Goodman Furnace F02 Error Code: Pressure Switch Stuck Closed

Quick Answer

Goodman F02 means the pressure switch is stuck in the closed position before the inducer motor runs. This is different from a pressure switch that fails to close - F02 fires because pressure is detected when it should not be. The most common cause is a clogged condensate drain line backing up into the pressure switch hose.

I see F02 most often during the first cold snap of the year when a condensate line's frozen solid or algae has turned the trap into a plug. The furnace checks the switch before it even tries to spin up the inducer, so an F02 lockout means the board thinks the fan's already running or the switch is physically shorted. Ignore it and you're not getting any heat until you deal with the drain or swap that switch.

GoodmanFurnaceSeverity: moderateDifficulty: intermediate82% DIY Success

Time to Fix

20–60 min

Difficulty

intermediate

Parts Cost

$8 – $40

Tools Needed

Phillips #2 screwdriver, Flathead screwdriver

What Does the F02 Code Mean?

When you call for heat, your Goodman runs a quick safety check. If it detects the pressure switch is already closed before the inducer fan gets power, it kills the cycle right there. Nine times out of ten, it's not a bad switch. It's water backed up in the tubing or a blocked condensate trap. Usually a $0 fix if you catch it early.

Most Likely Causes

Based on aggregated repair data, here is the probability breakdown for this error code:

Condensate drain line plugged or frozen40%

Pressure switch hose kinked, collapsed, or blocked24%

Cracked or damaged inducer housing creating false pressure reading22%

Pressure switch failed in closed position14%

Symptoms You May Notice

You hear the thermostat click, maybe a relay inside the furnace, and then absolutely nothing. No fan noise, no igniter click. Just silence.
The LED on the control board is flashing the F02 sequence. Count those flashes carefully because Goodman boards can vary in exactly how they display it.
The inducer motor never spins up at all. You'd normally hear that low hum start about 30 seconds after the thermostat calls for heat, and you're not getting it.
Water dripping from the bottom of the cabinet or pooling under the furnace, which tells you condensate is backing up somewhere in the drain path.

Can you reset a Goodman furnace to clear the F02 code?

Once you've cleared the drain or dried out the pressure switch hoses, cut power at the service switch or breaker for at least 60 seconds. That clears the lockout memory on the control board. Restore power, call for heat, and watch the board LED. If F02 comes back immediately before the inducer even tries to spin, you've still got a stuck switch or water inside the switch housing.

Tools Required for Diagnosis

Phillips #2 screwdriverFlathead screwdriverMultimeter with continuity modeWet/dry vacuum with hose attachmentFlashlight or headlampNeedle-nose pliersSmall bucket and towels for water

Diagnostic Checklist

Follow these steps in order. We start with the easiest external fixes before opening up the machine.

Replacement Parts

If your diagnostic testing proves the component has failed, you will need a replacement. We recommend OEM parts over aftermarket for water-handling components.

Part Name	OEM Number	Estimated Price
Pressure SwitchB1370187 · $20–$40	B1370187	$20 – $40
Condensate Drain Hose KitB1751711 · $8–$18	B1751711	$8 – $18

Frequently Asked Questions

What's the difference between F02 and E5 on a Goodman furnace?

F02 is a sequence error. The board sees the switch is already closed before it even tries to start the inducer motor. E5 is more of a general pressure circuit failure that usually shows up while the furnace is already trying to run. F02 is almost always a physical blockage like a frozen drain or water stuck in the pressure switch hose. E5 could be a weak inducer motor or a venting restriction, and honestly that one tends to be a pricier fix when the inducer's the culprit.

How do I clear a Goodman condensate drain?

Two-step approach. First, find the drain line where it exits the furnace and use a wet/dry vac to pull out any algae slugs or debris. Second, check the internal trap inside the furnace. You can usually pull those by loosening a couple of hose clamps. Rinse it in a sink until the plastic looks clear again. Don't use Drano or any chemical drain cleaner. It can melt the thin plastic tubing or damage the connections, and you'll end up with a bigger problem than what you started with.

Can I run my furnace with the pressure switch hose disconnected?

No. Don't do it. That pressure switch is what keeps your furnace from running if the vent gets blocked or the inducer fan dies mid-cycle. Leave the hose off and the furnace might fire, but it can't protect itself if exhaust stops venting properly. Carbon monoxide becomes a real risk at that point. Only disconnect the hose for a few seconds during diagnosis and never, ever walk away from the furnace with it off.

How much does it cost to fix a Goodman F02 error?

Honestly it depends on the root cause. If it's a clogged condensate trap, you're looking at $0 if you DIY it, or maybe $75-150 if you call an HVAC tech to come flush it. A new pressure switch is about $25-40 for parts, plus an hour of labor if you're having someone else do the swap. Worst case, if the inducer housing is cracked and needs replacement, that's $200-400 in parts alone. But most F02 calls I go on? It's the drain. Clear the drain, done.

Why does my Goodman furnace get F02 every winter?

Because your condensate drain line probably runs through somewhere cold, maybe an unconditioned garage or crawlspace, or it exits outside where it can freeze. Once it freezes once it'll freeze again every year at roughly the same temperature. The real fix is insulating the drain line through any cold sections, or rerouting it to drain into a floor drain inside the building. You can also grab a condensate drain line heater kit for about $30 at any HVAC supply house. They plug right into a nearby outlet and that's the permanent solution.

Related Goodman Furnace Error Codes

Code: HUBGoodman Furnace Error Codes: LED Flash Code Guide for GMVC and GMSS Series Code: F01Goodman Furnace F01 Error Code: Ignition Failure After 3 Attempts Code: E5Goodman Furnace E5 Error Code: Pressure Switch Error Code: RESETHow to Reset a Goodman Furnace and Clear Error Codes

Models Known to Experience F02 Errors

This repair applies to most Goodman furnaces with this error code. Common model numbers include:

GMVC96, GMSS92, GCVC96, AMVC96, ASST96, GMEC96, ACVC96, ASVC96

Written by

Raj Patel

HVAC & Water Systems Specialist · 15 years experience

Last verified for technical accuracy on March 14, 2026