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Converting from single to dual zone HVAC - Part II

Posted by iostream212 , in HVAC 06 May 2013 · 3295 views

In part 1 I had done the research needed in order to do this project. I also acquired some equipment for the install. Now on to the install!
I hate going up and down into the attic, so the first thing I do is prepare a bucket of tools of everything I can possibly think of needing during the install to minimize the number of trips. One thing I didn’t have was thermostat wire, so off to Lowes! My first clue that something bad was going to happen was right when I walked in. The loud speaker was blaring ‘Special assistance needed in the wire cutting area’. I rushed over there to get in line. The guy in front of me said he had been waiting 5 minutes, and the first clerk who showed up couldn’t do it and had left to get another clerk. Great…  Turns out the guy in front of me also needed 18/5 thermostat wire. The clerk helps him, then on to me. He writes up the identification label tag and hands it to me and starts to walk away without cutting my wire. “Excuse me” I say as I show him my awesome label not attached to anything. “Oh. It’s one of those days,” he laments. Finally I get my wire and I am out of there. I am anxious to beat the sun while I’m tooling around in the attic.
After removing the power to the HVAC system, I grabbed my trusty ladder and began my assent into the dark belly of the beast (AKA the attic). Hello old friend. So we meet again. Hopefully this project will be better than those in the past.
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Here in the attic you can see the two thermostat control boxes for my TR40’s.  The zone controller will mount in this area.
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Here is the zone controller after mounting. It is the unit on the left.
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After mounting the new unit I went to install the HVAC control wire from the HVAC system, but the wire was too short to reach to this location, so I moved it closer. Here it is in the new location and wired to the HVAC system.
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Now its time to hookup the thermostat control boards to the zone controller.  Let me grab that thermostat wire… Wait…something looks wrong here….. LOWES!!!!
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After the setback with the thermostat wire I hopped over to Home Depot and ponied up for the 50ft reel of 18/5 thermostat wire. Here is some time later with the thermostats wired to the board.
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Now to test the install. Board powers up with no issues and all status lights are blinking as expected.
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What’s Next
While in the attic I took a look at the dampers that the HVAC tech said were already installed. I traced the airflow and came to this ominous looking box.
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Since this is not what I was expecting I will have to research a little more to determine how to control these dampers. After that we’ll install the motorized control and the bypass zone.

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