Ecobee ecobee3 lite User manual

Installation guide

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Welcome!
If you have questions, we have answers.
Visit ecobee.com/Support/ecobee3 for tutorials, how-to
videos and FAQs.
Technical support is also available by email or by phone:
[e-mail]
1.877.932.6233 (North America)
1.647.428.2220 (International)
Compatible systems
ecobee3 works with most centralized residential heating
and cooling systems.
Heating: up to 2 stages
Cooling: up to 2 stages
Heat pumps: 1 or 2 stages + up to 2 stages auxiliary heat
Accessories: Dehumidifier, humidifier or ventilation device

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Items included in box
A
B
C
D
E
F
G
A
D
B
E
C
GF
ecobee3 thermostat with
back plate and trim plate
Remote Sensor and stand
Power Extender Kit
(optional)
Large trim plate
Screws and drywall plugs
Information booklets
Double-sided adhesives
wire labels
Installation Guide
Quick Start Guide

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A
B
A B
Phillips screwdriver
Drill for mounting anchors with ⁄ inch drill bit
Items you’ll need
Tip: Review all the instructions before you start to
ensure that there are no surprises during installation.
Tip: For accurate temperature readings, install your
ecobee3 in a conditioned space, on an interior wall, and
away from direct heat sources.

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Overview of steps
Installing your ecobee3 home climate system is easy. Just
follow these steps and you’ll be done before you know it.
Power o your HVAC system
Before doing anything else, power o your system.
Label the wires
Label each wire with the provided stickers.
Install Power Extender Kit
The PEK is not required for all installs. If you have a wire
labelled “C” or “common”, skip to step 4.
Attach back plate to wall
Secure the back plate to your wall with the provided screws.
Connect wires to ecobee3
Use the stickers from step 2 as a guide and insert the wires
into ecobee3 terminal blocks.
Power on your HVAC system
Power back on your HVAC equipment. Your ecobee3 will
automatically power on and guide you through setup.
Install remote sensor
Stand in front of your ecobee3 and pull the plastic tab
on the remote sensor to automatically connect it to your
thermostat.
Step 1
page 8
Step 2
page 9
Step 3
page 11
Step 4
page 14
Step 5
page 16
Step 6
page 18
Step 7
page 19

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Terminal descriptions
GFan
Rc Cool transformer
Rh Heat transformer
O/B Heat pump reversing valve
YY1, Y2: Used for 1 - 2 stages of conventional A/C
or 1 - 2 stages of heat pump compressor
WW1, W2: Used for 1 - 2 stages of conventional heat
or 1 - 2 stages of auxiliary heat with heat pump
C24VAC common
ACC Accessory (+/-): Used for dehumidifiers,
humidifiers, ventilators, HRVs or ERVs
Warning! ecobee3 is designed for 24VAC with a 2A
maximum current. Do not connect it to line (high)
voltage or millivolt systems.

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Step 1. Power o your HVAC system
Before doing anything else, power o your system. If your
HVAC equipment doesn’t have a master switch, go to your
circuit breaker box and turn o the breaker.
Verify that the equipment is o by attempting to
adjust the temperature at your existing thermostat. The
thermostat will show the temperature change but your
cooling or heating should not come on.
Power o your system either
using the master switch or at
the circuit breaker box.

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Step 2. Label the wires
Remove the cover from your old thermostat. Most snap o
easily but some may be attached by screws.
110/120V
Warning! If your old thermostat has 110/120V wires
capped with wire nuts, it is a high voltage system and is
not compatible with your ecobee3.
Note: If you don’t have an existing thermostat, skip to
step 3.
HC

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1. Look at the wires coming out of the wall. Take a
picture for reference.
2. Using the old thermostat base as a guide, label each
wire going into your old thermostat with the provided
stickers.
3. If you have used the wire label C, please skip step 3
and proceed directly to step 4. If you have NOT used
the wire label C, proceed to Step 3: Install Power
Extender Kit (PEK).
Discard any jumper wires
between Rh, Rc, or R. Your
ecobee3 does not need them.
Tip: If the wires have completely dierent labels, please
call ecobee support to help with wiring.
RCRHG Y W C

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Step 3. Install Power Extender Kit
(PEK)
Some thermostats do not have a C-wire. The C-wire is
used to reliably provide power to the thermostat. In this
case, the PEK can use the existing wires to power your
thermostat.
Warning! This step requires you to work with wiring at
your HVAC Control Board. If you are not comfortable
working with your HVAC wiring, contact ecobee
customer support or hire a professional installer.
Note: The PEK is not required for all installs. If you have
a wire labelled “C” at your thermostat, skip to step 4.
At your thermostatAt your utility closet
Existing
thermostat wires
Power
Extender Kit
HVAC
control board
R
G
Y
W
C
RCRH G Y W

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The PEK requires your system to have the following wires:
• 4 wires: W, Y, G, and R (or Rc or Rh), or
• 3 wires: Y, G, and R (or Rc or Rh)
1. Remove the cover panel from your HVAC equipment.
2. Locate the control board and take a picture of it for
reference.
3. Using the stickers provided, label the wires on the
control board leading to the thermostat.
Furnace (cover panel removed)
Tip: The control board will generally have R, G, Y, W, C
terminal designations.
Control board
Wires to thermostat
R
G
Y
W
C

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4. Open up the PEK. It has two rows of terminals (one
side is for thermostat connections, the other side,
pre-wired, is for the control board connections).
5. Disconnect the wires from the control board and
reconnect them to the corresponding terminals on the
thermostat side of the PEK.
6. Using the wires provided with the PEK, connect the
terminals on the equipment side of the PEK to the
corresponding terminals on the control board.
7. Close the PEK and use the provided double-sided
tape on the back to mount it in a dry location that
doesn’t strain the wires. The PEK can be safely placed
on any free space on an inside wall of your HVAC unit.
8. Close the HVAC cover panel.
Wires connecting
to thermostat
Power Extender Kit basePower Extender Kit cover
Y
W
G
C
R
W
G
R
Y
G
R
Y
W
Pre-installed wires
to HVAC control board

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Step 4. Attach back plate to wall
1. Gently remove the old thermostat base by unscrewing
it from the wall. Make sure the wires do not fall back
into the wall.
2. Position the back plate of your ecobee3 on your wall,
using the built-in level to make sure it’s straight. Mark
the mounting holes on your wall in pencil.
3. Drill mounting holes for the drywall anchors.
4. The back plate must be used with a trim plate.If the
smaller trim plate does not cover the marks left by the
previous thermostat, you can attach the larger trim
plate instead.
Remove the back plate by gently
pushing the back of its left side
towards you.

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Tip: ensure the back plate is straight by centering the
bubble on the built-in level.
Secure the back plate
Use the drywall anchors and screws provided to secure
the back plate to the wall.
Insert the back plate using the tabs
on the right as a guide. It will snap
into place when correctly inserted.

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Warning! If you installed the PEK in step 3, the R (or
Rc or Rh) wire must connect to the Rc terminal on the
ecobee3, or the thermostat will not power on.
Step 5. Connect wires to ecobee3
The wires from the wall should plug easily into the terminal
blocks. To release a wire, press down on the lever.
When installed correctly, the release lever of the terminal
block will lower to indicate engagement. Tug on the wires
to ensure they are engaged in the terminal.
Tip: If you are replacing an existing thermostat, use the
stickers as a guide when inserting the wires into the
ecobee3 terminal blocks.

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If you need help with the wiring, refer to the reference
diagrams at the back of this guide:
• For conventional heating and cooling systems, see
page 29.
• For heat pumps (air or geothermal), see page 30.
• For boilers or radiant heat systems, see page 31.
• For accessory devices like dehumidifiers, humidifiers,
or ventilators, see pages 32–35.
• For PEK installations, see page 36.
Attach thermostat
Push any excess wires back into the wall, and connect your
ecobee3 thermostat to the base.

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Step 6. Power on ecobee3
Power your HVAC equipment back on. Your ecobee3 will
automatically power on. If your ecobee3 does not power
on, see page 27 for troubleshooting.
Follow the on-screen instructions. ecobee3 will guide you
through the setup, which includes:
• Equipment configuration (HVAC and accessories)
• Set your preferences (choose °F or °Cheatingand
coolingsetpointsthermostatname)
• Set up wi-fi
• Register your ecobee3 online
hi
Tip: The settings on your ecobee3 can be changed at
any time from the main menu.

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Step 7. Install remote sensor
Ordinary thermostats only read the temperature in one
location. ecobee3 uses multiple temperature readings from
remote sensors to deliver comfort more reliably.
Pair the sensor at the thermostat
1. To activate your remote sensor, ensure your ecobee3
is awake by standing in front of it or touching the
screen.
2. Pull the plastic tab on your remote sensor and it will
power on and connect to your ecobee3 automatically.
Stand in front of your ecobee3
and pull the plastic tab on the
remote sensor to automatically
pair it with your thermostat.

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3. Your ecobee3 will detect your remote sensor and ask
you to name it. You can verify a successful connection
on your thermostat. If your sensor does not connect
with the ecobee3, simply remove the battery, wait
2 minutes, and re-insert the battery to restart the
detection process.
To access the battery, pop the
remote sensor back cover o
using the ridges provided.
To attach the remote sensor
stand, remove the smaller back
cover and pop the stand into
place.
To remove the remote sensor
stand, pull the base outwards.