T1800 7-day programmable 3-Heat/2-Cool, controls to, or monitors a 2nd sensor, 3-configurable outputs, Hi/Low outdoor temps of the day, programmable fan, accepts humidity module, smart recovery, Energy-Star rated, meets California residential title-24.

T1900 7-day programmable 3-Heat/2-Cool, controls to, or monitors a 2nd sensor, 3-configurable outputs, Hi/Low outdoor temps of the day, programmable fan, built in humidity module, can average with 1 remote sensor, dual fuel capable, programmable output, reheat capable, smart recovery, dry contact equipped, drain pan alert ready, energy watch, Energy-Star rated, meets California residential title-24.