Most thermostats are very low draw but to make sure look up the power requirements for each and add them together. Honeywell 48 VA powers 24V air conditioning circuits and other applications that do not exceed the listed ratings. 24V control circuit step-down transformer designed to power any 24V control system, including thermostats, gas valves and relays. HOME USE: Plug the transformer into your standard 110V /120V outlets and converts to 24 volt AC current. The lower voltage is sent to the push button to engage the chime mechanism. The class 2 transformer is without a fusible link or overload protection. Furnace 24 Volt Transformer R is the hot side while C is the common side of the transformer. White Black R 110-V Power Source 24-V Thermostat (p/n 8200008) RC Y B O RH G W Zone Valve Unit Bypass Main – Back to Outdoor Furnace C W R C NOTE Thermostats must be installed by quali˜ed technician. The two transformers will both be attached to R. If your transformer is out of phase with the furnace transformer, that means there would be 24v between your C and R, and another 24v between R and W when the furnace is off. Our Book https://www.acservicetech.com/the-book Installation and Wiring of a 24v Low Voltage Thermostat! The 24 VAC transformer is also employed in many thermostats for home heating, ventilation and air-conditioning systems. AT72. The two 24 volt wires go to the R terminal and C terminal inside the thermostat. Now compare that to the transformer wattage/ amperage. Step By Step! Wire your hot side of the 24v transformer to R on the Wi-Fi thermostat. The two 24 volt wires can NEVER touch or the transformer will short and need to be replaced. The problem you have adding a second transformer is phase. lead wires for primary connections that are color coded for your convenience. and doorbells (Ring, Nest Hello, Skybell, August) that require 24 volt power for operation Honeywel Transfomers are made for heating systems. AT87. The most common application for a 24 VAC transformer is to activate a doorbell chime. a 24-V Thermostat and a Transformer For illustration purposes only: • Location of thermostat may vary. Connect W on the thermostat to one side of the relay coil. 24V C WIRE POWER ADAPTER: plugs into your standard 110 v/120 v outlet and converts to 24 volt AC current 24 VOLT TRANSFORMER FOR THERMOSTAT AND DOORBELL: powers up smart thermostats for (Nest, Ecobee, Honeywell, Emerson Sensi, Hive, etc.) If less is needed from the 2 stats than the transformers rated output you are good to go. I have run multiple thermostats and even a 24v damper off a single transformer. The Honeywell 24 Volt transformer is designed to power 24 Volt control systems such as thermostats, gas valves and relays. This plate-mounted 120 VAC transformer has 9 in. On the other side of the coil you’ll add C from the thermostat, and common wire of the transformer. These Honeywell Transformers are the industry standard. So the thermostat would see 48V between C and W. Honeywell 40 VA transformers power 24V systems including thermostats, gas valves and relays.