How To wire a Smart Thermostat – Thermostat Wiring Tips

Thermostat plays an essential role in room temperature control for heating/cooling or heating and cooling, which allows people easily access central air conditioning system control from one or two location. Nowadays, smart programmable Wi-Fi thermostats are selling like hot cake around the world, but correctly wiring a thermostat and letting smart thermostat work is never easy for end users. Here Hotowell will explain how to wire a thermostat for some of the popular air conditioning systems.

There are many kinds of air conditioning systems, such as fancoil units system (FCU), VRF, VRV, Heat pump system, floor heating system, split air conditioning system and so on. Thermostats for different systems always have different wiring diagram, they usually cannot compatible with each other. Here we take FCU thermostat as an example to explain how to wire a thermostat. As FCU system is popular in commercial buildings and some residential buildings, which typically comes with fan and valve control to maintain a desire room temperature.

1.       Preparation before installing new thermostat

If the place has installed a thermostat:

l  Turn off the power, make sure thermostat and fancoil system are off position.

l  Detach thermostat cover, take a picture of the wiring connection of current thermostat

l  Label wires to indicate specific function(s)

If the place does not have thermostat installed, it is highly recommended to ask help from HVAC installation specialists or professional electrician.

2.       Install New Thermostat following steps shown in manual

For standalone fancoil thermostat, the wires are easy which always have 3 wires for fan speed control(High-mid-low), 1 or 2 wires for valve control(1 valve for heating only/cooling only; m2 valves for heating and cooling changeover), N and L terminals for line voltage inputs. Classic Tuya fancoil thermostat wiring is shown as below:

Typical steps:

Step1: power off current installed thermostat.

Step2: take off thermostat cover(shell), take a photo of current wiring connection of the thermostats, comparing wirings with new thermostat, and label wires correctly.

Step3: Disconnect each wires of installed old thermostat, unscrew thermostat to take off old back plate from the wall. Please tape and fix the wires to make sure they won’t fall into the hole before installing new thermostat.

Step4: Screw and fix new thermostat plate, connect each wire according to indicates labeled. Before putting thermostat cover in place, double check wires connections to make sure each one is in place.

Step5: Putting on thermostat cover and turn on the power. Then power on thermostat, check each function of thermostat which are shown in datasheet to test.

If every function works well, congratulation! You can get started to enjoy it.

Beside fancoil thermostat, below shows thermostat wirings for electric floor heating system and heat pump system, tips to wire this kind of smart thermostat, please refer to above 5 tips.

If interested to talk more in details, welcome to contact Ms. Tiana for more information.

Her contact as below:

Email: alpha@hotowell.com