Nest Thermostat installation on multi-zone Taco SR506-ESP

[Shamrocks24]

 HI!

Could use some assistance. Installing these is not always as easy as expected. I have a multi-zone Taco SR506-ESP switching relay. I have 5 zones, but only need to control 3 zone with new Nest thermostats.

I do NOT have the required C wire at each location and can't run new wires to the units. I have a couple of questions:

1. Will I need a separate Google Nest power connectors for each zone?
2. Can I connect all 3 "C" wires into the 1 "C" block? I don't see 5 separate "C" blocks on the relay.C block close up

Your experienced guidance is greatly appreciated!

Thanks!

[EmersonB]

Hi Shamrocks24,

Thanks for reaching out here in the Community. Generally speaking, Nest thermostats are compatible with zoned system panels. But some zone relay panels don't provide the Nest thermostat with enough power to charge its internal battery. In this case, the Nest thermostat needs the Nest Power Connector or a common or “C” wire connected to provide power. You can contact a Nest Pro in your area to see if the power connector or a common wire is needed and to estimate the cost of installing one in your home in order for your system to become compatible with a Nest thermostat. You might need the Nest Power Connector for each zone and a separate C wire for each relay. It still depends on your system, that’s why we highly recommend you to contact Nest Pro to help you out about that installation.

Regards,

Emerson

[Shamrocks24]

Thank you Emerson!

Now I just need to determine if the Taco SR506-ESP switching relay has a "C" block fo each zone.

[Jenelyn_O]

Hi there,

Chiming in — I hope you got the answer you're looking for. Please feel free to let us know if you still have questions in mind, as we'll be willing to help. 

I appreciate the input, Emerson.

Best,

Jenelyn

[Shamrocks24]

Based on the above, I understand I need separate Nest Pwer Connectors for each zone.

The last dilemma is identifying separate C blocks. I think I have located them. See attachments.

 Does this look correct?

[RenzJ]

Hi everyone,

@Shamrocks24, I'd like to jump in here and see how I could help. To avoid confusion with the wiring, a wiring diagram would help you locate the correct terminal for each wire. If you do not have it on your HVAC cover or control board front, it might be on the user manual for it.

If you´re still having a hard time locating the correct terminals, we suggest you contact Nest Pro to help you out with installation.

Let me know if you have any additional questions.

Thanks for the help here, Emerson and Jenelyn.

Best,

Renz