HVAC Code Lookup

Payne Furnace: 4 Flashes

A Payne furnace LED pattern starting with 4 flashes matches 7 documented codes: 42, 43, 45, 45.1, 45.2, 45.3, 46.1. Watch the full pattern (short vs. long flashes) to tell them apart — all 7 are explained below.

Code 42: Inducer RPM fault

WarningShown as: 4 short flashes, 2 long flashes; minor codes 42.1, 42.2 and 42.3

Inducer RPM fault. 42.1 means no RPM feedback at start-up or before ignition proved; 42.2 means the RPM signal was lost for 5 seconds after ignition proved; 42.3 means the inducer is exceeding its model-specific RPM limit.

Manual wording: “42.1 NO RPM FEEDBACK - at start-up or before ignition proved. 42.2 NO RPM FEEDBACK - after ignition proved, signal was lost for 5 seconds. 42.3 EXCEEDING INDUCER RPM LIMIT”

Documented for: PG80MSU

Likely causes, most common first

  1. Improper vent sizing
  2. Restricted combustion air supply
  3. Failed inducer motor
  4. Improper or loose motor wiring or a bad connection

What you can safely check yourself

  • Check the outdoor intake and exhaust pipes for snow, ice, leaves, or a nest blocking them

When to call a technician

The inducer motor and its wiring must be tested by a technician. A furnace that cannot run its inducer cannot vent combustion gases safely.

A Payne furnace throwing this code repeatedly has a reason — clearing the code without fixing the cause just hides it.

Source

Full page for Payne code 42

Code 43: Low-heat pressure switch open while the high-heat pressure switch is closed - a contradictory pressure-switch state on a two-stage furnace

WarningShown as: 4 short flashes, 3 long flashes

Low-heat pressure switch open while the high-heat pressure switch is closed - a contradictory pressure-switch state on a two-stage furnace.

Manual wording: “43 LOW-HEAT PRESSURE SWITCH OPEN WHILE HIGH-HEAT PRESSURE SWITCH IS CLOSED”

Documented for: PG96VTA

Likely causes, most common first

  1. Low-heat pressure switch stuck open
  2. Disconnected or obstructed pressure tube
  3. Miswired pressure switches
  4. Low inlet gas pressure (if LGPS used)
  5. Plugged condensate drain
  6. Water in the vent piping from a sagging pipe

What you can safely check yourself

  • Check the condensate drain line and trap for a clog or standing water
  • Check outdoor vent terminations for blockage

When to call a technician

Pressure switch wiring and vent piping slope are technician diagnostics. Never jumper a pressure switch.

A Payne furnace throwing this code repeatedly has a reason — clearing the code without fixing the cause just hides it.

Source

Full page for Payne code 43

Code 45: Control circuitry lockout

Soft lockoutShown as: 4 short flashes, 5 long flashes

Control circuitry lockout. The board detected an internal failure and locks out, auto-resetting after 1 hour.

Manual wording: “45 CONTROL CIRCUITRY LOCKOUT Auto-reset after 1 hour lockout due to: - Flame circuit failure. - Gas valve relay stuck open. - Software check error.”

Documented for: PG92ESA, PG95ESA, PG96VTA

Likely causes, most common first

  1. Flame circuit failure
  2. Gas valve relay stuck open
  3. Software check error

What you can safely check yourself

  • Turn the furnace off at the service switch for a minute and back on once - the manual says resetting power clears the lockout

When to call a technician

Payne's own instruction is to replace the control if the code repeats after a power reset. That is a technician job.

A Payne furnace throwing this code repeatedly has a reason — clearing the code without fixing the cause just hides it.

Sources

Full page for Payne code 45

Code 45.1: Control failure - flame circuit fault, memory mismatch, or sequence error on the control board

Soft lockoutShown as: Major code 45 on the LED (4 short, 5 long); 45.1 on the display

Control failure - flame circuit fault, memory mismatch, or sequence error on the control board.

Manual wording: “45.1 CONTROL FAILURE - flame circuit fault, memory mismatch or sequence error.”

Documented for: PG80MSU

Likely causes, most common first

  1. Internal control board failure

What you can safely check yourself

  • Turn the furnace off at the service switch for a minute and back on once - the label says to cycle power

When to call a technician

The label says that if code 45 repeats after cycling power, the control must be replaced.

A Payne furnace throwing this code repeatedly has a reason — clearing the code without fixing the cause just hides it.

Source

Full page for Payne code 45.1

Code 45.2: Control failure - the gas valve relay will not close

Safety faultShown as: Major code 45 on the LED (4 short, 5 long); 45.2 on the display

Control failure - the gas valve relay will not close.

Manual wording: “45.2 CONTROL FAILURE - gas valve relay will not close.”

Documented for: PG80MSU

Likely causes, most common first

  1. Failed gas valve relay on the control board

What you can safely check yourself

  • Turn the furnace off at the service switch and leave it off until a technician arrives

When to call a technician

A gas valve relay that will not close means the board cannot reliably shut off gas. Shut the furnace down and call a technician; the fix is a new control board.

A Payne furnace throwing this code repeatedly has a reason — clearing the code without fixing the cause just hides it.

Source

Full page for Payne code 45.2

Code 45.3: Control failure - EEPROM memory issue on the control board

Soft lockoutShown as: Major code 45 on the LED (4 short, 5 long); 45.3 on the display

Control failure - EEPROM memory issue on the control board.

Manual wording: “45.3 CONTROL FAILURE - EEPROM memory issue.”

Documented for: PG80MSU

Likely causes, most common first

  1. Corrupted or failed memory on the control board

What you can safely check yourself

  • Turn the furnace off at the service switch for a minute and back on once

When to call a technician

If the code repeats after cycling power, the control board has to be replaced by a technician.

A Payne furnace throwing this code repeatedly has a reason — clearing the code without fixing the cause just hides it.

Source

Full page for Payne code 45.3

Code 46.1: Momentary loss of power

StatusShown as: 4 short flashes, 6 long flashes; 46.1 on the display

Momentary loss of power. Heating stops and restarts on its own once the power fluctuation is resolved.

Manual wording: “46.1 MOMENTARY LOSS of power - Heating operation will stop and will restart once the power fluctuation is resolved.”

Documented for: PG80MSU

Likely causes, most common first

  1. Brownout or brief power interruption to the furnace

What you can safely check yourself

  • Nothing to fix if you had a power blip
  • If it repeats without outages, check that the breaker is fully on and the furnace service switch is not loose

When to call a technician

Frequent 46.1 codes with no utility outages usually mean a loose 115 V connection or a failing door switch - have a technician check it.

A Payne furnace throwing this code repeatedly has a reason — clearing the code without fixing the cause just hides it.

Source

Full page for Payne code 46.1

Other Payne codes