Robertshaw 8625 Owner's Manual

1

Application

The Robertshaw 8625 is a multi-stage thermostat designed to control
24 VAC heat pump systems.

Features

• Large backlit display.

• Four preprogrammed E

NERGY STAR

®

setpoints for each day of the week.

• Adjustable 1

st

stage temperature differential: 1.0°F to 3.0°F (0.5°C to

1.5°C).

• Adjustable 2

nd

stage temperature differential: 1.0°F to 6.0°F (0.5°C to

3.0°C).

• Adjustable 2

nd

stage delay (10-40 minutes).

• Energy Efficient Recovery (EER™).

• Residual cooling for added air conditioning efficiency.

• Zone compatible as master thermostat.

• Fahrenheit/Celsius display option.

• Programmable from 45°F (4°C) to 90°F (32°C).

• Accuracy within ± 1 degree.

• Separate heating and cooling programs.

110-1101B

5 - 2 Day Programmable
2 Heat / 2 Cool

User’s Manual

Quick Start
Installation and
Programming

W

A

R

R

A

N

T

Y

2

T

W

O

Y

E

A

R

DIGITAL
PROGRAMMABLE
THERMOSTAT

8

62

5

ELECTRIC

E

GAS

G

OIL

O

®

NeW

HEAT PUMP

H

As an ENERGY STAR®partner, Invensys Controls Americas has determined
that this thermostat meets the ENERGY STAR®guidelines for energy efficiency.

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110-1166 6/8/05 9:15 AM Page 1

WARNING:

• Always turn off power at main fuse or circuit breaker panel before
installing, removing, cleaning, or servicing thermostat.

• Read all the information in this manual before installing this thermostat.

• DO NOT CONNECT TO 120 VAC. This is a 24 VAC low-voltage
thermostat. Do not install on voltages higher than 30 VAC.

• All wiring must conform to local and national building and electrical
codes and ordinances.

• Do not short (jumper) across terminals on the gas valve or at the
system control to test installation. This will damage the thermostat
and void the warranty.

• Do not connect ground to any terminal in this unit.

Recycling Thermostat

If this thermostat REPLACES a thermostat that contains mercury,
DO NOT discard the old thermostat in the regular trash. Mercury
is harmful to humans and the environment. For this reason, do
not open, break, or crush the mercury cell. If mercury leaks from
a damaged cell, DO NOT touch or handle mercury with bare
hands. Use protective, non-absorbent gloves to place mercury
into a sealable container. Fill the container with sand or another
absorbent material and seal the container completely.

Return the mercury or mercury products, in a sealed container, to
Invensys Controls Americas or a local recycling center for proper
disposal. If you have any questions, call Robertshaw technical
support at 1-800-445-8299.

Invensys Controls Americas
28C Leigh Fisher Blvd.
El Paso, TX 79906
Attn: Mercury Recycling Center

Step 1: Replacing Existing Thermostat

Wiring Table

Old Terminal New Label Description

R, V-VR or VR-R R 24VAC, return

Y, Y1, M Y1 Compressor relay (Stage 1)

O or R O Reversing valve (cool active)

B B Reversing valve (heat active)

F or G G Fan control relay

Y2 Y2 2ndstage cooling circuit

W2, W-U or E W2/E 2ndstage heating control or

emergency heating for heat pumps

C, X or B C 24 VAC, transformer common side

L or X L System monitor

W or W1 W1 1st stage heat - non heat pump

NOTE: THIS THERMOSTAT REQUIRES A 24 VAC COMMON WIRE FOR PROPER OPERATION.

NOTE: ON SOME OLDER MODELS, THE C TERMINAL CAN BE EITHER THE COOLING CONTROL OR
THE COMMON SIDE OF THE TRANSFORMER. CHECK FURNACE WIRING DIAGRAM TO VERIFY C
TERMINAL. IF IT IS THE COMMON SIDE OF THE TRANSFORMER, CONNECT TO THE C TERMINAL.

2

!

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WARNING:

In heat pump applications, do not connect anything to the W1
terminal. When switched to HP mode, W1 is connected internally
to Y1 on the thermostat. Connect AUX heat to the W2/E terminal.

1. Turn off power to heating and cooling system.

2. Remove cover of old thermostat to expose wires. Do not
disconnect wires. (See Figure 1)

3. Label wires per the Wiring Table.

4. After labeling wires, remove wires from terminals.

5. Remove existing thermostat base from wall.

6. Refer to the following section for instructions on how to
install thermostat.

Figure 1

Installing Item 8625 Thermostat

NOTE: FOR NEW INSTALLATIONS, MOUNT THERMOSTAT ON AN INSIDE WALL, 4-5 FEET

ABOVE THE FLOOR

. DO NOT INSTALL BEHIND A DOOR, IN A CORNER, NEAR AIR VENTS,

IN DIRECT SUNLIGHT, OR NEAR ANY HEAT OR STEAM GENERATING FIXTURES. INSTALLATION
AT THESE PLACES WILL AFFECT THERMOSTAT OPERATION

.

1. Turn power off to the heating and cooling systems.

2. Place EMER-HEAT-OFF-COOL in OFF position.

3. Place AUTO ON switch
into AUTO position.

4. Remove the cover using a coin
or screwdriver (see Figure 2).

5. Place thermostat against the
wall at desired location. Make
sure wires will feed through
opening on base of thermostat.

3

h

e

a

t o

ff c

o

o

l

h

o

ld

v

a

c

p

r

o

g

r

u

n

/s

e

t

h

o

ld

te

m

p

c

lo

c

k

s

e

t

a

u

to

o

n

M

O

N

°

F

select

set

MON

°

F

onauto

cooloffemer heat

Figure 2

!

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cooloffemer heat

MON

temp

prog

hold

select

°

F

vac

set

onauto

6. Mark placement of mounting holes (see Figure 3). Set base aside.

7. Drill the marked holes using a 3/16” (5mm) drill bit. NOTE: Enclosed
plastic anchors do not require a drilled hole for drywall.

8. Tap plastic anchors into the wall.

9. Align base with plastic anchors and feed wires through opening (see
Figure 3).

10. Secure base to wall with supplied screws.

11. Connect wires to terminal strip. Refer to wiring diagrams on page 5.
Make sure wire connections are secure.

12. Place Electric/Gas switch into either the ELEC or GAS position
depending on the type of furnace (see Figure 3).

13. Place the HP option switch into either the NON_HP or HP position
depending on the type of system you are using (see Figure 3). Use
the HP position for heat pumps ONLY. Use the NON_HP setting for
everything else.

14. Replace cover on thermostat by snapping into place.

15. Turn on power to system. Test thermostat as described in the
section To Test Thermostat.

4

Mounting Holes

ELECTRIC/GAS SWITCH
Selects fan control.

HP OPTION SWITCH
Heat pump switch.

Figure 3

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MON

GOB Y1W1

C

R

L

Y2

W2/E

°

F

Wiring Diagrams

The following is just a sample of the most common types of HVAC
systems. Refer to your system’s installation manual for wiring information.

5

Hot

Heating
Control

Cooling

Control

Transformer

T
H
E
R
M
O
S
T
A
T

W1

C

R

Y1

G

O

B

24 VAC

120 VAC

HEAT/COOL

4-WIRE

SINGLE TRANSFORMER

Fan

Control

Y2

W2/E

Hot

Heating
Control

Transformer

24 VAC

120 VAC

HEAT ONLY

2-WIRE

SINGLE TRANSFORMER

W1

Y1

G

T
H
E

R
M
O
S

T
A

T

O

B

C

R

Y2

W2/E

HEAT/COOL

2 STAGE

Hot

Transformer

24 VAC

120 VAC

T
H
E

R
M
O
S

T
A

T

R

C

L

W1

Y1

B

O

G

Y2

W2/E

First Stage

Cool

First Stage

Heat

Second

Stage Heat

Second

Stage Cool

Fan

Control

Hot

Cooling
Control

Fan

Control

Transformer

24 VAC

120 VAC

COOL ONLY

3-WIRE

SINGLE TRANSFORMER

W1

Y1

G

T
H
E
R
M
O
S
T
A
T

O

B

C

R

Y2

W2/E

Hot

Heating

Control

Fan

Control

Transformer

24 VAC

120 VAC

HEAT ONLY

SINGLE TRANSFORMER

3-WIRE

W1

Y1

G

T
H
E
R
M
O
S

T
A

T

O

B

C

R

Y2

W2/E

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