damper

if anyone could give some ideas that would be great. I have a hot water boiler system that sometimes does not kick on when thermostat calls for heat. It is a 2 zone boiler system with two thermostats. The damper is in the always open position. When not running the water pressure is between...

I am looking for a solution from all you wizards out there. I have a home built in the mid 1990's. The bathroom exhaust fans vent to the roof without a damper or screen. I would like to find a "topper" to retrofit on top of the roof with a screen and efficient damper. It needs to be installed...