Lennox Equipment Interface Module. ATTENTION: The Lennox icomfort Wi-Fi® thermostat is required for use with this Equipment Interface Module. This Equipment Interface Module will work with most 24VAC furnaces, air conditioners, air handlers and heat pumps (up to 3-stages of heat and 2-stages of cooling). EXCEPT: it will NOT work with any brand of communicating HVAC equipment other than Lennox®. If you are unsure you can apply this interface with your equipment, please contact us BEFORE you order.