Furthermore with heat only you likely will have a 24 volt hot and common red and blue a white wire for heat and a green wire for a fan. Note that in our case we had to use the green wire for c as discussed below because there were only four wires coming from.
C Wire Issues Hacking Your Way To Become A Thermostat Wiring
4 wire thermostat wiring diagram heat only. Httpsamznto2ojvow7 nest 3rd gen. Nest thermostat howto if your furnace isnt supplying power to your nest youll need this c wire transformer. A line voltage thermostat will typically have wires larger than 18 gauge and may not have terminal labels. Sensi thermostat is not compatible with line voltage systems. The basic heat ac system thermostat typically utilizes only 5 terminals. Boiler gas furnace radiant heat electric heat and air conditioning.
The common wire sometimes referred to as the c wire is whats responsible for delivering constant power to your thermostat. There are only four wires going into the existing thermostat red green blue white. There are a couple of options available to create a c wire and make the ecobee compatible. This is common for a digital thermostat that controls a boiler. In the most basic system this functionality is provided by use of a fan center relay and the low voltage wiring to the thermostat now will require a minimum of three wires for heat only units and four wires for heat cool fan for control. 4 wire or 5 wire thermostat wiring problem question.
This additional terminal is labeled g in the thermostat. Rc red wire power 24 vac rh or 4 red wire jumpered power 24 vac w white wire for heating enable y yellow wire for cooling enable. The blue brown or b lack wires also referred to as the c wire this wire connects the low side of the output of the low voltage power to the t stat. Heat only 2 wire boilerfurnace installations for ecobee thermostats. Thermostat installation wiring diagrams. Smartthermostat with voice control and ecobee4 wiring diagrams.
The diagram below shows how a basic 4 wire thermostat is connected as indicated by the color code chart above. It covers the same control or color features as the 5 wire thermostat wiring above except for heat only. We have both a natural gas furnace and an ac unit. Ecobee3 lite with 4 wire hot water zone valves. 3 wire heat only thermostat r g w installing your ecobee with a boiler and ac dual transformer system ecobee thermostat installation with an isolation relay. In this scenario the power extender kit pek is not compatible.
The red wire the red wire r rc rh connects the high side of the output of the control transformer to the t stat. Heat pump dual fuel geothermal. Heat pump systems include. We have a 19 year old condo with an old carrier mercury thermostat. Httpsamznto2vbs6gc if you found this. For programmable thermostats and smart thermostats c wires are essential for setting a schedule or having your heat or air conditioner turn on at a desired temperaturewhile some units can run without a c wire even brands like nest recommend having one for optimal.
3 wire heat only thermostat r g w if you have a heat only system you may notice that your thermostat has three wiresr g and w.
Gallery of 4 Wire Thermostat Wiring Diagram Heat Only
