Wiring a central A/C is very easy, once you are told how.
Things You'll Need
- Phillips screw driver
- Small level
- Wire strippers
Turn breaker of to air handler or central furnace. Even though the voltage is only 24 volts ac, it is always better to work with the power off.
Begin by removing the old thermostat, pulling the cover off and then unscrewing the sub base and removing wires from the thermostat, then remove the thermostat base by removing the screws fastening it to the wall.
Now place the new thermostat against the wall and run the wires through the middle opening of the new thermostat. Fasten the thermostat to the wall with the screws included with the new thermostat, Use a bubble level to make sure the thermostat is level.
Now attach the sub-base to the thermostats base, this is done by placing the sub_base over the mounted base and finding the small screws attached too the sub-base, there are usually three screws.
Now it is time to attach the wires to the sub-base. On the sub-base you will see the letters r,(may have RC and RH) w, g, y, and maybe bl, bk, or, w1, w2, y1, y2. You will not need the later unless you are dealing with a heat pump, if your central A/C is a strait heat/cool A/C you only need the first four. Take the red wire and strip off about 1.4 inch of the wire insulation, back off the screw on the thermostat that is labeled "R" or "RC". make sure there is a jumper wire between RV and RH if your thermostat has these letters, if so then wrap the wire around the screw in a clock wise motion around the R or RC screw. Now screw the head of the screw down firmly making sure the bare end of the wire is not touching any other post. If there is no jumper from the RC and the RH, then you must create a jumper wire, this can be dun by attaching the red wire first to the RC then stripping away a bit of the red wire and placing it under the RH screw and tightening it down. Now take the Yellow wire (if you do not have a yellow wire, that's ok, some thermostat wire uses a blue wire instead of Yellow, just use the blue wire) and strip the end like you did for the red wire and wrap it clockwise around the Y screw and tighten down, Do the same to the white wire to the W screw and the Green wire to the G screw. Now place the cover over the thermostat and turn the breaker on. Your thermostat should now control you central A/C.
Tips & Warnings
- There should be a wiring schematic in your new thermostat box.
- make sure the thermostat you buy is for the kind of unit you have, if your A/C is not a heat pump, then do not buy a thermostat for a heat pump
- Always Always work with all power off. Never try to wire any electrical device hot.
How to Install an Air Conditioner
When installing a window air conditioner, following the instructions that came with the unit is important, because different units have different requirements.
How to Install Central Air Conditioning
Most people have central air conditioning, especially if they live in a warm climate. The common misconception is that you have to...
How to Size Wire for a Central Air Conditioner
Sizing the correct wire for any electrical device is regulated by the National Electrical Code (NEC). Local regulations may exceed the NEC...
How to Wire an Outside AC Condenser
An air conditioning system uses the outside condensing unit to force liquid refrigerant through a metering valve, found in the inside unit's...
Digital 4-Wire Thermostat Troubleshooting
In most homes, a digital 4-wire thermostat controls the heating and air conditioning (HVAC) system by sending a signal to turn on...
How to Wire an Air Conditioning Thermostat
Air conditioners are activated through the use of a thermostat. Older houses used mercury switches but modern construction uses digital thermostats. Installing...
Wiring Instructions for a Rheem 5-Wire Condenser Fan Motor
New, Rheem central air conditioners' condenser fan motors come with a five-wire setup. The older condenser fan motors had only three wires....
How to Wire a Nordyne Thermostat
Nordyne manufactures a complete line of heating and cooling products. The company's product line includes split-system air-conditioners and heat pumps, furnaces, packaged...
How to Wire an RV Thermostat
Coach thermostats in recreational vehicles, or RVs, fulfill the same purpose as thermostats in regular "sticks-and-bricks" houses. They control the output of...
Intertherm Air Conditioner Wiring
Intertherm is a brand of the Nordyne company. The Intertherm brand produces a limited number of products, including split systems. Split systems...
Connecting Home Air Conditioner Electrical Wires
Put the lock nut back on when connecting air conditioner electrical wires. Learn how to connect electrical wires on an air conditioner...
How to Wire a Digital Thermostat
Wiring a digital thermostat is fairly simply as long as the order of the wires match the furnace installation. Install the proper...