During my twenty point heating inspection, I started with the thermostat. Giving a call for heating, and going to furnace to start maintenance. Temp rise of 40-70 needed, I got a temp rise of 43. House heats up to designated temperature. I checked out blower motor of any dirt or debris and it’s clean. Replaced air filter for new air filter. Owner had extra one, so just used his. Hot surface igniter not cracked or having white spots. Flame sensor still working good, no need to be cleaned. Ducting done correctly, and all runs intact. Inducer motor is working efficiently.