Carrier 59SC2B Furnace Error Codes

Single Stage Gas Furnace | Control Board: HK42FZ034-type furnace control board

Not your model? View all Carrier models →

Disclaimer
This information is for reference purposes only and does not guarantee accuracy or completeness. Always consult your owner's manual and a licensed HVAC technician for diagnosis and repair. Any actions taken based on this information are at your own risk.

All Error Codes

Code Name Severity DIY?
Continuous OFF No Power / Control Failure High ✓ Yes →
Continuous ON Normal Operation - No Call for Heat Info — →
Rapid Flashing Reversed Line Voltage Polarity High ✗ Call a pro →
11 No Previous Code Info — →
12 Blower On After Power Up Info — →
13 Limit Circuit Lockout High ✓ Yes →
14 Ignition Lockout High ✓ Yes →
21 Gas Heating Lockout High ✗ Call a pro →
22 Abnormal Flame-Proving Signal High ✗ Call a pro →
23 Pressure Switch Did Not Open High ✗ Call a pro →
24 Secondary Voltage Fuse Is Open High ✗ Call a pro →
31 Pressure Switch Did Not Close or Reopened High ✓ Yes →
33 Limit Circuit Fault High ✓ Yes →
34 Ignition Proving Failure High ✓ Yes →
45 Control Circuitry Lockout High ✗ Call a pro →

How to Read the Error Code

Carrier furnaces use a two-digit LED blink code on the control board. An amber LED flashes a short-then-long pattern: count the short flashes (first digit) then the long flashes (second digit). For example, three short flashes followed by three long flashes means code 33. The board stores recent fault codes for retrieval.

About This Model

The Carrier 59SC2B is a single stage gas furnace using the HK42FZ034-type furnace control board control board.