HELPFUL TIP Did you know furnaces can get asthma? Carbon deposits can wreak havoc on efficiency, so have your furnace burners cleaned every 1-2 years. > More Tips   We've got your heating needs covered. Genz-Ryan sells the trusted furnace brands Lennox and Carrier. We offer two-stage variable speed furnaces with efficiency greater than 92%, as well as single and two-stage furnaces with 92% efficiency. One thing to keep in mind: any furnace with greater than 90% efficiency is considered high efficiency and may mean rebates from utility companies. Besides furnaces, Genz-Ryan sells the Venmar product line of Heat Recovery Ventilators, Aprilaire and Honeywell humidifiers and Honeywell zone systems. We also carry a selection of standard furnaces with an 80% efficiency, too. So whatever your needs, we can accommodate.