Carrier Heat Pump Error Code 43: How to Fix It

Q: What causes Carrier heat pump error code 43?

Error code 43 is caused by low refrigerant pressure, typically due to refrigerant leaks, dirty coils restricting airflow, faulty expansion valves, or a failing low-pressure switch protecting the system.

Q: Can I fix Carrier error code 43 myself?

You can perform basic maintenance like changing air filters and cleaning coils, but refrigerant system repairs require professional service. Only EPA-certified technicians can legally handle refrigerant and repair sealed system components.

Q: Is it safe to run my heat pump with error code 43?

No, never run the heat pump with error code 43. This safety lockout prevents compressor damage from low refrigerant pressure. Continued operation could cause expensive compressor failure requiring full system replacement.

Q: How much does it cost to fix Carrier heat pump error code 43?

Repair costs vary from $200-$800 for minor refrigerant leaks and recharging, up to $1,500-$3,000 for major component replacement like the compressor or extensive leak repairs, depending on the underlying cause.

Q: How can I prevent Carrier heat pump error code 43?

Prevent error 43 by changing air filters regularly, scheduling annual professional maintenance, keeping coils clean, maintaining proper clearance around outdoor units, and addressing any performance issues promptly before they damage the refrigerant system.

Abstract

Error code 43 on your Carrier heat pump indicates a low-pressure switch lockout, which means the refrigerant pressure has dropped below safe operating levels. This is a critical error that protects your system from damage but requires immediate attention to prevent compressor failure.