topic Re: Can I combine RH and RC and use RC/C to charge while RH/W to control my furnace? Dual transforme in Nest Thermostats

Can I combine RH and RC and use RC/C to charge while RH/W to control my furnace? Dual transformers..

yyuus — Mon, 04 Jul 2022 02:37:52 GMT

Hi,

Thanks for everyone and long story short

Dual transformer system, purchased a nest thermo (only one R, instead of RC and RH separately)
from my AC unit I have: RC + C + G(fan) + Y
from my furnace unit I have: RH + W
I am just using the nest thermostat to control the furnace only
previously, the honeywell thermo connected RC+RH + C + W. I think the thermo was using RC+C to charge, while RH+W to control the furnace
However, given google nest only has one R, can I combine RC and RH and both connect to R? In that way, I use the RC/C to charge while RH /W to get the job done? I think it shall work but just wondering if any concern?

Thank you!

Re: Can I combine RH and RC and use RC/C to charge while RH/W to control my furnace? Dual transforme

yyuus — Mon, 04 Jul 2022 13:04:20 GMT

I guess the issue might be circulation? The voltage of my furnace transformer and AC transformer though are supposed to be 24v but anyway they are going to be slightly different...in that case, electricity will travel from higher vol system to the lower vol system and circulate within the transformers -- causing attrition and might damage the transformers?

Re: Can I combine RH and RC and use RC/C to charge while RH/W to control my furnace? Dual transforme

MelbaDT — Sat, 09 Jul 2022 08:03:43 GMT

Hey yyuus,

Thanks for reaching out and for the detailed description of your concern.

I'm afraid we can't provide a definite answer to your questions as professional installation is recommended for your system since the wiring and setup can be complicated. Please contact a local pro for better assistance.

Best,

Melba

Re: Can I combine RH and RC and use RC/C to charge while RH/W to control my furnace? Dual transforme

MelbaDT — Wed, 13 Jul 2022 03:23:28 GMT

Hey there,

Checking back in should you have further questions here. Let us know by replying to this thread.

Best,

Melba

Re: Can I combine RH and RC and use RC/C to charge while RH/W to control my furnace? Dual transforme

MelbaDT — Thu, 14 Jul 2022 03:31:27 GMT

Hi,

We haven't heard from you in a while so we'll be locking this thread if there is no update within the day. If you have any new issues, updates or just a discussion topic, feel free to start a new thread in the Community.

Best,

Melba