What Is Wiresaver?

Honeywell Proprietary

Honeywell.com

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Honeywell’s Thermostat

Wire Saver

• What does Honeywell’s wire saver do?

The wire saver (AKA: THP9045 Wiring Module) is designed to

be used with applicable thermostats in which a 24V common

wire is required but the homeowner does not have a common

wire connected to their current thermostat. The required wire

24V common wire powers the thermostat. Honeywell’s wire

saver acts like a splitter and replaces the need for a 24V

common wire to be run from the HVAC system to the

thermostat.

• When is a wire saver needed? How do I know if I need one?

It is needed if a homeowner does not have a common wire. Some homes have a

common wire – in that case using the wire saver is unnecessary. To check, carefully

remove the face of the existing thermostat (please refer to your thermostat owner’s

manual first). Look to see if a wire is currently connected to the C terminal [common

wire] on the current thermostat – of if extras are tucked away in the wall.

• How does the wire saver work?

It re-routes existing wires to ‘create’ a common wire. For example, on a basic 1H/1C

conventional system with 4 wires (R, W, Y & G) from the system to the thermostat: Y

& G are combined so one of the wires is moved to K and the other is moved to C.

• How do I install my thermostat using a wire saver?

Refer to your on Honeywell Z-wave thermostat installation manual. Essentially you

do a “normal” thermostat installation by installing the existing wires to the respective

thermostat terminal locations. Using the wire saver requires an extra step. This extra

step requires accessing your HVAC equipment to install the wire saver module. If

you have a common wire you don’t need to use the wire saver at all.

• Which Honeywell thermostats will the wire saver work with?

TH8320ZW series

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Honeywell.com Honeywell’s Thermostat Wire Saver • What does Honeywell’s wire saver do? The wire saver (AKA: THP9045 Wiring Module) is designed to be used with applicable thermostats in which a 24V common wire is required but the homeowner does not have a common wire connected to their current thermostat. The required wire 24V common wire powers the thermostat. Honeywell’s wire saver acts like a splitter and replaces the need for a 24V common wire to be run from the HVAC system to the thermostat.