Bestech BT21NP User manual

WARNING
Important Safety Information
1
BT11NP
Single Stage Heat / Cool
Conventional and Heat Pump
• Always turn off power to the air conditioning or heating system prior to
installing, removing, cleaning or servicing thermostat.
• This thermostat is a dual power thermostat and either requires 24 Volts AC
Power or two (2) properly installed “AA” alkaline batteries for normal
operation and control of the heating or cooling system. Refer to “Low Battery
Detection and Replacement” section for more information.
• This thermostat should only be used as described in this manual. Any other
use is not recommended and will void the warranty.
Specifications
Installation
Testing Your New Thermostat
Programming User Settings
Temperature Adjustment
Additional Operation
Features
Battery Replacement
Troubleshooting
Wiring Diagrams
1
2
3
4
5
6
7
8
9
1
Specifications
• Model BT21NP: Compatibility with low voltage multi-stage gas, oil or electric
heating or cooling systems, including multi-stage heat pumps; can also be
used on 250 to 750 millivolt heating only systems.
• Terminations, Model BT11NP: Rc, Rh, B, O, Y, W, G, C
• Terminations, Model BT21NP: R, O, B, C, Y1, E/W1, G, W2
Specifications
cont.
Installation
2
Before Installing, Programming or Operating,
PLEASE READ ALL INSTRUCTIONS
BT21NP
Multi-Stage 2 Heat / 1 Cool
Conventional and Heat Pump
• Electrical Rating: 24 Volt AC (18-30 Volt AC)
1 amp maximum load per terminal
2 amp total maximum load (all terminals) (Model BT11NP)
3 amp total maximum load (all terminals) (Model BT21NP)
• Control Range: 45˚ - 90˚ F (7˚- 32˚ C)
• Accuracy: +/- 1˚ F (+/- .5˚ C)
• AC Power: 18-30 Volt AC
• DC Power: 3.0 Volt DC (2 AA Alkaline batteries included)
• Model BT11NP: Compatibility with low voltage single stage gas, oil or
electric heating or cooling systems, including single stage heat pumps; can
also be used on 250 to 750 millivolt heating only systems.
NOTE–These thermostats are designed for use with 24 Volt-AC low voltage gas,
oil or electric heating or cooling systems, including heat pumps and can also be
used on 250mv to 750mv millivolt heating only systems. Do not use this
thermostat on applications with voltages above 30 Volts AC.
1
Replacing Existing Thermostat
Old Terminal from
Existing Thermostat
New Terminal for
New Thermostat
(BT11NP)
New Terminal for
New Thermostat
(BT21NP)
Terminal
Description
V or Rc Rc Cooling
Transformer
M, 4, Rh, or R Rh Heating
Transformer
R, V-VR or VR-R R 24 VAC
B B B Reversing Valve
(Heating)
O O O Reversing Valve
(Cooling)
Y, Y1 or M Y Y1 Cooling or
Compressor for
HP System
E, H, W, W1 or 4 W E/W1 1st Stage Heat
or Emergency Heat
G or F G G Fan Control
C, X or B C C 24 VAC Common
W2 W2 2nd Stage Heat
Most thermostats have three parts:
• The cover, which may snap or hinge over the existing thermostat.
• The electronics or body, which controls the existing system.
• The sub-base, where the wires attach through the wall to the existing system.
1. Always turn off power to the air conditioning or heating system prior to
removing existing thermostat.
2. Carefully remove the cover and electronics body from the old thermostat sub-base.
Depending on the brand, these parts may pull off or need to be unscrewed. The
old sub-base should remain wired and on the wall until steps 4 and 5.
3. Label every old wire with the letter of the connection to which the wire is
attached. Example letters are R, M, Y etc. Depending on the brand of the old
thermostat, your letters may be different.
4. After labeling the old wires, loosen each connection and remove them from old
sub-base. Secure the wires to prevent them from slipping into the hole in the wall.
5. Remove the old sub-base from the wall, again being careful that the wires do
not slip into the hole in the wall.
6. Use the chart below to determine the new thermostat connections. As an
example, if the old thermostat had a G connection, it goes to G on the new
thermostat. Note the chart includes information for BesTechTM BT11NP and
BT21NP thermostats. Be sure to use the correct column for the new thermostat.
Non-Programmable Thermostats

23
WARNING!
Read BEFORE Testing
Installation
2cont.
Installation
2cont.
Testing Your New Thermostat
3
• Do not short (or jumper) across terminals on the gas valve or at the heating or
cooling system control board to test the thermostat installation. This could
damage the thermostat and void the warranty.
• Do not select COOL mode if the outside temperature is below 50˚ F (10˚ C).
This could damage the controlled cooling system and cause personal injury.
• This thermostat includes an automatic compressor protection feature to
avoid potential damage to the cooling system from short cycling. This
thermostat automatically provides a 5-minute delay after turning off the
cooling or heating system output to protect the compressor.
NOTE: Test your thermostat prior to programming any user settings. Pressing
the RESET button will erase any user entries previously programmed and return
them to their default values.
1. Place the system switch in the HEAT position.
2. Press the button on the keypad until the set point temperature setting is a
minimum of 3 degrees higher than the current room temperature. The heating
system should start within several seconds. The fan may not turn on
immediately due to the heating system built-in fan delay.
3. Place the system switch in the OFF position. The heating system should stop
within several seconds with conventional heating or cooling systems. On heat
pump systems you must wait 5 minutes for the automatic compressor short
cycle protection period to expire, or press the RESET button to bypass this
feature for initial testing purposes. Pressing the RESET button will erase any
user program settings.
4. Place the system switch in the COOL position.
5. Press the button on the keypad until the set point temperature is a minimum
of 3 degrees lower than the current room temperature.
6. The cooling system should start within several seconds. Place the system
switch in the OFF position. The cooling system should stop within a few seconds.
7. Place the fan switch in the ON position. The system blower should start.
8. Place the fan switch in the AUTO position. The system blower should stop.
NOTE: If the thermostat was powered (batteries installed) prior to accomplishing
steps 14 through 16, you will need to reset the thermostat to register thermostat
switch configurations prior to programming any user settings. Gently press
the RESET button on the front of the thermostat using a paperclip or a small
pencil tip.
NOTE – MODEL BT21NP: If the thermostat is
configured for a conventional system and the system
switch is in the EMER position, the unit will still
function in a conventional 2 stage HEAT mode, but
the display will flash NO AUX SET.
Installing New Thermostat
NOTE: If installing this thermostat in a new installation, locate the thermostat
4 to 5 feet above the floor in accordance with applicable building codes. Install the
thermostat in a location that provides good airflow characteristics and avoid areas
behind doors, near corners, air vents, direct sunlight or heat generating devices.
Installation in these areas could impact thermostat performance. Wiring must
conform to all building codes and ordinances as required by local and national
code authorities having jurisdiction.
1. Always turn off power to the air conditioning or heating system prior to
installing thermostat.
2. Place system switch on front of thermostat to the OFF position.
3. Place fan control switch on front of thermostat to the AUTO position.
4. Remove front of thermostat body from sub-base by pressing release latch on
bottom of thermostat.
5. Place the thermostat sub-base against wall in the desired thermostat location.
6. Guide thermostat wires through hole in sub-base and continue to hold
against wall.
7. Mark placement of mounting holes as appropriate and drill using a 3/16" drill bit.
8. Gently tap supplied plastic anchors into the holes in the wall.
9. Place the thermostat sub-base against the wall in the desired location, making
sure the mounting holes are aligned and the thermostat wires are inserted
through the opening in sub-base.
10. Fasten sub-base to wall using supplied screws.
11. Connect wires to quick wiring terminal block using the new terminal designations.
Refer to Wiring Diagram in section 9 of this manual for assistance.
12. Make sure all of the wire connections are secure and are not touching
any other terminal to prevent electrical shorts and potential damage to
the thermostat.
13. Turn the front thermostat body over, exposing the rear view of the circuit board.
14. Locate the internal ˚F / ˚C switch on the circuit board. Using your fingers, flip
the switch toward the preferred temperature ˚F / ˚C scale.
15. Locate the internal fan option switch, HG (Gas) / HE (Elec) on the circuit board.
This switch controls the heating system fan delay. Select gas for gas or oil fired
systems. This will allow the furnace to run for a few seconds before initiating
the fan. Select electric for electric heat systems that require the fan to come on
immediately. Using your fingers, flip the switch toward HG (Gas) or HE (Elec).
NOTE: (BT21NP) For heat pump systems, the fan option switch should be set
according to the second stage heating system type.
16. Locate the internal NORM / HP switch on the circuit board. This switch
configures the thermostat for conventional (NORM) heating and cooling systems
or heat pump (HP) systems. Using your fingers, gently flip the switch toward
NORM or HP.
17. Attach front body of thermostat to sub-base of thermostat, being careful to
align the terminal pins on the front body with the terminal block on the sub-base.
18. Open front thermostat door and open battery compartment door.
19. Install two new "AA" alkaline batteries. Locate the positive (+) ends of the
batteries and match them with the positive (+) terminals located in the battery
compartment. Close battery compartment.
20. Restore system power so you can test installation.

4
Default Thermostat Settings Setting Second Stage Differential (BT21NP Only)
Setting Temperature Differentials
5
Review Set Temperature
cont.
Programming User Settings
4
The default settings for the first and second stage differentials are compatible
with most systems and applications. This is normally set at time of installation and
usually does not require any modification under normal operating conditions. If you
feel that your system is turning on too often, simply follow the instructions below.
NOTE: The first and second stage differential settings are the same for both the
heating and cooling systems.
Setting First Stage Differential
The default setting is 0.5˚ F (0.25˚ C). The room temperature must change .5˚ F
(0.25˚ C) from the set point temperature before the thermostat will initiate the
system in heating or cooling.
1. In normal operating mode, press and hold the and
buttons at the same time for 3 seconds. LCD display will
show "SET D1 x˚", where "x" equals the ˚F / ˚C differential
setting. This is the current first stage differential setting.
2. Press the or buttons to set the first stage differential
to your desired setting of .5˚, 1˚, or 2˚ F (.2, .5˚ or 1.0˚ C).
NOTE–MODEL BT11NP: Once you have finished setting the first stage
differential, you can wait 5 seconds and the thermostat will return to the normal
operating mode. Or you can press both the and buttons at the same time to
return to normal operating mode.
NOTE–MODEL BT21NP: If you do not wish to change the second stage
differential, you can wait 5 seconds and the thermostat will automatically return
to the normal operating mode. Otherwise, you can press both the and
buttons at the same time to return to normal operating mode.
Programming User Settings
The default setting is 2˚ F (1.0˚ C). The room temperature
must change 2˚ F (1.0˚ C) in addition to the first stage
differential setting before the thermostat will initiate the
second stage of the system in heating.
3. Press and hold the and buttons at the same time
again and the LCD display will show "SET D2 x˚", where "x" equals the ˚F / ˚C
differential setting. This is the current second stage differential setting.
4. Press the or buttons to set the second stage differential to your desired
setting of 2˚, 3˚, 4˚, 5˚ or 6˚ F (1˚, 1.5˚, 2˚, 2.5˚ or 3˚ C).
NOTE – MODEL BT21NP: Once you have finished setting the second stage
differential, you can wait 5 seconds and the thermostat will return to the normal
operating mode. Or you can press both the and buttons at the same time to
return to normal operating mode.
NOTE: To erase all user program settings, gently press the RESET button using
a paper clip or a small pencil tip. This will return all thermostat settings to their
default values, erasing all program settings entered by the user.
Temperature Adjustment
1. Press and hold the button. The current set point
temperature will be displayed in place of the current
room temperature, and the indicator SET will be displayed.
2. The display will return to normal operating mode when
the button is released. The SET indicator will
turn off, indicating that the current temperature shown in the display is the
room temperature.
Changing Set Temperature
1. Press and hold the button for more than 1 second.
The entire display will flash once and the SET indicator
will be flashing. Release the button and press
the or button again to adjust the set temperature.
2. The display will return to normal operating mode after 5
seconds, or you can press both the and buttons at
the same time to return to normal operating mode.
3. The SET indicator will turn off in the display, indicating
that the current temperature shown in the display is the
room temperature.
NOTE: This thermostat has separate heating and cooling set points, which
can be reviewed or changed by selecting either HEAT or COOL with the
system switch.
4
5
Function Status After Reset
Operation Mode Normal Operating Mode
Room Temperature 70˚ F (21.0˚ C), to be
renewed within 5 seconds
Set Point Temperature According to system switch
Heat or Off: 62˚ F (17.0˚ C)
Emergency Heat (BT21NP) only):
62˚ F (17.0˚ C)
Cool: 85˚ F (29.0˚ C)
Temperature Scale ˚F or ˚C dependent on switch setting
Low Battery Warning Off, to be renewed within 5 seconds.
Off if 24V is present
1st Stage Differential 0.5˚ F (0.25˚C)
2nd Stage Differential 2˚ F (1.0˚ C)
Short Cycle Protection Timer Reset
Output Relays Off

6
Compressor Protection Feature
Low Battery Detection and Replacement
This thermostat includes an automatic compressor protection feature to avoid
potential damage to the system from short cycling. This thermostat automatically
provides a 5-minute delay after turning off the cooling system output to protect
the compressor. This protection is also present in the heat mode of operation on
heat pump systems to protect the compressor.
NOTE: The installer can bypass the compressor protection feature by pressing
the RESET button. This will erase all user program settings, returning all settings
to their default values. This should only be used during installation for testing
purposes or to reset a thermostat to regain normal operation.
Additional Operation Features
6
This dual power thermostat requires two (2) new, properly
installed “AA” Alkaline batteries to provide proper thermostat
power when 24 volt AC power fails or is not connected to
the thermostat. When the batteries start to become too weak
to provide proper operation, the thermostat will begin to
display a 3 Stage Low Battery Indicator.
Low Battery Stage Battery Indicator Duration Action
Stage 1 Solid 0-30 Days Replace Batteries
as Soon as Possible.
Stage 2 Flashes Every 31-60 Days Replace Batteries
2 Seconds Immediately to
Provide Proper
Operation.
Stage 3 Flashes Every 61-90 Days Replace Batteries
1 Second Urgently to
Provide Proper
Operation.
The 3 Stage Low Battery Indicator is provided to inform the user when the
batteries require immediate attention. We recommend replacing the
batteries as soon as the low battery indicator appears. If the batteries are
not replaced after the low battery indicator first appears, the thermostat
may not provide proper heating or cooling system operation.
Even if the low battery indicator does not appear, the batteries should be replaced
at least once a year, or if you plan on leaving the premises for over a month.
This dual power thermostat can be powered from 24 volts AC or battery power.
To determine if 24 volt AC power is connected to the thermostat, refer to the
installation and wiring diagram section. If you cannot determine how this
thermostat is powered, call a professional service technician to determine the
type of installation and the proper operation of your system.
Non-Volatile Memory
In the event of a power failure, the Non-Volatile Memory feature allows all settings
to be recovered, eliminating the need to reset temperature and differential settings.
When AC power is restored after an outage or batteries are reinserted, all settings
are retrieved from memory and reinstated.
7
Troubleshooting
8
Additional Operation Features
cont.
6
COOL
Battery Replacement
7
Status Indicators
HEAT: This will turn on whenever the system switch
is in the HEAT mode. “HEAT” will flash when the
heating system is running.
COOL: This will turn on whenever the system switch
is in the cool mode. “COOL” will flash when the
cooling systems is running.
AUX (Model BT21NP Only):This will turn on when the
auxiliary (second stage) of heating is active. The auxiliary
stage of heating is usually the least economical stage of
heat and typically runs when the first stage of heat
cannot keep up with the temperature demand.
NOTE: AUX is also displayed when the system switch is in
the Emergency (EMER) Mode.
Replacing the Batteries
1. Open front cover and locate the battery compartment door.
2. Gently remove the two "AA" alkaline batteries located in the battery compartment.
3. Install two new "AA" alkaline batteries into battery compartment. Make sure to
match the positive (+) ends of the batteries with the positive (+) terminals
located in the battery compartment.
4. Close battery compartment. The low battery indicator should not appear
in the display.
Symptom: Thermostat does not turn on heating or cooling system.
Potential Solution: Check to see if OFF is shown in display. This indicates that the
system is turned off at the thermostat. Move system selector switch to HEAT or COOL
position. After the compressor short cycle protection 5-minute period expires, the
system should start.
Compressor protection feature may be in effect due to compressor short cycle
conditions. See Section 6.
Heating or cooling system may be malfunctioning. Call a professional service technician
immediately to verify system operation.
Symptom: Thermostat turns on heating instead of cooling, or cooling instead of heating.
Potential Solution: Check thermostat wiring to make sure the heating and cooling
stages are connected to the correct terminals on the wiring block. See Section 9.
Symptom: Thermostat turns heating or cooling system on too often or not often enough.
Potential Solution: Increase or decrease temperature differential settings as appropriate
to provide the desired performance level. See Section 4.
Symptom: Low battery indicator is blinking in thermostat display.
Potential Solution: Replace batteries immediately to maintain proper system operation.
See Section 7.

89
cont.
Symptom: OFF is shown in thermostat display and heating or
cooling system will not start.
Potential Solution: This indicates that the system is turned off
at the thermostat. The thermostat must be in HEAT or COOL
mode of operation to control the heating or cooling system.
Move the system selector switch to the HEAT or COOL position.
Symptom: Thermostat display is blank.
Potential Solution: It is possible that AC power is not present at the thermostat, and/or
the batteries are drained. Check fuse, circuit breaker and thermostat wiring as
appropriate to verify AC power is available. Replace batteries before reprogramming
thermostat. See Section 7. If AC power is present, call a professional service technician
to verify thermostat and system performance.
Symptom: HI is shown in the thermostat display.
Potential Solution: The temperature sensed by the thermostat
is higher than the 99˚ F (37˚ C) upper limit of the thermostat’s
display range. The display will return to normal after the sensed
temperature lowers within the 40˚ to 99˚ F (4˚ to 37˚ C) display
range. Turn on the cooling system or use other methods to lower
the temperature accordingly.
This condition could occur from the system being turned off during an exceptionally
warm period or upon installation when the thermostat has been stored for a long
period of time in a warm vehicle or location prior to being installed.
Symptom: NO AUX SET is shown in the thermostat display.
(model BT21NP only)
Potential Solution: The thermostat (model BT21NP)
only) is configured for a conventional system, and the system
switch is in the EM HEAT position. The unit will still function in
a conventional 2 stage HEAT mode, but the display will flash
NO AUX SET. Move the system switch to the HEAT position.
Symptom: LO is shown in the thermostat display.
Potential Solution: The temperature sensed by the thermostat
is lower than the 40˚ F (4˚ C) lower limit of the thermostat’s
display range. The display will return to normal after the sensed
temperature rises within the 40˚ to 99˚ F (4˚ to 37˚ C) display
range. Turn on the heating system to raise the temperature as
needed for comfort within the room.
This condition could occur from the system being turned off during a cold weather
period or upon installation when the thermostat has been stored for a long period of
time in a cold vehicle or location prior to being installed. The thermostat should be
allowed to warm up prior to installation to allow proper heating control once installed.
Symptom: Cannot program a set point temperature higher than 90˚ F (32˚ C).
Potential Solution: This is above the normal thermostat temperature setting range of
45˚ to 90˚ F (7˚ to 32˚ C).
Symptom: Fan continues to run whether the system is on or off.
Potential Solution: Check that the fan control switch is in the AUTO position. This will
allow the fan to run only when the heating or cooling system is turned on and running.
Check thermostat wiring to make sure that the fan control wiring is connected to the
correct terminals on the wiring block. See Section 9.
Troubleshooting
8
Symptom: The room is too warm or too cold.
Potential Solution: See Section 5. Review current set point and change as necessary.
Symptom: HEAT or COOL is flashing, but the system is not running.
Potential Solution: The thermostat is telling the heating or cooling system to run, but
the system is not responding. You may need to call your local heating and air
conditioning contractor.
Wiring Diagrams
Rc Rh G
Factory Installed
Jumper
MODEL BT11NP: Single Stage Conventional Systems (Single Transformer)
WYB O
Heat
Control
Fan
Control
Cool
Control
NOTES: 1. Transformer common not required for battery-only operation of
thermostat. 2. For heating or cooling only system, ignore opposite connection.
3. For 2-wire 24 Volt AC or 250 mV - 750 mV millivolt heating systems, ignore
cooling connection and fan control.
C
Transformer Common
(See NOTE 1)
NOTE: Transformer common not required for battery-only operation of thermostat.
9
Troubleshooting
8
24 VAC
Neutral
120 VAC
Hot
24 VAC
120 VAC
Neutral
Hot
Cooling
Heating
120 VAC
Neutral
Hot
24 VAC
C
Rc Rh B
Remove
Factory Installed
Jumper
MODEL BT11NP: Single Stage Conventional Systems (Dual Transformer)
O Y W G
Heat
Control
Cool
Control Fan Control
Transformer Common
(See NOTE)

MODEL BT11NP: Single Stage Heat Pump System
Compressor
Control
cont.
Wiring Diagrams
9
Transformer Common
(See NOTE 1)
cont.
Wiring Diagrams
9
R O
Reversing Valve
(Active in Cooling
- See NOTE 3)
B Y1 G W2
Transformer Common
(See NOTE 1)
1st Stage
Compressor
Contact
Emergency
Heat Control
2nd Stage
Heat Control
Fan Control
24 VAC
See NOTE 2
MODEL BT21NP: Multi-Stage Heat Pump Systems
NOTES: 1. Transformer common not required for battery-only operation of
thermostat. 2. Jumper is required to use Auxiliary Heat for both Second Stage and
Emergency Heat on units without separate Emergency Heat and Auxiliary Heat terminals.
3. For units requiring reversing valve to be energized during heating, connect reversing
valve to B terminal. For units requiring reversing valve to be energized during cooling,
connect reversing valve to O terminal.
Reversing Valve
(Active in Heating
- See NOTE 3)
C E/W1
(See NOTE)
Transformer Common
R Y1 E/W1 W2GO B C
1st Stage
Compressor
Control
1st Stage
Heat Control
Fan
Control
2nd Stage
Heat Control
24 VAC
Neutral
120 VAC
Hot
MODEL BT21NP: Conventional Systems (Single Transformer)
NOTE: Transformer common not required for battery-only operation of thermostat.
10 11
B
Reversing
Valve (Active in
Cooling - See
NOTE 2)
O W C
24 VAC
Reversing
Valve (Active in
Heating - See
NOTE 2)
Y G
Rc Rh
Factory Installed
Jumper
Fan
Control
Neutral
120 VAC
Hot
Neutral
120 VAC
Hot
NOTES: 1. Transformer common not required for battery-only operation of
thermostat. 2. For units requiring reversing valve to be energized during heating,
connect reversing valve to B terminal. For units requiring reversing valve to be
energized during cooling, connect reversing valve to O terminal.

©2010 BesTech • All Rights Reserved • www.bestechparts.com
U.S. Patent 7,438,469 and other patents pending. Made in China • BTNP-100-002
This warranty gives you specific legal rights and you may also have other rights that vary from
state to state or province to province. Answers to any questions regarding our limited warranty
may be obtained by writing our corporate offices.
For warranty service, please visit your nearest Baker Distribution facility.
Call us toll-free: 866-268-5599 (U.S.) • 630-844-1968 (Outside the U.S.)
Baker Distributing warrants each new BesTech thermostat against any defects that are due to
faulty material or workmanship. This warranty and our liability does not apply to batteries, nor
does it include damage to merchandise or the thermostat resulting from accident, alteration,
neglect, misuse, improper installation or any other failure to follow BesTech installation and
operating instructions. This limited warranty applies for the duration of the warranty period
from the original date of purchase by a professional service technician.
Baker Distributing agrees to repair or replace at its option any BesTech thermostat under
warranty provided it is returned postage prepaid to our warranty facility in a padded carton
within the warranty period, with proof of the original date of purchase and a brief description
of the malfunction. This limited warranty does not include the cost of removal or
re-installation.
2 Year
Limited
Warranty
Non-Programmable Thermostats
Store this
Booklet for
Future
Reference