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
Electrically controlled programmable digital thermostat and meth
Electronic drain system
Electronic temperature control system for thermostatic control
Electronically based control valve with feedback to a...
Electronically-controlled register vent for zone heating and...
Electronically-controlled register vent for zone heating and...
Energy control system providing selective control of remote zone