Lennox 88K09 Sequencer

The Lennox 88K09 Sequencer is an electrical control part used to manage the staged activation of heating elements such as electric furnace coils. It detects the temperature changes and energizes or de-energizes individual heating stages in sequence to match heat output with demand in HVAC systems. This is installed inside residential and light commercial air handlers, where it interfaces with the thermostat and control board. It regulates heat delivery and ensures balanced electrical load distribution for consistent heating performance.