Replacing thermostat by yourself without a Denver HVAC technician may be pretty harrowing if you do not hook up the wiring correctly. Inside of the thermostat there are various terminals which ought to hook up with the right wires. The R-terminal is the thermostat’s power. R means Red, the Colorado heating repairman will have to have red wires going to this terminal. This power comes from the transformer. The transformer is commonly in the condensing unit or the air handler in a split system. Because they are supplying power, it is a good idea to kill the power to both the condenser and the air handler before working on the thermostat.
The RC terminal is the power for cooling. Some big HVAC schemes have two transformers, one for cooling and one for heat. In such a case, the power from the ac system goes to the thermostat terminal. A jumper may be installed amongst RC and RH for a single transformer heating and cooling system. The RC terminal is likewise red.
The RH terminal is the heating power-in. This is likewise red and may be jumped to the RC.
The Y terminal is yellow and goes to the compressor relay. Some Denver HVAC specialists use a terminal board strip on the air handler control board which makes splices not needed. Y2 is commonly light blue and is the code for a second stage cooler. If you do have two compressors, both will have to work off the same thermostat. Most Denver heating and air companies do not need the cooling of a two stage company.
W is the heating terminal. W is for white terminal. This will have to go directly to your heating source, whether it be a furnace or boiler. W2 is for second stage heat and is commonly brown. This is for gas furnaces with low and high settings. Heat pumps use W2 for auxiliary heat.
G is for green and goes to the indoor blower fan relay.
C is for Common, and does not have a specific color though black is seen frequently. For digital thermostats that consume power, the mutual wire is necessary to finish the 24 volt circuit.
Orange “O” and “B” Blue are for heat pumps. Rheem and Ruud heat pumps use the B terminal for the cooling reversing valve. Other HVAC makers use the O terminal. Trane, Lennox, Goodman, Ducane, Heil, Carrier, Fedders, Amana, and Janitrol are normally hooked up to the O terminal by HVAC contractors in Denver.
E is for emergency heating. This has no frequent color but will have to be wired to the heating relay or E terminal strip board.
S1 and S2 are for outdoor air sensors. This has no popular color, but ought to use a shielded wire to reduce interference and the possibleness of water harm from outside. Warning: These colors are the defaults. The person wiring the thermostat could have used unconventional color coding.