Payne PG96VTA Error Code 23: Pressure Switch Did Not Open
What Does Code 23 Mean?
Code 23 (two short flashes followed by three long flashes) means the control expected a pressure switch to be open at a point in the sequence — for example before the inducer establishes draft — but the switch was already closed. A switch that will not open when it should is treated as a safety-interlock failure.
The pressure switches on this condensing furnace prove that the inducer is establishing proper draft through the heat exchanger and vent. If the switch is stuck closed, or the sensing tubing is obstructed so the switch cannot respond to pressure changes, the control can no longer trust the draft-proving interlock and flags code 23.
This is the counterpart to codes 31 and 32, which flag a pressure switch that did not CLOSE when it should have. Code 23 is the opposite failure mode — stuck closed rather than failing to close — on the same draft-proving system, and like the others it is diagnosed by a technician rather than the homeowner.
What You'll Notice
- The furnace fails to start its normal ignition sequence, or halts early in the cycle
- The amber LED flashes two short flashes followed by three long flashes (code 23)
- No burner ignition and little or no heat
- The problem may be intermittent if the tubing is partially obstructed or the switch sticks occasionally
- The inducer behavior may seem out of step with the rest of the startup
Common Causes
| Cause | Likelihood | DIY? |
|---|---|---|
| Obstructed pressure tubing | Most common | ✗ Call a pro → |
| Pressure switch stuck in the closed position | Common | ✗ Call a pro → |
How This Is Diagnosed
A technician checks the pressure-switch sensing tubing for obstruction, kinks, or moisture, and then tests the switch itself to see whether it is mechanically stuck in the closed position. The switch contacts should be open at rest and only close once the inducer establishes draft.
Because this involves the combustion draft-proving system, the condensate side, and possible switch replacement, it is professional work. There are no safe homeowner steps beyond confirming the furnace has power and a heat call before calling a technician.
When to Call a Professional
This code involves components that are not homeowner-serviceable, so have a licensed HVAC technician diagnose and repair it. Keep in mind:
- The furnace will not begin ignition and shows code 23
- The code is intermittent, suggesting tubing that is partially blocked or a switch that sticks
- The furnace was recently serviced and the pressure tubing may have been disturbed
- Code 23 appears alongside other pressure-switch codes such as 31 or 32
Frequently Asked Questions
What does code 23 mean on my Payne PG96VTA?
It means a pressure switch that should have been open was found closed — usually because the sensing tubing is obstructed or the switch is stuck closed. It needs an HVAC technician to inspect the tubing and switch.
Is code 23 the same as codes 31 or 32?
No. Codes 31 and 32 mean a pressure switch failed to close when it should have; code 23 is the opposite — a switch that failed to open. All three involve the same draft-proving system but different failure modes.
Can I fix a stuck pressure switch myself?
No. Diagnosing and replacing a pressure switch or clearing its sensing tubing is professional work on the combustion safety system and should be left to a technician.
✓ Verified against manufacturer service manual — March 2026