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Install guide GT5020
Install guide GT5020
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Install guide GT5020
To avoid electrical shock and to prevent damage to the furnace, air conditioner,
Caution
and thermostat, disconnect the power supply before beginning work.
This can be done at the circuit breaker, or at the appliance.
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1
Tools
You will need #1 Phillips screwdriver (small) and
Drill with 3/16-in. (4.8mm) bit for this installation.
1 Location
On replacement installations, mount the new thermostat in place of the
old one if possible.
On new installations, follow the guidelines listed below.
Locate the thermostat on an inside wall, about 5 ft. (1.5m) above the
floor, and in a room that is used often.
Do not install it where there are unusual heating conditions, such as: in
direct sunlight; near a lamp, radio, television, radiator register, or
fireplace; near hot water pipes in a wall; near a stove on the other side
of a wall.
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This thermostat does not require leveling.
Do not locate in unusual cooling conditions, such as: on a wall separating
an unheated room; or in a draft from a stairwell, door, or window.
Do not locate in a damp area. This can lead to corrosion that will shorten
thermostat life.
Do not locate where air circulation is poor, such as: in a corner or an
alcove; or behind an open door.
Do not install the unit until all construction work and painting has been
completed.
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Good
5ft.
(1.5m)
C A U T I O N
Your thermostat is a precise instrument.
Please handle it with care.
Turn off electricity to the appliance before installing or
servicing thermostat or any part of the system. Do not
turn electricity back on until work is completed.
Do not short (jumper) across electric terminals at
control on furnace or air conditioner to test the system.
This will damage the thermostat and void your warranty.
All wiring must conform to local codes and ordinances.
This thermostat is designed for use with 24 volt AC and
millivolt systems. The thermostat should be limited to a
maximum of 1.0 amps; higher amperage may cause
damage to the thermostat.
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2 Remove old unit
IMPORTANT : LABEL ALL WIRES
Switch electricity to the furnace and
air conditioner OFF;
then proceed with the following steps.
Remove cover from old thermostat. Most are snap-on types
and simply pull off. Some have locking screws on the side
or front. These must be loosened. Note the letters printed
near the terminals. Attach labels (enclosed) to each wire for
identification.
Read instructions carefully before removing any wiring from existing thermostat.
Caution
Wires must be labeled before they are removed. THERE IS NO STANDARD
COLOR CODE. When removing wires from their terminals, ignore the color of the
wires since these may not match the letter.
Label the wires one at a time. You must have all the wires labeled
before you proceed. With all wires labeled, remove them from the old unit.
BEFORE DISCONNECTING THEM!
W
G
B
Make sure the wires do not fall back inside the wall. Wind them around a
pencil to keep them from falling.
Loosen all screws on the old thermostat and remove it from the wall.
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Fill wall opening with non-combustible insulation to prevent drafts.
3
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3 Mount the GT5020
Separate front from back of unit. Press up on the
catch on bottom of thermostat and swing the body
away from the base, lift up to remove the body from
the base.
Hold the base against the wall, with the wires
A
G
Y
W
RH
B
O
RC
W2
C
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coming through the opening below the terminal block.
Position the base for best appearance.
Attach the base to the wall with the two
screws provided.
If you are mounting the base to sheet rock
or if you are using the old mounting holes,
use the plastic anchors provided. Drill a
3/16-in.(4.8mm) hole for the insert at each
screw location, then mount the base.
Thermostat Base
C
W2
RC
Terminal
Block
A
G
Y
W
RH
B
O
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4 Gas-Electric Selection
REFER to the back of the Control Unit
If you have Electric Heat or a Heat Pump you must place the Gas/Electric jumper in the ELECT
position (thermostat controls the Fan).
If you have Gas Heat the Gas/Electric Jumper should be in the GAS position (furnace controls
the Fan).
5 Heat Pump Differential
I
f your heat pump has auxiliary
heat, select the DIFFERENTIAL
jumper. This controls how often
your auxiliary heat will come on.
'2' is most comfort (cold climates)
'4' is most efficient (warm climates)
The unit must be reset when a
jumper is changed.
Inside of Unit
GAS
ELECT
Gas/Electric jumper
Calibration switch
AAAA AA
DIFFERENTIA
OFF ON
ADJ RM TEMP
Fahrenheit
/Celsius jumper
4
3
2
OPEN F
SHORT C
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6 Install Batteries
The GT5020 requires batteries to operate your system
and retain its programming in memory.
.
Switch MODE switch to OFF and the FAN switch to
AUTO.
.
Insert 2 AA alkaline batteries according to the
polarity noted in the compartment.
.
Press the RESET button to clear the transient
program memory. Initially, LCD display will go off.
NOTE: Replace the batteries when this LOW battery indicator appears on the display or once a year.
With batteries removed, you have approximately 30sec before your custom programming is lost.
7 Power Options
1) The GT5020 can run on batteries only. (2AA Alkaline)
The batteries will last well over 1 year. If the batteries are not replaced the thermostat
will stop working.
2) The GT5020 can run on the C wire if available. (24 VAC ONLY)
Please be aware of the following power options
AAAA AA
As shown in the wiring diagrams, The C wire is the other side of the 24VAC heating transformer. If the
C wire is used, the batteries are for AC power loss only and are not required.
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Page 8
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8 Wire Connections
Make sure your wires are labeled. This is necessary to determine which step-by-step wiring
diagram you should use. This may require you to find the 'other end' connection for each wire on
your heating or air conditioning equipment and read the label there.
If you have a Zoned Heating/Cooling system with multiple thermostats, please refer to our website
at www.Gemtech-thermostats.com for installation notes.
Before you Connect Wires
Please refer back to these guidelines for safe and secure wire connections.
.
Take care not to damage the labels for each wire in handling.
.
Strip insulation 3/8 in. (9.5mm) from wire ends.
.
Connect labeled wires only to a terminal with corresponding letter.
.
Bend the wire slightly, insert the wire under the contact plate and tighten
the screw down onto the wire.
What Wires Do You Have?
The Wire chart shows wire labels used on
Gemtech thermostats. Please determine what
wires you have and select the correct wiring
diagram to "go to" on pages 9.
Caution
each other or parts on unit.
Wires must be routed through
the hole in the back plate, below
the terminal block, or they will
hit parts on the cover.
Do not allow
wires to touch
Page 9
The Wire Chart below will help you determine the terminal connections you will use
on your new thermostat. See chart section that applies to your heat/cool system.
OLD THERMOSTAT NEW THERMOSTAT DESCRIPTION
R or RH or 4 or V RH or RC(leave jumper) Power Wire
ONE
Power
Wire
RH or 4 or V RH (remove jumper) Power Heat
TWO
Control wires
HEAT
ZONED
RC or R RC (remove jumper) Power cool
Power
Wires
W or H W Heat return
Y or M Y Cool return (compressor)
G or F G Fan return
C or X C AC source for thermostat
W2 or H2 W2 2nd stage of heat
Y2 do not connect 2nd stage of cool (n/a)
W2 W2 Heat pump Aux heat
E Do not connect
O (see note below) O Dmpr/Chg-over (pwr in cool)
PUMPS
B (see note below) B Dmpr/Chg-over (pwr in heat)
5 or R RH Power wire (pwr)
4 or W W Turn Valve on
MOTOR
VALVES
6 or Y or B A Turn Valve off
R RH Power wire (pwr)
Y or B W Turn Valve off
ZONED
W A Turn Valve on
SOLENOID
VALVES
Note: On a heat pump, if O and B are both present, connect O to O and tape off B.
For wiring support visit our website at www.Gemtech-thermostats.com
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NOTE: Wires marked with dotted line are optional.
From Furnace
R
or
RH
From Furnace
G
RH
or R
From Furnace
And AC unit
R
or
Y
From Furnace
And AC unit
Y
RH
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9
C
W
Go To Page 12
C
Go To Page 13
From heat pump
with out Aux heat
B
C
G
R
Go To Page 16
W
O
or
Y
RH
C
G
W
Go To Page 14
From heat pump
with Aux heat
C
C
W
Go To Page 15
W or W2
Y
O or
B
G
R
Go To Page 17
RC
G
If you do not find the wiring information for your system try our website: www.Gemtech-thermostats.com.
Page 11
8 Wire Connections cont
When you have finished connecting the wires attach control unit to wall
unit. Hook the top of the body onto the base, swing the body down, and
snap the body onto the base.
9 Check Unit
To check HEAT mode:
.
Set the mode switch to HEAT. Set the fan switch AUTO.
.
Using the TEMP UP button raise the set point to 90deg.
.
Allow the system 5 min to respond.
.
Verify that heat is blowing from the system.
.
Set the mode switch to OFF.
To check COOL mode:
.
Set the mode switch to COOL. Wait 5min for compressor delay.
.
Press the TEMP DOWN button to a temp 5o below room temperature.
.
Allow the system 5 min to respond.
.
Verify that cool air is blowing from the system.
.
Set the mode switch to OFF.
To check Fan:
.
Switch mode to OFF during fan test.
.
Switch the FAN switch to the ON position. Verify air is blowing from vents.
.
After test, return fan switch to AUTO, and mode to HEAT or COOL.
Follow these procedures to verify you
have correctly installed the unit.
TEMP UP
button
TEMP DOWN
button
A
G
Y
W
RH
B
O
RC
W2
C
Mode Switch
Fan Switch
Congratulations, you have successfully installed your unit. Please proceed to the OPERATING GUIDE
to initialize the new thermostat. REMEMBER, Mode switch must be in HEAT or COOL to operate.
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Page 12
GT5020 Features
The GT5020 can be used with most 24 volt gas, oil or electric heating and air
conditioning systems, heat pumps or gas millivolt heating systems. It cannot be
used with 120 volt heating systems.
The GT5020 is digital. You can set your desired
Heat and cool temperature set points directly on
the Large LCD display.
You can easily override the set temperatures.
4-minute minimum off time in COOL protects
your air conditioning system from being
damaged.
Two "AA" batteries (not included) are used to retain your time
and temperature programs, and to run the thermostat.
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Page 13
From Furnace
R
or
RH
2 WIRE
Thermostat
jumper
wire
C
FURNACE
R
HEAT
Power
W
HEAT
C
W
NOTE: Wires marked with
the dotted line are optional.
STEP 1 - Connect the R (or RH) wire to the RH terminal on the
thermostat. This connects to the Heater Power.
STEP 2 - Connect the W wire to the W terminal on the thermostat. This
connects the heater control line to the thermostat.
Your heater is now connected to the thermostat.
Go To Page 10
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Page 14
From Furnace
G
RH
3 WIRE
Thermostat
or R
PG
13
jumper
wire
C
RH
Heat
Power
FURNACE
Heat
C
W
NOTE: Wires marked with
the dotted line are optional.
STEP 1 - Connect the R (or RH) wire to the RH terminal on the
thermostat. This connects to the Heater Power.
STEP 2 - Connect the W wire to the W terminal on the thermostat.
This connects the heater control line to the thermostat.
STEP 3 - Connect the G wire to the G terminal on the thermostat.
This connects the Fan to the thermostat.
Your system is now connected to the thermostat.
Go To Page 10
W G
FAN
Page 15
From Furnace
and AC unit
Y
RH
or
R
STEP 1 - Connect the Y wire
to the Y terminal on the
4 WIRE
thermostat. This connects to
W
G
the Cooler compressor.
jumper
wire
C
STEP 2 - Connect the RH or R wire to the RH
terminal on the thermostat.
This connects the Heater/Cooler Power.
C
RH
Heat
Power
HVAC SYSTEM
W
Heat
STEP 3 - Connect the W wire to the W terminal
on the thermostat.
This connects to the heater control line.
NOTE: Wires marked with
the dotted line are optional.
STEP 4 - Connect the G wire to the G terminal on the Thermostat.
NON-HEAT PUMP
Thermostat
Y
Cool
Comp
FAN
G
PG
This connects to the Fan.
Go To Page 10
14
Your HVAC system is now connected to the thermostat.
Page 16
From Furnace
and AC unit
Y
STEP 1 - Remove the Jumper wire.
5 WIRE
NON-HEAT PUMP
Thermostat
STEP 2 - Connect the Y wire to the
Y terminal on the thermostat. This
connects to the Cooler compressor.
C
RH
RC
G
W
STEP 3 - Connect the RH wire to the
RH terminal on the thermostat. This connects to the
Heater Power.
STEP 4 - Connect the RC wire to the RC terminal
on the thermostat. This connects to the Cooling Power.
C
COOL
Power
HEAT
Power
NOTE: Wires marked with
the dotted line are optional.
STEP 5 - Connect the W wire to the W terminal on the thermostat.
This connects to the heater control line.
STEP 6 - Connect the G wire to the G terminal on the Thermostat.
Remove
jumper
wire
RHRC
W
Heat
HVAC SYSTEM
Cool
Comp
Y
G
FAN
PG
This connects to the Fan.
Go To Page 10
Your HVAC system is now connected to the thermostat.
15
Page 17
From heat pump
w/o Aux heat
Y
O
STEP 1 - Connect the G wire to
the G terminal on the thermostat.
This connects the Fan.
or
STEP 2 - notice jumper wire
between W and Y.
C
B
G
STEP 3 - Connect the Y wire to
R
the Y terminal on the thermostat.
This connects the Compressor.
STEP 4 - Connect the O or B wire to the O or B
terminal on the thermostat. (If you have both O and B
wires, use the O and tape off the B.) This connects
the change over valve.
HEAT PUMP
w/o Auxiliary Heat
jumper
wire
Thermostat
O or B
C
Single Stage HEAT PUMP
R
24VAC
Power
jumper
wire
O or B
Change
Over
Y
Comp
G
FAN
PG 16
STEP 5 - Connect the R wire to the RC terminal on
the Thermostat. This connects to the 24vac power.
Your HVAC system is now connected to the
thermostat.
NOTE: Wires marked with
the dotted line are optional.
Go To Page 10
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From heat pump
with Aux heat
W
or
W2
Y
STEP 1 - Connect the G wire to
the G terminal on the thermostat.
This connects the Fan.
HEAT PUMP
with Auxiliary Heat
jumper
wire
O
or
B
C
G
STEP 2 - notice jumper wire
between W and Y.
STEP 3 - Connect the Y wire to
the Y terminal on the thermostat.
This connects the Compressor.
R
STEP 4 - Connect the O or B wire to the
O or B terminal on the thermostat. (If you have both
O and B wires, use the O and tape off the B).
This connects the change over valve.
STEP 5 - Connect the R wire to the RC terminal on
the Thermostat. This connects to the 24vac power.
STEP 6 - Connect W or W2 to W2 on the thermostat.
This connects the AUX heat.
Thermostat
jumper
wire
O or B
Change
Over
HEAT PUMP
Y
Comp
G
FAN
C
24VAC
Power
O or B
(not both)
R
AUX
Heat
NOTE: Wires marked with
the dotted line are optional.
Go To Page 10
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Your HVAC system is now connected to the thermostat.
Page 19
Notes -
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Page 20
Customer Support website www.Gemtech-thermostats.com
1-507-013
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