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Nest Thermostat Boiler

Mdmcmahon
Community Member

I have a Nest Thermostat and a Boiler with a Hydrostat 3200. 

With an R&W connection it works fine, but doesn’t have enough battery power and can run through batteries. 

I tried adding the power connector, it had enough power, but wasn’t controlling the boiler at all, even though it confirmed it was connected to the R&W wire. The heat wouldn’t turn on. Tried resets etc. Restored it back to original, but wondered if anyone had a similar issue and was able to resolve it. 

12 REPLIES 12

CoolingWizard
Platinum Product Expert
Platinum Product Expert

I have only seen this when the power connector was not connected properly. Here’s what you need to understand about those type gas boilers in the gas valves and control control systems. Some boiler control systems are not 24V AC power based. In fact they just have a control circuitry that goes through a thermostat and when that 500mV gets back to the gas valve, it starts the boiler.  if your boiler has a 24V AC control system you will find a transformer and that would work. The 24V AC is needed to properly power the Nest Power Connector.

Ken, AC Cooling Wizard

NestPro, Google Pro, Mechanical Engineer and HVAC service company owner.
If my answer solved your problem, click Recommend this Answer below, and If it helped you, please give a Kudo.

Thank's for your response Ken. I can can definitely see there is a 24v connection, but unsure where I should connect a C-Wire to. The C wire is already run, I tried running it from the Z screw inside the hydrostat, but unfortunately it appears that is the low wattage you mentioned. (I didn't do any of the wiring or installation here, I am just hoping not to have to pay someone to come out for a few minutes of work.)IMG_3031.JPG

EdwardT
Community Specialist
Community Specialist

Hi folks,

 

@CoolingWizard, thanks for the help!

 

@Mdmcmahon, I wanted to follow up and see if you are still in need of any help. Please let me know if you are still having any trouble from here, as I would be happy to take a closer look and assist you further.

 

Thanks,

Edward

EdwardT
Community Specialist
Community Specialist

Hi Mdmcmahon,

 

It's me again. I wanted to check back in to see if you have other questions and concerns. Feel free to let me know if you do. 

 

Thanks,

Edward

Hi Edward, unfortunately not, we'll likely be contacting a local technician or replacing the nest with our old Thermostat. 

EdwardT
Community Specialist
Community Specialist

Hi Mdmcmahon,

 

Thanks for the update. Let us know the results once your system has been checked by a technician. Keep us posted.

 

Thanks,

Edward

Jhonleanmel
Community Specialist
Community Specialist

Hey there Mdmcmahon,

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

Best, 
Mel

Hi everyone,

Just one quick final check in here since activity has slowed down. We haven't heard from you in a while so we'll be locking this thread if there is no update after 24 hours. If you have any new questions, updates or just a discussion topic, feel free to start a new thread in the Community.

Thanks,
Mel

EdwardT
Community Specialist
Community Specialist

Hi folks,

 

@CoolingWizard, thanks for the help!

 

@Mdmcmahon, how's it going with your Nest Thermostat? Still need our help?

 

Thanks,

Edward

EdwardT
Community Specialist
Community Specialist

Hi Mdmcmahon,

 

It's me again. I wanted to check back in to see if you have other questions and concerns. Feel free to let me know if you do. 

 

Thanks,

Edward

Hi Edward, I unfortunately have not figured it out yet, even after staring at wiring diagrams for the boiler. 

CoolingWizard
Platinum Product Expert
Platinum Product Expert

The terminal marked 24Volt Ground should be your Common .

Ken

NestPro, Google Pro, Mechanical Engineer and HVAC service company owner.
If my answer solved your problem, click Recommend this Answer below, and If it helped you, please give a Kudo.