The Affinity™ YP9C modulating gas-fired furnace features a 97.5 to 98 percent AFUE rating, as well as a modulating gas valve, inducer, and circulating blower for modulating operation from 35 to 100 percent input in 100 increments with a nearly constant temperature increase.

The unit can be installed with diagnostics that transmit fault codes, thanks to the Affinity touch screen communicating control system, which uses a four-wire connection bus. The control also provides easy adjustment of the blower and continuous fan operation and humidification and/or dehumidification for homeowners. The furnace can also be incorporated into a hybrid comfort system by pairing it with a York heat pump.