No heat Duluth. Found 14 year old furnace working on arrival. Flame sensor does look worn which can cause flame to kick off. Inducer motor is running at higher amps than rated for and can soon burn out. Blower wheel is a little dirty and needs to be cleaned before it start causing stress on system. Capacitor is very weak and needs to be replaced. System has no back up water safety switch to prevent water damage to furnace. System would also benefit from having Uv light system installed to kill harmful bacteria and viruses in the air. Evap coil is rusted and corroded which is a sign the copper is getting eaten away and can cause a leak.