Installing a Nest Thermostat for heating with an ARGO 6P Zone controller

gjlian

Replacing a Honeywell 2 wire thermostat with a Nest "Smart" thermostat is causing chattering of the relays. I've been reading forums and called both Nest as well as ARGO for advice. Nest simply told me to run a 3rd wire to the common terminal on the Nest which is a major hassle in an old house. I've also read about installing a local 24 volt power source near the Nest thermostat which is clunky in my opinion. Any thoughts or ideas are welcome. Thanks

NY_Rob

I had to pull new t-stat cables when I when from old 2-wire stats to modern programmable stats. It was a pain pulling new wires, but better than running a wall-wart transformer to each t-stat for power.

You can temporarily run any of the new stats off local 24vac transformers till you can pull new cables back to your boiler.


Ironically... when I upgraded to a mod-con boiler, I went back to simple 2-wire t-stats again

Jamie Hall

As @NY_Rob says -- take your pick. Or pick one of the battery powered, programmable Honeywells, if you don't need internet connectivity.

hot_rod

Or get an Add a Wire kit. I think Ecobee includes that kit with some of there stats.


https://smartthermostatguide.com/c-wire-venstar-add-a-wire-adapter-review/

NY_Rob

@hot rod ....

I looked it to that "add a wire kit" and stopped where it stated "Cannot be used as "R" power or "C" common wire. "

If you look at the Q&A on Amazon it states:
"Unfortunately this cannot be used to turn 2 wires into 3. It is specifically designed for 4-5 or 5-6 situations."

gjlian

Thanks for all the posts. I'm planning on installing an ARGO IR 882 (isolation relay) alongside the ARGO 6P this weekend. I'm told this will solve the problem. Total cost - $65 for IR 882 + $20 for 120/24 v transformer needed to power the relay. I will post the results on Monday in case anyone is interested.

NY_Rob

^ Will the ARGO IR 882 supply power needed for your Nest over the existing 2 wires? I would contact them to be sure.

hot_rod

NY_Rob said:

@hot rod ....

I looked it to that "add a wire kit" and stopped where it stated "Cannot be used as "R" power or "C" common wire. "

If you look at the Q&A on Amazon it states:
"Unfortunately this cannot be used to turn 2 wires into 3. It is specifically designed for 4-5 or 5-6 situations."

Good to know, someone suggested there is a kit that can add a common. Maybe wi fi? Is that what Ecobee uses?

gjlian

I did speak to ARGO and yes they said it should work. I have a back up plan in case it doesn't but I'm cautiously optimistic at this point.

NY_Rob

I hope you will post back with results.....

gjlian

The ARGO isolation relay worked like a charm ! No more chatter

tjmagalhaes

Gjlian, I have the same issue. Can you post a photo of the final wiring at the argo boards?