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Lennox Harmony II zone control
Devan
Member Posts: 138
On a recent project, replaced hot water heting system , replaced honeywell round heat/cool thermostats and upgraded thermostats to electronic heat/cool stats.
Testing the system found the existing Lennox Harmony II zone control and Lennox CB21 air handler not working in cool mode.
Going thru the controls I see previous a/c contractor only used R & Y terminals in Harmony control.
Not sure if I have to add a relay between my new stats?? Any help appreciated.
Thanks
Testing the system found the existing Lennox Harmony II zone control and Lennox CB21 air handler not working in cool mode.
Going thru the controls I see previous a/c contractor only used R & Y terminals in Harmony control.
Not sure if I have to add a relay between my new stats?? Any help appreciated.
Thanks
0
Comments
-
Schematic
How are the wires connected at the A/H zone board and t-stat? How were they wired before? Did you shut down the A/H power before changing the stat? Maybe you shorted a wire and (hopefully) popped a fuse.0 -
LED's on
so zone control board seems to be powered up.
From thermostat into control board only R&Y were used. Since I was not doing any additional AC work, I really did not look into the board until now. Old thermostats only use R&Y as well, but I did connect R,Y and G to the new stat., but at the Harmony board G was not used.0
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