AccuAir AS7812 General instructions

AS7812
Non-Programmable
Electronic Thermostat
Installation, Operation & Application Guide
• Controls Single Stage Heating/
Cooling Systems
• Single Stage Heat Pump Systems
• Compatible with Gas, Oil or
Electric Systems
• Millivolt and Hydronic (water or
steam) System Compatible
• Mercury-Free, Environmentally
Safe

Table of Contents
Parts Diagrams .....................................................................................................1
Specifications ........................................................................................................2
Important Safety Information ...............................................................................2
Package Contents/Tools Required.........................................................................3
General Description...............................................................................................3
To Remove Existing Thermostat ..........................................................................4
To Install Thermostat ............................................................................................4
Replacing Wiring Labels ........................................................................................6
AS7812 Wiring Diagrams ......................................................................................7
A Quick Test........................................................................................................10
Operation ............................................................................................................11
Troubleshooting ..................................................................................................12
CAUTION! : This thermostat should be installed by trained technicians only. Adhere
to all local and national codes. Disconnect all power to the system before
installing, removing, or cleaning.

1
Parts Diagrams
AS7812
G O B Y C RW
NON HP–HP
GAS
ELEC
SC2001
Reset Switch
Electric/Gas
Jumper
Mode
Switch
Fan
Switch
Freeze
Switch
High Temp.
Switch
Non HP – HP
Jumper

2
Important Safety Information
Input:
• Voltage: 18-30 VAC
Output:
• Maximum: 1 amp per terminal (3 amp total for all terminals)
• Temperature control ranges: 45°F to 90°F Accuracy: ± 1°F
• Differential range: 1°F to 3°F
• System configurations: Single-stage heat, single-stage cool
or single-stage heat pump, gas, oil,
electric
• Terminations: R, W, Y, O, B, G, C
SET
ROOM
DIFF
Temperature
differential setting
Room temperature
Room temperature
setpoint
• Always turn off the thermostat before installing, removing, cleaning, or servicing; turn off the power at
the main power source by unscrewing fuse or switching off circuit breaker
• Do not switch to “Cool” if room temperature is below 50°F; this could damage your A/C system and
cause injury
• Do not install on voltages higher that 30 VAC
• All wiring must conform to local and national building and electrical codes and ordinances
• While cleaning, do not get soap directly on thermostat switches or LCD readout; only use a damp cloth
with a mild soap to wipe outside of thermostat cover
Specications
AS7812

3
Package Contents/Tools Required
Package includes: AS7812 non-programmable thermostat on base, thermostat cover, wiring labels,
screws and wall anchors, Installation, Operation and Application Guide.
Tools required for installation: Drill with 3/16” bit, hammer, screwdriver.
• The AS7812 thermostat is a digital, mercury-free, non-programmable, electronic thermostat
• Compatible with single-stage heating systems, heating/cooling systems, and heat pump systems; works
with gas, oil, or electric systems
• Compatible as a master thermostat in zoned system applications
• Freeze Protection Feature: Protects pipes from freezing! If the room temperature drops to 40°F, the
thermostat automatically turns on the heat; the thermostat must be in the Heat position
• Built-in Compressor Protection for Air Conditioners: To protect the A/C’s compressor, there is a 5-minute
delay between the system turning off and the A/C starting
• System Customization: Three available temperature differential settings
General Description

4
To Remove Existing Thermostat
ELECTRICAL SHOCK HAZARD – Turn off power at the main service panel by removing the fuse
or switching the appropriate circuit breaker to the OFF position before removing the existing
thermostat.
1. Turn off power to the heating and cooling system by removing the fuse or switching off the appropriate
circuit breaker.
2. Remove cover of old thermostat. This should expose the wires.
3. Label the existing wires with the enclosed wire labels before removing wires.
4. After labeling wires, remove wires from wire terminals.
5. Remove existing thermostat base from wall.
6. Refer to the following section for instructions on how to install this thermostat.
ELECTRICAL SHOCK HAZARD – Turn off power at the main service panel by removing the fuse
or switching the appropriate circuit breaker to the OFF position before removing the existing
thermostat.
IMPORTANT: Thermostat installation must conform to local and national building and electrical
codes and ordinances.
Note: Mount the thermostat about five feet above the floor. Do not mount the thermostat on an
outside wall, in direct sunlight, behind a door, or in an area affected by a vent or duct.
1. Turn off power to the heating and cooling system by removing the fuse or switching off the appropriate
circuit breaker. Move the Cool/OFF/Heat switch to OFF .
To Install Thermostat

5
To Install Thermostat (continued)
2. Move the FAN AUTO/ON switch to AUTO.
3. To remove cover, insert and twist a coin or screwdriver in the slots on the top of the thermostat.
4. Put thermostat base against the wall where you plan to mount it (Be sure wires will feed through the
wire opening in the base of the thermostat).
5. Mark the placement of the mounting holes.
6. Set thermostat base and cover away from working area.
7. Using a 3/16” drill bit, drill holes in the places you have marked for mounting.
8. Use a hammer to tap supplied anchors into mounting holes.
9. Align thermostat base with mounting holes and feed the control wires through wire opening.
10. Use supplied screws to mount thermostat base to wall.
CAUTION! : Be sure exposed portion of wires does not touch other wires.
11. Tighten screws on terminal block. Gently tug wire to be sure of proper connection. Double check that
each wire is connected to the proper terminal.
CAUTION! : Remove RH/RC jumper for 2 transformer system.
12. Set the fan jumper to electric or gas/oil, and heat pump jumper to NON-HP or HP.
13. Replace cover on thermostat by snapping it in place.
14. Turn on power to the system at the main service panel.

6
Replace the old labels with the enclosed new labels:
Replacing Wiring Labels
Old New Type
F, G G Fan control relay
O O Cool active reversing valve
B B Heat active reversing valve
Y, Y6 Y Cooling control
H, W, 4 W Heating control
C Transformer, common side
M, 4, RH, RS, R R Transformer, hot side
C Y or C
If the C terminal is the cooling control, connect to Y terminal; if
it is the common side of the transformer, connect to C terminal

7
4 or 5-Wire, Single Transformer
24 VAC T
H
E
R
M
O
S
T
A
T
R
C
Y
G
120 VAC
HOT
Transformer
Fan
Control
W
B
O
Heating
Control
(Optional)
Cooling
Control
AS7812 Wiring Diagrams
Heating and Cooling

8
4-Wire, Single Transformer
24 VAC T
H
E
R
M
O
S
T
A
T
R
C
Y
G
120 VAC
HOT
Transformer
Fan
Control
W
B
O
Heating
Control
3-Wire, Single Transformer
24 VAC T
H
E
R
M
O
S
T
A
T
R
C
Y
G
120 VAC
HOT
Transformer
W
B
O
Heating
Control
Heating Only

9
T
H
E
R
M
O
S
T
A
T
R
C
Y
G
W
B
O
T
H
E
R
M
O
S
T
A
T
R
C
Y
G
W
B
O
T
H
E
R
M
O
S
T
A
T
R
C
Y
G
W
B
O
24 VAC120 VAC
HOT
Transformer
24 VAC120 VAC
HOT
Transformer
24 VAC120 VAC
HOT
Transformer
Fan
Relay Fan Relay Fan Control
Cooling
Control
Compressor
Contactor
Reversing
Valve
Compressor
Contactor
Reversing
Valve
Heat Active
Reversing Valve
Cool Active
Reversing Valve
4-Wire
Single Transformer
Heat Pump Cooling Only
Note: Place jumper between “W” and “Y” terminals.
Place heat pump jumper to HP position.
Note: Millivolt system may require a
transformer and/or an isolation
relay to operate properly

10
CAUTION! : Do not switch system to cool if the temperature is below 50°F. This can damage the
air conditioning system and may cause personal injury.
Do not short jumper across terminals on the gas valve or at the system control to test installation.
Action: Set the Cool/Off/Heat switch to Cool. Press the button until the temperature
setting is 3°F below the room temperature.
Result: The A/C system and fan should turn on.
Action: Set the Cool/Off/Heat switch to Off.
Result: The A/C should turn off (There may be a fan delay).
Action: Set the Cool/Off/Heat switch to Heat. Press the button until the temperature
setting is 3°F above the room temperature.
Result: The heating system and fan should turn on (There may be a time delay depending on your
system).
Action: Set the Cool/Off/Heat switch to Off.
Result: The heating system should turn off (There may be a fan delay).
Action: Set the Fan Auto/On switch On.
Result: The blower fan should turn on.
Action: Set the Fan Auto/On switch to Auto.
Result: The blower fan should turn off.
If the above test was successful, you have a proper installation.
If not: Double check that wires are securely connected and are connected to the proper terminals. Consult
the troubleshooting section ( see Page 12 ).
A Quick Test

11
Setting the Room Temperature (Setpoint Temperature)
Step 1: Press one of the arrow buttons; the current temperature setting displays.
Step 2: Press the or arrow button until the desired temperature setting displays.
The new temperature setting is automatically saved. After 5 seconds, the display returns to showing the
current room temperature.
Setting a New Temperature Differential
The default temperature differential is 1°. When your room temperature varies by 1°F, the thermostat
turns your system on. If you notice your system turning on and off too frequently, increase the
temperature differential.
Step 1: Remove cover. Insert a coin or screwdriver in slot at the top if needed.
Step 2: Press the Reset button once (see diagrams on Page 1).
Step 3: When Diff01 displays, press the or arrow buttons to select the desired dirrerential setting.
Step 4: Replace the thermostat cover.
Starting the Thermostat
Step 1: Move the Fan Auto/On switch into the Auto position.
Step 2: Move the Cool/Off/Heat switch to Cool or Heat, depending on the season.
Operation

12
Symptom Remedy
The system isn’t turning on Check the wiring (see Installation, Page 7)
LCD is blank 24 VAC is at thermostat.
Thermostat is not properly controlling the fan Check that the Gas/Electric jumper setting matches your system (gas
or electric)
Thermostat is continuously turning on and off Increase the temperature differential (see Setting a New Temperature
Differential, Page 11)
Temperature displayed is not accurate Verify no heat producing objects are located near the thermostat.
Verify thermostat has adequate air flow to it.
Troubleshooting

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ONE-YEAR LIMITED WARRANTY
The Seller warrants its products against defects in material or workmanship for a period of one
(1) year from the date of manufacture. The liability of the Seller is limited, at its option, to repair,
replace or issue a non-case credit for the purchase prices of the goods which are provided to
be defective. The warranty and remedies set forth herein do not apply to any goods or parts
thereof which have been subjected to misuse including any use or application in violation of the
Seller’s instructions, neglect, tampering, improper storage, incorrect installation or servicing
not performed by the Seller. In order to permit the Seller to properly administer the warranty,
the Buyer shall: 1) Notify the Seller promptly of any claim, submitting date code information or
any other pertinent data as requested by the Seller. 2) Permit the Seller to inspect and test the
product claimed to be defective. Items claimed to be defective and are determined by Seller
to be non-defective are subject to a $30.00 per hour inspection fee. This warranty constitutes
the Seller’s sole liability hereunder and is in lieu of any other warranty expressed, implied or
statutory. Unless otherwise stated in writing, Seller makes no warranty that the goods depicted
or described herein are fit for any particular purpose.
LIA288
SPECIALISTS IN THE HVAC AND CONTROL INDUSTRIES
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