02-01-2025 06:57 AM
I have an infloor heating system using pipes. House is 16 years old and I have a two wire thermostat W and Rh. I have three of these and three zones. I have read many posts about the gen 3 working and not working without C wire. Running a Cwire from propane furnance is not practical so last attempt at some clarification on installing a gen 3 without a Cwire is needed. I have pics but not sure how to upload them
02-04-2025 11:50 PM - edited 02-05-2025 02:19 PM
Hi @Mrogers60,
Thanks for posting in the community. I understand you have a 16-year-old in-floor heating system with three zones, and you're considering a Nest Learning Thermostat (3rd generation). You're concerned about the C-wire requirement and the difficulty of running one from your propane furnace. You've also encountered conflicting information about the reliability of the Nest Learning Thermostat (3rd gen) without a C-wire in your situation, and you'd like some clarification. I can definitely help with that.
To best assist you, could you please provide pictures of your current thermostat wiring and the control panel on your heating system?
You can upload the pictures by clicking the camera icon when replying to this thread.
I’ll be waiting for your reply.
Regards,
Derick.
02-06-2025 04:21 AM
Hi Derick, i dont have the camera icon to add my photos
02-06-2025 04:25 AM
02-06-2025 04:26 AM
the camera icon showed after i replied to your first message
02-07-2025 12:04 AM
Hi there!
Thanks for your reply. I can see that your HVAC system meets the voltage requirements to install a Nest Learning Thermostat (3rd gen) or Nest Thermostat E; the C wire installation is recommended in some cases when the HVAC system can't provide constant power to the Nest Learning Thermostat (3rd gen) and it starts draining its battery.
For more information, you can take a look at the following articles: Learn about the common or C wire, Nest thermostat technical specifications.
I’ll be waiting for your reply.
Regards,
Derick.
02-07-2025 08:30 AM
Hi Derick so you are saying I can install the gen3 or do I need a Cwire. I went through the link and it’s says I can but there is conflicting information where the battery dies and not being able to charge it. I do not have access to use an adapter either due to location of the three thermostats I have to replace.
02-07-2025 11:20 PM
Hi there!
I appreciate your response. I can understand why you might be confused regarding the Nest Learning Thermostat (3rd gen) C wire need. Let me clarify this for you:
The Nest Learning Thermostat (3rd gen) can operate without a C-wire in most cases. It uses an ingenious technique to draw a tiny amount of power from your existing wiring even when the system is off. This keeps the battery charged.
However, in some specific wiring setups or with certain HVAC systems, this might not be enough to maintain the battery.
I’ll be waiting for your reply.
Regards,
Derick.
02-08-2025 01:09 PM
Thanks Derick and I appreciate your patience. So based on the pics I shared I should be good to install. do you agree. I will need to buy three gen3 thermostats. Thank you
02-08-2025 07:40 PM
Hi there!
Thanks for your reply. Yeah, the Nest Learning Thermostat (3rd Gen) should work with your HVAC system without any problem.
Feel free to continue posting if you have any other questions.
Best regards.
Derick.