Question regarding thermostat power stealing when there is no C connection, for any thermostat not just Nest. As far as I understand, the thermostat completes the heating relay circuit, and …

Dec 9, 2025 · Nest thermostats receive operational power directly from the low-voltage wires connecting them to the HVAC system, typically operating on 24 volts AC. For models installed …

Jan 5, 2025 · I also came across some posts on "power stealing: that indicate that all but the newest Nest Thermostats can steal/borrow power from the Heating Circuit (Rh) when there …

Learn about the common or C wire Nest thermostats are designed to use very little power, and in many cases they can use your system’s heating and cooling wires to get enough consistent …

Sep 2, 2025 · Phantom power steals and stores power from both the heating and cooling circuits in a super capacitor. This allows for the thermostat to work in applications without a common …

The Nest learning thermostat is a power stealing thermostat which can cause system malfunction or improper system operation. The solution is to add what is known as a common wire, this …

Apr 21, 2025 · The Nest Thermostat E and the Nest Learning Thermostat do not require a C wire. Both models can work without it by using the power from the heating or cooling wires.

Nov 13, 2018 · In a system with a C-wire, the Nest charges itself from the C-wire’s current and all is fine. In a system without a C-wire, though, Nest recharges its battery when the heating or …

Dec 23, 2019 · 2 wire thermostat, when does Nest power steal? I have a 3 zone (1 upstairs, 2 downstairs) baseboard radiant heating system with a gas burner. I have installed 3 nest E …

While Nest thermostats work with most 24V systems, there are some system types and models from various manufacturers that are incompatible. Others may need to have a C wire or the …