Skip to content
(877) 565-3062
Carrier furnace status code · Sources read 2026-11-01

Carrier Furnace Code 23: Pressure Switch Did Not Open

If you smell gas or a CO alarm sounds, leave the home and call the gas utility or 911 from outside.

Code 23 means a pressure switch did not open when the furnace control expected it to. Carrier's guides list two causes to check, both inside the furnace cabinet: obstructed pressure tubing and a pressure switch stuck closed.

Talk to a contractor about your Carrier furnace code 23

Call (877) 565-3062

One call reaches a contractor registered for your ZIP; ask the fee and the arrival window.

HVAC Responder Editorial Team · Reviewed 2026-11-01 · Facts quoted from manufacturer documentation

HVAC Responder is an independent referral service and is not affiliated with or authorized by Carrier.

How code 23 looks on the furnace light

On these Carrier furnaces the status light shows code 23 as 2 short flashes, then 3 long flashes . Carrier’s 58MVP (Series 170 & 180), 58MVB, 58UVB troubleshooting guide (58-06T) explains the pattern:

EACH OF THE FOLLOWING STATUS CODES IS A TWO DIGIT NUMBER WITH THE FIRST DIGIT DETERMINED BY THE NUMBER OF SHORT FLASHES AND THE SECOND DIGIT BY THE NUMBER OF LONG FLASHES.

Codes differ between furnace generations, so match the series on your furnace’s rating plate to the guide below.

What Carrier’s guides say code 23 means, by furnace series

58CVA / 58CVX

Carrier’s 58CVA / 58CVX troubleshooting guide (TG-GFC80-02) lists code 23 as:

23 PRESSURE SWITCH DID NOT OPEN

Checks listed in the same guide:

  • Listed check: “Obstructed pressure tubing.”
  • Listed check: “Pressure switch stuck closed.”

58MVP (Series 170 & 180), 58MVB, 58UVB

Carrier’s 58MVP (Series 170 & 180), 58MVB, 58UVB troubleshooting guide (58-06T) lists code 23 as:

23 PRESSURE SWITCH DID NOT OPEN

Checks listed in the same guide:

  • Listed check: “Obstructed pressure tubing.”
  • Listed check: “Pressure switch stuck closed.”

59MN7A (Series 100)

Carrier’s 59MN7A (Series 100) troubleshooting guide (59MN7A-01T) lists code 23 as:

23 PRESSURE SWITCH DID NOT OPEN

Checks listed in the same guide:

  • Listed check: “Obstructed pressure tubing.”
  • Listed check: “Pressure switch stuck closed.”

Discuss your Carrier furnace code 23 with a contractor

Call (877) 565-3062

One call reaches a contractor registered for your ZIP; ask the fee and the arrival window.

Does code 23 reset on its own?

The guides do not describe an automatic reset for this code.

What to do before you call

  • Write the code down before you touch anything. Carrier’s 58MVP (Series 170 & 180), 58MVB, 58UVB troubleshooting guide (58-06T) starts with: “DO NOT REMOVE BLOWER ACCESS PANEL! Record status of AMBER LED.” Turning off power can also clear the code history.
  • Everything else on these lists (gas valve, pressure switches, wiring, venting, the control board) is technician work.
  • For code 23, report whether the indication appears before ignition begins. The manual entry concerns a pressure switch that did not open. Its listed checks are obstructed pressure tubing and a switch stuck closed. Ask the contractor to distinguish that closed-switch condition from code 32, where the switch did not close or reopened.

Related codes

All Carrier furnace codes

Discuss your Carrier furnace code 23 with a contractor

Call (877) 565-3062

One call reaches a contractor registered for your ZIP; ask the fee and the arrival window.

Furnace guides for the wider symptom

Sources

Related equipment, symptoms and component guides

Use each guide with its named equipment and source. A symptom or code alone does not select a replacement part.

What happens when you call about your Carrier furnace code 23

  • Your call routes to an independent local contractor registered for your ZIP code.
  • Ask the fee and the arrival window.
  • The decision to hire stays with you.
Call (877) 565-3062

One call reaches a contractor registered for your ZIP; ask the fee and the arrival window.

Tap to call (877) 565-3062