Bryant furnace code 45: Control Circuitry Lockout
Professional repair
Bryant furnaces share the Carrier control platform — this code table applies to the equivalent Bryant models. Confirm against your unit's panel label.
What does code 45 mean on a Bryant 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.
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)
- Control board internal fault TECH
Parts referenced by this code
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 Bryant 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 Bryant 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 Bryant 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
Bryant 310/311/312 series
Different Bryant 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 · Payne furnace code 45
Verified against Carrier 58STA/58STX Installation & Service Instructions (1106202L), p.37/48
Bryant 310/311/312 series furnaces use the Carrier 58STA/58STX control platform. No separate Bryant 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
Related Bryant furnace codes
These codes use the same status led — short + long flash codes system.