Goodman Furnace Pressure Switch Stuck Open – Meaning, Causes & Fix
Goodman furnace 'Pressure Switch Stuck Open' is a diagnostic fault displayed on Goodman and Amana gas furnaces (which share the same platform) when the control board detects that the pressure switch circuit remains open — that is, the switch has not closed to confirm adequate inducer draft — after the inducer motor has been running for the required startup period. Goodman furnaces communicate this fault through a blink code on the control board diagnostic LED (typically 3 blinks on most Goodman models) or as a text message on communicating thermostat displays. This fault is a safety lockout: without pressure switch closure, the control board will not open the gas valve. The most common causes are identical to other brands with this fault — blocked condensate drains, disconnected hoses, and flue obstructions are responsible for the majority of cases. This guide covers every cause and fix step. For related pressure switch faults, see our Carrier Furnace Error Code 31 guide and our Trane Furnace 3 Flashing Red Lights guide.
What it means
The pressure switch has not closed after the inducer motor started, meaning the furnace cannot confirm safe draft conditions. The gas valve is locked out.
Severity
HighCan you fix it yourself?
Partial — checking the condensate drain, pressure switch hose, and flue pipe are safe DIY steps. Pressure switch or inducer motor replacement requires a licensed technician.
Call a technician when
Contact a licensed HVAC technician if the fault persists after clearing the drain and inspecting hoses, or if the inducer motor sounds abnormal.
What Does Pressure Switch Stuck Open Mean?
Goodman gas furnaces (including Amana-branded models, which share the same control system) use a combustion air inducer motor and pressure switch to verify safe draft before allowing gas to flow.
The 'Pressure Switch Stuck Open' message means the switch's normally-open contacts have not closed after the inducer started. Possible causes:
1. Blocked condensate drain: On 80%+ AFUE models, water can back up from a blocked drain into the pressure switch port. On 90%+ models, blocked condensate drain is the single most common cause. 2. Disconnected or blocked pressure switch hose: The rubber hose between the inducer and the switch is off, kinked, or filled with water. 3. Weak or failed inducer motor: Not generating enough suction to close the pressure switch. 4. Blocked flue: Restricted exhaust or intake reduces draft below the switch's closing threshold. 5. Failed pressure switch: The switch contacts are stuck open and will not close regardless of draft conditions. 6. Dirty air filter: Severely restricted airflow starves the inducer of combustion air.
This fault is mechanically identical across brands — compare with Carrier Furnace Error Code 31 and Trane Furnace 3 Flashing Red Lights. On Goodman furnaces specifically, the condensate drain blockage is disproportionately common due to the drain trap design on their 90%+ models.
What Causes This Error?
- Condensate drain or trap blocked — water backing into the pressure switch port
- Pressure switch hose disconnected, cracked, kinked, or filled with condensate
- Inducer motor not reaching required speed due to bearing wear or capacitor failure
- Blocked flue exhaust or combustion air intake pipe
- Pressure switch contacts stuck open — failed switch
- Air filter clogged, severely restricting combustion airflow
- Condensate pump failed, allowing backup into the drain system
- Inducer housing cracked, reducing negative pressure at the switch port
How to Fix Pressure Switch Stuck Open
- 1
Identify the fault blink code. On a Goodman furnace, look through the sight glass in the access panel. Most Goodman models use a 3-blink pattern for pressure switch open faults. Confirm using the fault code chart printed on the inside of the furnace access panel door. Some Goodman communicating models display 'Pressure Switch Stuck Open' as text on a compatible thermostat or the HVAC system's service screen.
- 2
Clear the condensate drain and trap. On 90%+ efficiency Goodman models (the most common residential models sold in recent years), locate the condensate trap — a U-shaped plastic trap, often in the bottom of the furnace cabinet or mounted on the side panel. Disconnect the drain hose from the trap outlet and use a wet/dry vacuum to suction the line clear. Pour a small amount of water through the trap to verify it flows freely. This step alone resolves the majority of Goodman pressure switch stuck open faults.
- 3
Inspect and reconnect all pressure switch hoses. Power off the furnace. Open the cabinet and trace every small rubber or vinyl hose connected to the pressure switch(es) and the inducer housing. There may be one or two switches with individual hoses. Verify each hose is firmly attached at both ends and shows no cracks or kinks. On Goodman furnaces, the hose running from the bottom of the inducer housing to the pressure switch is particularly prone to collecting condensate — disconnect it, drain any water out, and reconnect.
- 4
Test the pressure switch with a manometer or multimeter. With the furnace powered on and the inducer running, an HVAC technician can measure the draft pressure at the switch port. However, a basic test accessible to a DIYer is to use a multimeter set to continuity mode: with the furnace off, test across the pressure switch terminals. A stuck-open switch reads no continuity regardless of whether suction is applied. A known-good switch should close (continuity) when you apply gentle suction via a piece of tubing. Replace the switch if it fails this test.
- 5
Check the flue and intake pipes. Go outside and inspect the PVC exhaust and intake pipes. Clear any birds nests, leaves, ice blockages, or collapsed pipe sections. Both pipes must be fully unobstructed on two-pipe systems. In cold climates, frost or ice at the pipe terminations is a frequent winter cause of this fault on Goodman high-efficiency models.
- 6
Listen to and inspect the inducer motor. After clearing the drain and hoses, restore power and start a heat call. The inducer should start within 30 seconds of the thermostat call. Listen for steady operation — grinding, excessive vibration, or a hum without rotation indicates a failing motor capacitor or bearing. A failed inducer run capacitor (a common Goodman failure) can cause the motor to start sluggishly and fail to reach the speed needed to close the pressure switch. Capacitor replacement is a low-cost repair but requires a licensed HVAC technician.
When to Call a Professional
Goodman furnace Pressure Switch Stuck Open that persists after clearing the condensate drain, inspecting all hoses, and verifying the flue indicates a failed inducer motor, a stuck-open pressure switch, or a cracked inducer housing. Contact your local Goodman dealer or HVAC contractor. Goodman parts are widely available through HVAC distributors. Pressure switch replacement costs $80–$200. Inducer motor replacement costs $250–$550. Goodman furnaces come with a 10-year parts warranty on registered units — check warranty status before purchasing parts out of pocket.
Can You Still Use the Device?
Do not operate the Goodman furnace while the Pressure Switch Stuck Open fault is active. This safety lockout prevents gas flow without confirmed safe combustion conditions. Bypassing or jumping the pressure switch is extremely dangerous and a carbon monoxide risk. Resolve the fault fully before resuming heating.
See Also
Official Resources
Related Error Codes
Disclaimer: This article is for informational purposes only and does not constitute professional repair advice. CodeExplain is not affiliated with Goodman or any other brand mentioned. Always consult a qualified technician for complex repairs.