Timeline for C wire possible for Nest thermostat?
Current License: CC BY-SA 4.0
6 events
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| Mar 15, 2021 at 22:40 | comment | added | tannranger | We only have 1 thermostat hooked up, pulling max 200mA according to the display. If we ever hook up a second that pulls from the C wire that would definitely be something worth checking though, agreed. | |
| Mar 15, 2021 at 21:45 | comment | added | jay613 | Hmm. I guess one thing you might want to worry about is the combined current of one pump and 6 thermostats might be more than designed for the current path back from pin 1 to the transformer. Unlikely ... you would think a pump will draw orders of magnitude more than a thermostat. There's a tech support number on the last page of the manual ... call it! | |
| Mar 15, 2021 at 21:38 | comment | added | jay613 | The information on p16 confirms what I guessed from the sticker on the cover. A further guess is from the green color of the wires on pin 1. Not exactly scientific I admit. Hence you should confirm it with a continuity tester. My guess is that pin 1 is always connected to C and pin 2 is energized when called for. It could be the other way around, that would be an odd use of wire colors but sure. It could also be that pins 1 and 2 are both disconnected from anything when heat is not called for but that would be a bizarrely unnecessary way to complicate the control board. | |
| Mar 15, 2021 at 21:29 | comment | added | tannranger | Wow! Did exactly as you said after confirming continuity from C terminal to pin 1 of the first pump terminal. After connecting the various loose wires (and again confirming continuity from C terminal to the twisted yellow wire bunch), looks like I'm getting healthy current to my Nest! photos.app.goo.gl/gvzbKsggB7mbJSj77 | |
| Mar 15, 2021 at 20:50 | comment | added | tannranger | A concern though, according to the manual, those terminals only receive 24V when a thermostat is calling for heat, see 16/20: argocontrols.com/sites/default/files/AZ4CP%20AZ6CP%20IOM.pdf | |
| Mar 15, 2021 at 20:28 | history | answered | jay613 | CC BY-SA 4.0 |