dF CodeUpdated 14 days ago

The “dF” code means the system is in defrost mode.

This article is for the following systems: 

• Diamante Essenza High-Wall (WYT-17)
• Diamante Essenza High-Wall (WYT-20U)
• Diamante Pro High-Wall (WYT-20S)
• Quantum Ultra High-Wall (WYT-24)
• Quantum Hyperformance High-Wall (WYT-25)
• Quantum Fresh High-Wall (WYT-FA)
• Quantum Ultra 8-Way Ceiling Cassette (CYT-24)
• Quantum Ultra Ducted Ceiling Concealed (RYT-24)
• Quantum Ultra Universal Floor-Ceiling Flex (UYT-24)

Frost can build up on the outdoor coil in cold or humid conditions. When this happens, the system temporarily switches into defrost to clear the frost. During this time, the indoor heating may pause briefly, and the outdoor unit may make different sounds than usual.

This is normal operation in cold weather. Once the defrost cycle is complete, the system will automatically return to heating.