Damper actuator
Damper construction for a gas fired combustion apparatus
Damper construction for a gas fired combustion apparatus
Damper construction for a gas fired combustion apparatus
Damper control apparatus
Damper control device
Damper control mechanism
Damper latch
Device for controlling heating efficiency of water heater
Device for draft control
Device for use with flue dampers
Digital modulation for a gas-fired heater
Draft control arrangement
Draft control arrangement
Draft control arrangement for combustion apparatus
Draft control arrangement for combustion apparatus
Draft control arrangement for combustion apparatus
Draft control arrangement for venting of combustion apparatus
Dual deadband control system
Dual duct variable volume air conditioning system