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Nest and other such thermostats, 2 wire system

469 Views 6 Replies 5 Participants Last post by  More Power!
I have a traditional cold start boiler with a 2 wire system. I do have one internet thermostat, but it's a beast, ethernet cable, big module on the boiler, etc. and a hideous outdated app and website, so I'd like to go wi-fi and put "nest like" tstats throughout (I have 3 zones). I've heard that Nest tstats can "rob" power from the boiler (electricity) for charging its battery, and that this "robbing" can interfere with the firing of the boiler from time to time. I believe my electrician says we can fix this by running a separate "c" or "power" wire, which adds a little to the labor but not too onerous.

Does anyone know of some other alternative "simpler" solutions with other WiFi thermostats?

Thank you!
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Is there a reason that you need the wifi capabilities? I get it if this is a rental property and you want to spy on what your tenants are setting their heat to, or if you go out of town frequently and want to monitor things to make sure your pipes don't freeze.

Other than those reasons, I think you should quit trying to mess with your thermostat all of the time and just leave it set to one temperature and forget about it. Find a simple heating only thermostat that doesn't require batteries or a "C" wire. The cheaper the better. Don't spend more than about $25 on it.

Boilers take a long time to heat up a space. They work best when they are allowed to coast along at a single house temperature. You won't be saving much money or accomplishing much by programming in a setback.

If your goal is to save money, check into an "outdoor reset" control if you don't have one already. What they do is they tell the boiler to maintain hotter water temperature when it is colder outside, but cooler water when it is more mild. Your house temperature stays the same, but the boiler water varies to be only what is needed.

So as far as a thermostat, I recommend this one....

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Well in that case I'm sorry I yelled at you. You will need the common wire, and then you can pick pretty much any thermostat you want.

As others have said, I would stay away from nest though. The RTH6580WF from Honeywell would probably be a solid choice.
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