The WHK electric heat strip is designed to be easily installed into the WMA air handler to convert the air handler from a "Cooling Only" unit to an electric furnace. These systems are single phase and use standard 240V wiring and breakers. For use with the WMA 60 only. Please refer to the "System Electrical Requirements" for breaker sizes and wiring. 5 Year - Limited Parts Warranty. Follow the sizing guide for the heat kit best suited for your needs. Must be installed by a licensed contractor. 5 Year Limited Warranty.