7 Wire Honeywell Thermostat Wiring Diagram [Full Guide]

If you got a new thermostat and want to learn about a 7 wire honeywell thermostat wiring diagram, then this is the perfect guide for you.

A thermostat with 7 wires is a typical one with a heat pump system, with auxiliary heat and or with a furnace.

Wire Color Codes For a 7 Wire Thermostat

WwhiteFor secondary hea
Y or Y 2yellowCompressor relay
GGreeen Fan relay
OOrangeReversing Valve
R (Rc or Rh)RedPower from the transformer
CblueCommon wire

White wire ( W)

The heat strip wire. This is the wire that is responsible for controlling the heat strip or the secondary heating also known as the emergency heat.

When the heat pump is unable to heat your home efficiently, the Emergency heat kicks on,  to supplement the heat pump’s heating/

Yellow (Y wire)

This is for the first stage compressor relay and controls the compressor. 

The Y wire is responsible for cooling and it should go on the Y terminal. Sometimes you may have Y1 and Y2 terminals Y2 is for the second stage compressor compressor relay. 

Read also: Coleman mach thermostat wiring

Green ( G wire for the fan)

The ground wire G is responsible for energizing the blower fan.

The blower fan is found in the air handler or indoor unit and is responsible for blowing the cooled or heated air. It pushes the air into the duct system so that it can reach the intended destination.

The G wire is important in the direction of heated or cold air and when it is not connected there could be overahing of your heating and the furnace will not heat your home.

Reverse valve (orange wire):

This wire is responsible for controlling the reversing valve on the heat pump system, it shifts between two positions . In one position it energizes heat  on heat and it energizes  cooling

What wires go where on a honeywell thermostat?

The reversing valve enables your heat pump to work as an air conditioner in times of cooling and as a heater in the heating system.

When your heat and cool are reversed it is the reversing valve setting that is setting to be set correctly.

Red ( R-wire)

The red wire can be Rc or Rh. Rc is power to cool and Rh is power for heating.  The R wire can go into either Rc or Rh terminal as there is usually a jumper between the two terminal

Blue  ( Common wire) 

This provides consistent power to the thermostat. Even if your thermostat has batteries, you may need the common wire to charge batteries. The thermostat with batteries can work without the c wire.

Read also: Honeywell Thermostat Wiring For Heat Pumps

Wiring diagrams for  a 7 wire honeywell thermostat

Before Wiring your thermostat, you need to know what kind of heating/ cooling system it is.

If it is a heat pump or conventional heating, does it have emergency heat or is an air conditioner? You’ll also need to know if its a 2 stage or single stage system.

You can find this information on the sticker labels on your equipment or you can look up the model numbers on the manufacturer’s website. You should then be sure about the system you have.

In general, there can be  about 4-5 systems that may need 7 wires. These include the following:

2nd Stage Furnace with 2nd stage  air conditioner (7 Wire)

Wire to be connectedFunction
Y1Compressor relay stage 1
Y2Compressor replay stage 2
W1Heat Relay
W2Heat Relay Stage 2 
GFan relay
CCommon wire
RPower for heating

2nd Stage Heat Pump with Aux heat (7 wire)

Wire to be connectedFunction
Y1Compressor relay stage 1
Y2Compressor relay stage 2
W2/AuxHeat relay stage 2
GFan relay
OReversing valve
CCommon wirePower 

2 Stage Heat Pump, 1 Stage Heat (7 wire)

Wire to be connectedFunction
Y1Compressor relay stage 1
Y2Compressor relay stage 2
W1Heat relay stage 1
OReversing valve
GFan relay
RPower from transformer
CCommon wire

1st Stage Heat Pump, 2 Stage Heat  (7 Wire)

Wire to be connectedFunction
Y1Compressor relay stage 1
W1Heat relay state 1
W2Heat relay stage 2
OReverse valve relay
GFan relay
RPower from the transformer
CCommon wire

Which wires on a honeywell thermostat are responsible for heating?

When there is calling for heating, the wires that are responsible for heating are the Y-wire, the compressor relay wires, and the G wire for the blower fan and the Rh( power for heating wires.)

In case your thermostat is not responding when you call for heat you can bypass the thermostat to determine if the problem is really with the thermostat or the system. To achieve this simple

Put together the the Y, G and R H wire. If the compressor kicks on outside, then the problem is probably not with the system but the thermostat. IAnd if the system doesn’t turn on heat, the problem is not with the thermostat.

Read also: 6 wire thermostat wiring diagram

Final thoughts

To wrap up, we hope you have understood how to wire your 7 wire honeywell thermostat with our example systems.

If you don’t know what type of system you have or you haven’t managed  to wire your thermostat, it is perhaps best to call a local professional for help.


More on thermostat wiring color codes: http://thermostating.com/thermostat-wiring-color-code-complete-guide/

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