I build my house a year ago. The builder installed Janitor furnace 80% eff. When I try to keep the setting at 71 degree or above(even at 77 degree), the temperature in the house always at 70. if I keep the setting at 70 degree, the temperature in the house in 68 degree. Or if keep the setting at 69 degree, it will be 66 degree. At first I thought there is problem with thermostat. So I replaced it, but did not fixed the problem. Anyway, all Janitor products are sucks and junks.