should the power vent be always running?


Old 07-05-18, 07:19 AM
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should the power vent be always running?

we're in the midst of a heat wave here in New England, so the boiler is certainly not calling for heat. the boiler also heats water so I guess it might need to come on occasionally but it seems like just the vent part is constantly on. is that normal??

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Last edited by PJmax; 07-10-18 at 02:03 AM. Reason: reoriented pictures
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Old 07-05-18, 07:28 AM
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If the unit is running, then the fan should be running, even if it is just heating water, obviously. The fan should be set to run for a least a while even after it shuts down to make sure its pulling any leftover gasses.
As far as running constantly, I would not think so, could be a bad or just dirty relay?
Old 07-05-18, 10:27 AM
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It's not normal.
Old 07-07-18, 03:50 AM
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Power vent

That boiler is not power vented so there is no fan. It is an atmospheric vented boiler. What you are referring to in your pictures is a vent damper, closed when boiler is not running, open when boiler is on. Unless it is locked open on manual with the small switch on the side opposite from where the molex plug us connected. If the motor is constantly turning the damper, then it needs to be replaced. You can replace just the motor without having to disassemble the entire flue pipe by removing the two screws that hold the motor to the bracket.
Old 07-09-18, 05:03 AM
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Hi, something in the boiler circuit is causing that motor to be powered, unless it is turned on manually by the switch on the side, changing the motor probably won’t help, you need to determine what is calling that vent to open, trace that piece of flex and see where it terminates and remove one of the conductors and see if the motor shuts off, post a pic of the wiring dia. If you have one.
Old 07-10-18, 12:53 AM
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Think of these vents have an open or closed state, not on or off. When 24 volts is applied, motor moves damper 90 degrees and activates switch that removes power from motor. A second switch then opens or closes to signal that state to outside world.

Next time 24 volts is applied motor moves damper 90 degrees to next state.

When vent is not moving, either open or closed, motor is not powered.

Most electric vents have a manual third switch on the motor board to keep it always open.

Maybe Geochurchi's switch is keeping it open.

Last edited by doughess; 07-10-18 at 01:14 AM.

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