Are nest thermostats really bad for furnaces?

[Tivall1]

I came across a guy who claimed that Nest Thermostats can fry the motherboards of furnaces and overwork the systems. He said that these smart thermostats might not play nice with certain heating units, causing premature failures or performance issues. Has anyone else heard of this happening? or is it just an overblown concern? I've been thinking about upgrading to a Nest, but now I'm wondering if it's worth the risk
Would love to hear your thoughts

 

[syncmyspace163]

There's been a lot of buzz about Nest thermostats damaging furnace motherboards, but it's mostly exaggerated. These thermostats are built to work well with nearly all standard HVAC systems, including furnaces, and they actually fit around 95% of them. That said, it's really important to check that your system is compatible and has the right wiring, like a C wire, for steady power supply.

 

[Khalil687]

I came across a guy who claimed that Nest Thermostats can fry the motherboards of furnaces and overwork the systems. He said that these smart thermostats might not play nice with certain heating units, causing premature failures or performance issues. Has anyone else heard of this happening? or is it just an overblown concern? I've been thinking about upgrading to a Nest, but now I'm wondering if it's worth the risk
Would love to hear your thoughts

It's a common rumor but @syncmyspace163 is right, it's mostly overblown!! That issue happens when a Nest is installed without a C-wire so it steals power from the furnace's control circuit to charge its battery. On some older or sensitive units, this process can stress the transformer or the main control board, leading to premature failure.. that's the source of the "fried motherboard" stories. So the simple fix is to just always install a C-wire or use the Nest Power Connector. This gives the thermostat dedicated power, stops the power-stealing, and resolves the risk!!