# AC Weirdness / Zone dampers and EcoBee



## SCGrassMan (Dec 17, 2017)

So I have some weirdness with my zone dampers.

I have a two zone system, with two ecobees, and here's whats happened in the past, and what I've experienced.

One zone damper has been replaced. The one that has not been replaced, when it receives voltage, it opens up, and when that voltage is removed, the spring return works correctly, so I am fairly confident that zone damper motor is operational.

What I'm experiencing:

-When the downstairs thermostat is calling, the system fires up, and it opens the zone for downstairs.
-When the upstairs thermostat is calling, sometimes it does, and sometimes it does not.
-Sometimes, the upstairs is calling, and the downstairs is not, and the system is running, but I can tell that the zone damper for the upstairs is still closed, so its running the AC but not blowing out air.
-When I go up in the attic, and watch the zone control panel, when the thermostat should be calling, the light for the zone does not light up. Sometimes, it never does. Sometimes, it does after a few minutes.

What I've done:

-First floor zone damper motor was replaced a couple months back
-System was fully inspected and serviced within the last couple of months
-Disconnected and reconnected the thermostats from the wall
-Power cycled the zone control box
-Switched the breaker off and back on
-Second floor damper is presently unhooked, so the second floor zone damper always stays open, and am basically controlling the temperature upstairs by what temperature I set the downstairs to

Here are what my thoughts on what it could be:

-Zone control box
-Thermostat wiring - loose or damaged wire
-Damaged thermostat
-Physically functional thermostat, but some sort of "smart" feature that is enabled that doesn't "call" right away when changing the temperature

What bugs me, as an IT guy, is that its not consistent. Like if the thermostats NEVER called, or if the zones NEVER opened.

Also, the unit is 10 years old, with a 10 year life expectancy. So, its mechanically sound, but living on borrowed time. I know it needs to be replaced in the next couple of years, but if I can replace the zone control box or something like that and buy more time, great.

Thanks in advance!


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## ionicatoms (Mar 8, 2020)

Swap the ecobees with each other and rule out the thermostat. I would expect a wiring/ground issue, but not anything like an expert. I mostly call out techs for these kind of situations.


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## SCGrassMan (Dec 17, 2017)

ionicatoms said:


> Swap the ecobees with each other and rule out the thermostat. I would expect a wiring/ground issue, but not anything like an expert. I mostly call out techs for these kind of situations.


Yeah that's not a bad idea. But if it's wiring or ground the issue will persist.

I usually do too, but that would be $$$ because they're gonna mark up parts like 200-300%, plus there will be a decent wait in SC in July for an AC tech


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## Thick n Dense (May 7, 2019)

SCGrassMan said:


> ionicatoms said:
> 
> 
> > Swap the ecobees with each other and rule out the thermostat. I would expect a wiring/ground issue, but not anything like an expert. I mostly call out techs for these kind of situations.
> ...


Are these hardwired or using radio signals ?

If radio, id instantly assume an interference issue with wifi walls or other radio devices. It could aslo be a power issue where signal is not strong enough. 
Interference is hard to trouble shoot to actually fix the issues.

Like other poster, swap the units. If same problem occurs than a interfence issue is likely.

After re-reading your post, the obvious potential problem is that the upstairs unit has no control over the downstairs damper. Right? Or are they wired from a central location?

It seems like this bit of logic is failing:
IF(Upstairs unit says on)AND(Downstairs unit Says off) THEN (make sure that downstairs damper is closed)

To me it sounds like this isn't happening at all and the downstairs unit is soley positioned on what the downstairs unit says to be at.

This problem goes both ways.

You said the unit is 10 years old... has the system worked flawlessly up to this point (meaning that the problem just occurred) OR did you just notice it recently ? 
It's important to note if this was a initial setup issue OR a new variable causing the issue.


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## SCGrassMan (Dec 17, 2017)

-Not wireless, wired
-upstairs AC calls for air, but sometimes doesn't open the zone damper


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## ionicatoms (Mar 8, 2020)

I forgot all about this issue. Did you swap the termostats with each other yet?


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