Automatic Vent Damper

m eannarino

Hi,

Can anyone help me with wiring instructions for bypassing this unit in an emergency situation?

Thanks

Harvey_5

damper

Normal operation the damper is open? Disconnect the power lead and it should go back to the open position. I could use a little more info if you can provide.

Steamhead

Most recent model dampers

have a little switch on the motor housing which does just that. If yours doesn't, I'd disconnect the motor power leads with the damper vane open. DO NOT short out the end switch that keeps the burner from starting if the vane is not fully open.

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m eannarino

Honeywell Automatic Vent Damper Emergency Bypass

Hi,

The device is a Honeywell D80, installed in 1994. After much tinkering it appears that the issue may actually be with the return spring. The "arrow coupler" returns just shy of fully opening the damper, and the furnace won't kick on. If I push the coupler into position (12 o'clock), the furnace lights, runs one heat demand cycle, and then the problem recurs next time around.

First I tried wiring the damper fully open, however it appears that the actuator must reset or the furnace still fails to light for the next heat demand cycle. The D80 does not feature a service switch, and unplugging the unit causes the furnace to shut down.

My local supplier provided me with an M896 motor which is supposed to replace the D80, unfortunately the mounting bracket on the D80 is not the same and is riveted in place through the back plate. The M896 mounts with screws on the sides of the unit.

The tempature was down to 3 degrees around here last night so I had to get this thing running. My interim solution was to leave the D80 in place and plug the modular connector into the M896, which I left sitting on the top of the furnace. This left the M896 "thinking" that it was actuating the damper, and that worked fine, in a pinch.

While observing the operation of the M896 I also noticed that the motor was turning in a clockwise direction! The D80 motor on my damper turns counter clockwise to open it. What's up with that, I don't know? But it would appear that I'm not going to be able to use it.

Anyhow, that got me through the overnight hours and this morning I studyed the wiring diagram on the D80, and conferred with my brother. We agreed that it looked like jumping the blue and the black wires together on the modular plug, would get the unit running. A short piece of 14 guage romex wire plugged right in. It worked! The furnace kicks on as it should, every heat demand cycle, and for now the damper simply remains open all the time. I think I'll replace it with a thermally actuated unit!

Thanks very much to you guys, for trying to help, your quick response is very much appreciated. Take care, and have a great year!

Matt

Andy Morgan_2

Damper

Since you figured out how to bypass the damper, PLEASE somehow rig it so that there is no way that the damper can possibly close. Use tie wire, screws, or whatever! If the damper should close, the boiler would never know and you will be dumping major CO into your home. Better yet, take it out of the flue pipe untill you can get a replacement!

Be Safe!

Andy Morgan

R. Morgan Mechanical, LLC

m eannarino

Honeywell Automatic Vent Damper Emergency Bypass

Hi,

Worry not, the damper is securely wired open and I've got a CO detector plugged in nearby.

Thank you, take care!

kenutter

more help

Well I see this post is old but I am having the same problem. I have had it every winter for the last 8 years. I normally just oil the mechanism up and it works. well I think the return spring is done. The problem is I am not sure what the replacement is. Is it the D896?

bill_105

just did one today

Fields has a universal one with a multiple choice wiring harness. Just gravy

kenutter

Fields damper

5" Automatic GVD Vent Damper - GVD-5PL. Is this the model you are referring to? I see it says power open and power close. My existing unit is only power close and spring load open (which is not working right now) but will my boiler that only has a 4 prong plug do the power open?

Tim McElwain

Yes it will

work or yours which is a Honeywell can be replaced by a Honeywell D896 version.

kenutter

thanks

Thank You