Carrier

45

Lockout

Control lockout

IFC parked itself.

5 plates — walk the one on the cabinet

First check

1 Write the live code and watch one cycle

On Carrier 59CU5 read Two-digit IFC (single-stage Comfort — not TP6, not Infinity) before you pull power. Write 45 exactly. Watch one full sequence and note which step dies. Power reset once after the root code is understood. Repeat 45 = board or persistent input.

Expect: W: Single W only. Inducer on → the one pressure switch must close (31 if it does not) → HSI → single-stage valve → flame (34 if no prove) → heat-speed blower.

The rest of the walkthrough is Diagnose.

On the plates

Power reset once after the root code is understood. Repeat 45 = board or persistent input.
Find the root two-digit first.

Plates that use 45

59CU5
Ultra-low NOx · 96% condensing · CA
Diagnose 59CU5 — Sign in
59SC5
Comfort 96 · single-stage · conventional 24V
Diagnose 59SC5 — Sign in
59SP6
Performance 96 · single-stage · variable-speed
IFC parked. Not Rheem 45.
Diagnose 59SP6 — Sign in
59TP6
Performance 96 · two-stage · variable-speed
Diagnose 59TP6 — Sign in
59TP7
Performance 97 · two-stage · variable-speed · InteliSense
Diagnose 59TP7 — Sign in

Same number, other makers

45 on Carrier is not the same code on these plates.