Chimney Flue Motorized Damper

[mattd860]

My wood boiler (Harman SF-160) heats the oil boiler in a series circuit. When my wood boiler reaches 150 degrees the electronic controls turn off the oil burner relay, preventing the oil burner from starting. This ensures that my wood boiler is the sole source of heat and hot water. I would like to install a motorized damper in the chimney flue coming from the oil burner to prevent heat from escaping. I was thinking about getting a normally open damper that will close when the oil burner is turned off.

Are there codes or other reasons why I shouldn't do this? Are there specific dampers made for this type of purpose? Right now I only see simple HVAC dampers that seem to be light duty only. I'm afraid one of those dampers might not be able to withstand the heat from the oil burner. If the damper were ever to get "stuck closed".... I would probably never know

 

[mikefrommaine]

http://www.fieldcontrols.com/ovd.php

Field controls makes what you want. Closed unless the oil burner is running.

 

[thecontrolguy]

My wood boiler (Harman SF-160) heats the oil boiler in a series circuit. When my wood boiler reaches 150 degrees the electronic controls turn off the oil burner relay, preventing the oil burner from starting. This ensures that my wood boiler is the sole source of heat and hot water. I would like to install a motorized damper in the chimney flue coming from the oil burner to prevent heat from escaping. I was thinking about getting a normally open damper that will close when the oil burner is turned off.

Are there codes or other reasons why I shouldn't do this? Are there specific dampers made for this type of purpose? Right now I only see simple HVAC dampers that seem to be light duty only. I'm afraid one of those dampers might not be able to withstand the heat from the oil burner. If the damper were ever to get "stuck closed".... I would probably never know

There are codes here in Canada, however, just for your safety ensure that the flue damper has an interlock contact that is OPEN when the damper is closed. Wire the boiler enable from the wall thermostat, or aquastat (or whatever tells your gas boiler to start) through the contacts on the damper. Then, you enable the damper actuator of the flue damper, which then physically opens, making its normally open contacts that then energize the boiler. This way the boiler can NEVER be energized when the flue damper is closed, or not FULLY open. Carbon monoxide is not your friend, just be safe. Good luck.

 

[mattd860]

The damper mentioned above my mikefrommaine is exactly what I'm looking for. The oil burner will not be able to fire until the damper is fully open. Also - the damper will stay open for 3 minutes after the burner has stopped fireing allowing remaining carbon monoxide to escape.

My wood boiler completely cuts power to the oil burner once the wood boiler heats up to 150 degrees so essentially, both the burner and damper will always remain closed when I'm burning wood. Apparently, during times when I'm burning only oil, this damper will cut my fuel consumption by 5-10%