the gas valve would be opened resulting in shutdown of the furnace as well as the reclaiming apparatus if gear motor 16 or the reclaim blowers 34 fail the resulting high temperatures in the ordinarily cold exhaust duct 10 will trip a thermal protection switch located in the duct and set to trip at 200 u00b0 f shutting off electrical power to the furnace gas valve and the reciprocating energy reclaiming apparatus the thermal protection switch 54 is of the automatic reset at 160 u00b0 f type as a safety backup if the thermal protection switch fails there is a thermal switch in exhaust motor 23 that will also trip and shut off exhaust motor 23 resulting in shut off of both the gas valve and the reclaiming apparatus should any electrical component have a fault an electrical fuse built into the reciprocating energy reclaiming apparatus would blow shutting off the gas valve and apparatus should any of the three fans or the reciprocating gear motor fail to function properly safety controls will automatically shut off the main gas valve to the gas furnace should the exhaust fan 22 fail to function a pressure switch on the discharge of the fan would lose pressure resulting in the main gas valve circuit being interrupted if the reciprocating gear motor 16 fails to function there would be no heat exchange resulting in the exhaust hot air passing straight through the mesh heating up.