Venter Damper Rewire?

mroberts5

I have my system on a Vaporstat. I'm trying to run it from 8-10 oz down to 2-4, but because my vent damper takes so long to open, I keep hitting 0. I've tried lowering the differential to the minimum, and this sort of works, but now the cutout is 10 oz and cut in is 8. The damper is just constantly opening and closing, which will surely lower it's life.

I want to rewire the controls so the vaportstat is after the damper...which will keep the damper open as the vaportstat cycles. I design control systems for a living so I'm very comfortable with the work but wanted to see if anyone here thought I'd be making a mistake leaving the damper open between pressure cycles.

Thanks.
Matt

Jamie Hall

Well now... if you are in controls, you know that all the safeties -- including both the the vent damper end switch and the vapourstat -- have to be satisfied before the start sequence can begin. Placing the vent damper before the vapourstat shouldn't make any difference.

You'll have to figure out a way to wire it so the vent damper is commanded to open when the thermostat is calling. Then its end switch and the rest of the safeties in series in the usual way.

gerry gill

i rewired my damper so it opens on a call for heat and doesn't close until the call is over. Less wear and tear on the damper motor and faster response.

mroberts5

Glad to hear you had the same idea. For anyone interested here is what I did.

ethicalpaul

I’m interested, thanks!

coelcanth

gerry gill said:

i rewired my damper so it opens on a call for heat and doesn't close until the call is over. Less wear and tear on the damper motor and faster response.

i mean, isn't this how they're normally wired ?? my damper opens before the gas valve fires and then it's the last thing to close at the end of the cycle

mroberts5

coelcanth said:

gerry gill said:

i rewired my damper so it opens on a call for heat and doesn't close until the call is over. Less wear and tear on the damper motor and faster response.

i mean, isn't this how they're normally wired ?? my damper opens before the gas valve fires and then it's the last thing to close at the end of the cycle

Not exactly. The pressure switch is BEFORE the vent controller, so if you happen to be cycling on pressure, the damper will close/open each time you hit pressure. With the modification shown the pressure switch is AFTER the damper, so it will stay open until the thermostat is satisfied.