Flu Damper \"proved\"

Art Pittaway

Is the damper required to have a "Proving switch" in spec's that you see? I assume the switch is in series with the gas valve to prevent firing before it is open.

Here's the hard question, is the switch part of the actuator or actually making on the position of the damper? If the linkage comes loose, could it fire with a closed damper.

What have you seen? Tim?

Unknown

End switches

on dampers are required to be two switches in series and they are actuated by the damper movement. The two switches is a safety in the event one sticks, odds on both sticking pretty slim.

Honeywell dampers are powered open and spring closed when a relay in the damper removes power from the motor.

Effikal and Johnson and most others are "power to open" "power to close". They also have two switches as end switches to bring in power to the gas valve circuit.

Safety with these has not been an issue unless someone starts getting cute and jury rigs them. Most issues with them has been a fairly high rate of failure. Techs get frustrated and jam them open and jump out the safety cicuit to keep them running.

Don_4

Dampers

Fortunately Tim not all techs bypass the safety switch. I personally have by-passed numerous Flair dampers. I simply remove the power wire at the head which drives the damper closed. The spring then holds the damper open and I install a screw to keep it that way. Should the screw fall (rust) out the safety circuit is still intact and the furnace will not fire (damper closed). When I run across a particular damper that will not allow this the damper gets replaced with an appropriate piece of venting.

Unknown

Don are you leaving

dampers removed or secured open on a permanent basis?

Don_4

dampers

Secured open but with end switch intact so that if damper fails and falls closed furnace will not fire.