Vent Damper Wont Stop cycling until I hit it.

Old 02-27-08, 07:42 AM
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Vent Damper Wont Stop cycling until I hit it.

Ive got a 20 year oldWeil-McLain hot water boiler that works great.
But over the past two years it wont fire up (about once a week), until I go down and bang on the duct with the vent damper in it.
The Vent damper is continuosly turning until I bang on it. Then it stops and the furnace fires up.
I would say the frequency has doubled from once a week to 3 times a week. The Vent damper is a johnson Mizer #M15AC.
Any suggestions?
Old 02-27-08, 02:47 PM
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Originally Posted by crownm View Post
Any suggestions?
Replace it. It don't owe you a dime, and it's a safety issue.
Old 02-27-08, 02:50 PM
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Vent Damper

Most vent dampers have a switch in them which closes when the damper comes to it's open position, stops the damper motor, & allows the burner to fire. Sounds like the switch has gone bad. I'm not at all familiar with that particular damper thus I can't tell you if the switch is replaceable or not.

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