HVAC●FAULTS
PAYNE DIAGNOSTIC REFERENCE STATUS LED — SHORT + LONG FLASH CODES DOC PAYNE-45

Payne furnace code 45: Control Circuitry Lockout

YOUR LIGHT: 4 SHORT + 5 LONG FLASHES — MATCH IT ABOVE

Professional repair

Payne furnaces share the Carrier control platform — this code table applies to the equivalent Payne models. Confirm against your unit's panel label.

What does code 45 mean on a Payne furnace? Auto-resets after 1 hour. Official causes: gas-valve relay stuck open, flame-sense circuit failure, or a software check error. Reset power to clear; replace the control if it repeats.

Before you touch anything: the six signs that mean stop troubleshooting and call a pro →

GOOD NEWS: THE FIRST CHECKS ARE FREE AND TAKE MINUTES.

Try these first — in this order

One power-cycle (30 s) is the official reset.

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If code 45 returns, the board gets replaced. DIY part cost: $120–250 — a pro visit for this class of fault typically runs $150–350.

What causes it (in order of likelihood)

  1. Control board internal fault TECH

Parts referenced by this code

HK42FZ034 — Furnace Control Board
$120–250 · also sold as HK42FZ013

Always match parts against your model's parts list — part numbers vary within a series.

Questions about this code

What does code 45 mean on a Payne furnace?

Auto-resets after 1 hour. Official causes: gas-valve relay stuck open, flame-sense circuit failure, or a software check error. Reset power to clear; replace the control if it repeats.

How do I fix Payne furnace code 45?

Causes include a stuck gas-valve relay, a flame-sense circuit failure, or a software check error. Don't keep resetting it; if it returns, a technician should diagnose the control.

How much does it cost to fix Payne furnace code 45?

Cost depends on whether the lockout recurs. If it does, the manual points to replacing the control, and parts availability and labor will shape the price.

Applies to

Payne PG8M series

Different Payne generations use different code maps. If your series isn't listed, don't assume this meaning — check your blower-door label.

Same control platform, same code: Carrier furnace code 45 · Bryant furnace code 45

Verified against Carrier 58STA/58STX Installation & Service Instructions (1106202L), p.37/48

Payne PG8M series furnaces use the Carrier 58STA/58STX control platform. No separate Payne service document is cited — confirm the code map against your unit's panel label.

Last verified 2026-07-06 · page updated 2026-10-03 · how we verify

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These codes use the same status led — short + long flash codes system.

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