | Not marked servicer-only |
| Burner flame | "Visually inspect the burner flames periodically during the heating season." (IOG-2011U p. 53) | Not marked servicer-only |
| Annual inspection | "The furnace should be inspected by a qualified installer, or service agency at least once per year." (IOG-2011U p. 52; IOG-2021G p. 26) | Installer or service agency |
| Condensate trap and drain (96 series) | "Condensate Trap and Drain System (Qualified Servicer Only)" (IOG-2011U p. 53) | Qualified servicer |
A clean filter will not close a pressure switch on its own; the filter is on the list because it is the one maintenance item Goodman leaves to the owner, and a technician will ask about it. If the furnace has been flashing three for more than one heating call, the useful thing to bring to the call is what you saw: the count, the colour on a *MEC96, and whether the inducer was running.
When to call a qualified servicer
- The LED keeps returning to three flashes, or a display furnace keeps showing EE2, EE9, E2 or E9.
- The *MEC96 shows red six flashes: Goodman's chart calls it a "Pressure switch cycling lockout, pressure switch has opened 5 times in the same heating cycle".
- Your furnace vents through a masonry chimney and has the Masonry Vent Kit the older *MES80 manual mentions.
- You smell gas, see soot or a disconnected vent pipe, or a CO alarm sounds: leave and call from outside, as below.
Goodman's safety wording
Each manual cited on this page prints the same gas-leak instruction near the front, including p. 3 of IOG-2021G, IOG-2009E and IOG-2011U, and p. 4 of IO-299P. Goodman also warns that improper repair can cause carbon monoxide, which is the reason this page stops at the filter.
| Goodman's wording (verbatim) | Source |
|---|---|
| "WHAT TO DO IF YOU SMELL GAS: Do not try to light any appliance. Do not touch any electrical switch; do not use any phone in your building. Immediately call your gas supplier from a neighbor’s phone. Follow the gas supplier’s instructions. If you cannot reach your gas supplier, call the fire department." | IOG-2021G, p. 3 |
| "Possible property damage, personal injury or death due to fire, explosion, smoke, soot, condensation, electrical shock or carbon monoxide may result from improper installation, repair operation, or maintenance of this product." | IOG-2011U, p. 3 |
Frequently asked questions
What does 3 flashes mean on a Goodman furnace?
On the single-LED *MES80, *MSS9* and GMH95, it means the pressure switch circuit has not closed while the induced draft blower runs. On a *MEC96 it depends on colour: red three is the low-fire pressure switch stuck open, amber three is a W2 call without W1.
Why is my Goodman furnace inducer running but the burners won't light?
That is exactly how Goodman's single-LED charts describe three flashes: "Induced draft blower runs continuously with no further furnace operation." The control is waiting for the pressure switch to prove draft, and it never does, so it never moves on to ignition.
Can a dirty filter cause 3 flashes on a Goodman furnace?
A blocked filter is not on Goodman's list of causes for three flashes; the list is about the pressure switch hose, the flue and inlet pipes, the drain system, the inducer, the switch itself and wiring. Changing the filter is still the one task the manuals leave to an owner.
What is the Goodman code for a stuck-open pressure switch on a display furnace?
EE2 on the *M9C96, *M9S96, *MVC80 and *M9S80*U, with EE9 for the high-stage switch on the *M9C96 and *MVC80. The two-character *MVM96 and *MVM97 use E2 and E9, which their code lists name "LOW STAGE PRESSURE SWITCH STUCK OPEN" and "HIGH STAGE PRESSURE SWITCH STUCK OPEN".
Should I reset a Goodman furnace showing 3 flashes?
Goodman's charts give this code's corrective actions to whoever is repairing the furnace, and the row's first note is to turn power off before repair. On lockouts, the *MSS9* manual adds: "If the condition which originally caused the lockout still exists, the control will return to lockout." (IOG-2009E p. 39)