REMOVING THE OLD THERMOSTAT:
1. Switch OFF the electricity to the heating/cooling equipment; then
proceed with the following:
FRONT PANEL ITEMS
Complete, Easy To Read
SYSTEM MODE SWITCH:
INSTALLATION AND OPERATING INSTRUCTIONS
2. Remove the front cover from your old thermostat. Most will
simply pull straight off, while others may be fastened by screws.
3. Take note of the letters printed near each of the wire terminals.
Attach adhesive labels (enclosed) to each wire for identification by
their terminal letter, not the color of the wire.
4. Make sure the wires do not fall back inside the wall. Remove and
label each wire one at a time, and do not allow the wires to touch
each other or any parts of the thermostat.
The MODE switch has 4 positions: EMER, HEAT, OFF, and COOL. In
the summer, set the switch to COOL to control cooling. In the
winter, set the mode switch to HEAT to control heating; set the mode
switch to EMER to control auxiliary heating only (if equipped). In
the EMER position, the heat pump compressor is disabled. When set
to OFF mode, the heating and cooling system will remain off.
BATTERY POWERED, NON-PROGRAMMABLE
DIGITAL HEAT PUMP THERMOSTAT
FAN MODE SWITCH:
The FAN switch has 2 positions: AUTO and ON. In the AUTO
position, the operation of the blower fan is determined only by the
on/off cycling of the heating and cooling system. In the ON position,
the system's blower fan will be commanded ON continuously at all
times, even when the system mode switch is in the OFF position.
5. Loosen all screws on the old thermostat base, and remove it from
LUX PRODUCTS CORPORATION
MOUNTING THE NEW THERMOSTAT:
1. Strip insulation leaving approximately 3/8 in. (10mm) of bare wire
on the ends, and clean off any corrosion present.
2. Fill the wall opening with non-combustible insulation to prevent
drafts from affecting the thermostat while in use.
3. Pull your new thermostat apart by applying pressure to the thumb
tab on the bottom edge of the unit, while pulling the front and
back halves apart from the bottom edge of the thermostat.
Mt. Laurel, New Jersey 08054, USA
WARNING: Use Energizer® or DURACELL® Alkaline Batteries Only.
Energizer® is a registered trademark of Eveready Battery Company, Inc.
DURACELL® is a registered trademark of The Gillette Company, Inc.
There are two push buttons to the right of the unit's display screen.
These are used to adjust the set point temperature.
I M P O R T A N T !
Please read all instructions carefully before beginning installation
and save for future reference. Before removing any wiring from
your existing thermostat, the wires must be labeled with their
terminal designations. Ignore the color of the wires since they
may not comply with any standard.
NOTE: If you are mounting the base to a soft material like
plasterboard, or if you are using the old mounting holes, the
screws may not hold. Drill a 3/16-in (4.8mm) hole at each
screw location, and insert the plastic anchors provided.
While in HEAT, COOL, or EMER modes, a single press on either the
UP or DOWN button causes the word “SET” to appear on the screen,
and the set temperature value on the screen to start flashing. When
flashing, the set temperature can be altered by pressing either the
UP or DOWN button once per degree of change, or by holding either
button for at least two seconds to automatically increment the set
temperature quickly in the associated direction.
Thank you for your confidence in our product. You should become
fully acquainted with this thermostat before installing it for usage.
Follow the installation procedures carefully, and one step at a time.
This will save you time and minimize the chance of damaging either
the thermostat or the systems that it controls. These instructions
may contain information beyond that required for your particular
installation. Please save these instructions for future reference.
4. Route the wires through the large hole adjacent to the terminal
block, and hold the base plate against the wall. Position the base
for best appearance, and to hide any marks from an old
thermostat. Attach the base to the wall with the two screws
Based upon the relationship of the set temperature to the displayed
ambient room temperature, the thermostat will engage the first stage
of either heating or cooling, if a temperature demand is present.
If there is a large thermal demand present which is greater than the
first stage of heating can accommodate, then a second stage of
heating (W2) will be activated, showing the word “AUX” on the
display screen. There is approximately a 4-minute delay that is
imposed between the activation of the first stage of heating, and the
second stage of heating.
• The DHP2120 thermostat can be used with most 24 volt: single-
stage heat pumps, and 2 heat / 1 cool heat pump systems.
** Complete heating or cooling system wiring can be found in the
WIRE IDENTIFICATION AND WIRING SCHEMATICS section of this
instruction sheet. The schematics show system components for
brand new installations or for un-referenced wires.
• This thermostat cannot be used to control: conventional heating
and cooling systems, 3-wire zone valves, or 120/240 volt (line
voltage) heating or cooling systems. Ask your dealer for other
LUX® thermostats to control those systems.
CONNECTING THE WIRES:
Pressing either set temperature button will illuminate the display.
The light will remain on for approximately 12 seconds. While the
light is illuminated, pressing any of the 2 push buttons will cause the
light to remain on for approximately 12 more seconds.
5. Clean bare wire ends must be inserted in between the
black clamp and the brass terminal as shown here.
6. Securely tighten all electrical terminal screws
(even unused ones).
MINIMUM RUN/OFF TIME:
Quick & Easy
This is determined by the thermostat, and controls the minimum
length of time that the thermostat must remain with Heat or Cool
either On or Off, before it will automatically switch to the alternate
On or Off state. This feature prevents rapid or short cycling, and
also provides compressor protection. The duration of this delay is
fixed at 5 minutes between on or off load changes.
If batteries are presently installed, remove them from the thermostat
before proceeding with changing any of the options listed below. A
table similar to this one shown here is printed on the thermostat's
ADJUSTABLE TEMPERATURE STOPS:
Large Easy to
There are two independent set temperature stops: a maximum heat
set temperature, and a minimum cool set temperature. Each of these
temperature stops is user adjustable in one-degree increments. The
heat temperature stop prevents the set temperature from being
adjusted higher than the heat temperature stop value. The cool
temperature stop prevents the set temperature from being adjusted
lower than the cool temperature stop value.
JP2 (B / O)
To set the heat and cool temperature stops, place the system mode
switch in the OFF position. Press and hold the UP key while sliding
the mode switch from either OFF to HEAT (to adjust the maximum
heat set temperature), or from OFF to COOL (to adjust the minimum
cool set temperature). “Ht Lim” or “Cl Lim” will be displayed on the
LCD screen while you are setting the heat or cool limits respectively.
While in the adjustment mode for each of the temperature stops, use
the UP and DOWN buttons to adjust the limit value, just as you
would for adjusting the set temperature under normal operation.
There are 2 option jumpers located inside the thermostat on the
circuit board. These settings can be changed from their default
values by removing its corresponding black shorting cap and
installing the cap so that it is positioned on the adjacent pair of
metal pins. A change to either of the option jumpers will not be
recognized unless the thermostat has been without battery power for
at least 2 minutes, and then power is restored again. Each of these
jumpers changes a different setup option. The choices for these
options are listed in a table printed on the circuit board, and are also
printed adjacent to each individual setting jumper.
Battery Powered Only
Easy To Install
F / C Selectable Temperature Display
Fixed 5 Minute Minimum Run /
Off Time For Compressor Protection
Adjustable Temperature Stops
Set Temperature Range 45°F to 90°F
Clean, Attractive Design
Large, Easy To Read Display with
NOTE: If no buttons are pressed for 4 seconds, the thermostat will
accept the limit value that was on the screen, and return to normal
operating mode, for the current mode switch position. Once,
complete, you should return to the adjustment mode again for both
heat and cool to confirm your desired settings for both temperature
modes have been accepted.
PLEASE READ ALL INSTRUCTIONS CAREFULLY BEFORE BEGINNING
JP1 - FAHRENHEIT OR CELSIUS DISPLAY FORMAT:
This setting controls whether the temperature is
shown in degrees °F or °C on the LCD display
C A U T I O N :
BATTERIES AND MAINTENANCE
This thermostat is protected against normal static electric
discharges. However, in extremely dry weather you should
touch a grounded metal object before touching the thermostat
to minimize the risk of causing damage to the unit.
The batteries in the thermostat should be replaced AT LEAST once
per year, or sooner if the “LO BAT” battery symbol appears in the
lower right portion of the display screen.
JP2 - [B] OR [O] TERMINAL USAGE OPTION:
This setting determines how the thermostat will use
the shared B/O terminal connection on the back
plate. Select the “B” option to have the B/O
terminal powered while in heat mode, and un-
powered while in cool and off modes. Select the
“O” position to have the B/O terminal powered while
in cool mode, and un-powered while in heat and off
modes. If you are not sure which way to set this
option, consult the manufacturer of your heat pump
To replace the batteries in the thermostat, remove the thermostat’s
body from the wiring base plate attached to the wall by pressing the
thumb latch at the bottom center of the unit and swinging the front
body out towards you, up and away from the base. Remove the used
batteries from the battery tray and discard appropriately.
• #1 Phillips screwdriver (small - medium)
• Drill with 3/16-in. (4.8mm) drill bit
• Wire stripper/cutter
Install two new Energizer® or DURACELL®, “AA” size Alkaline
batteries into the battery tray. Observe the polarity markings shown
in the battery compartment to ensure proper installation. When
finished, hang the top of the unit by the tabs at the top corners of
the base, and then snap the bottom of the unit into place. Do not
use unnecessary force. If the body does not snap into place easily,
remove the body, re-hang it from the tabs at the top and try again.
C A U T I O N :
Turn off electricity to the appliance before
installing or servicing the thermostat or any part
of the system. Do not turn the electricity back
on until the work is completed.
Once all optional jumper settings have been performed as described
in the previous section, ensure that the thermostat has been without
battery power for at least 2 minutes for the change to be recognized.
Now install new batteries into the thermostat. When installing
batteries, use two new Energizer® or DURACELL® “AA” size alkaline
batteries only. Ensure that the batteries are installed in the proper
direction as per the markings shown in the battery tray.
Your thermostat is a precision instrument. Please handle it with
Do not short (jumper) across the electric terminals on your
heating or cooling equipment to test the system. This may
damage the thermostat and void your warranty.
All wiring must conform to all applicable local codes and
If you have any problems installing or using this thermostat, please
carefully and thoroughly review the instruction manual. If you
require assistance, please contact our Technical Assistance
COMPLETING THE INSTALLATION
Department at 856-234-8803 during regular business hours between
8:00AM and 4:30PM Eastern Standard Time, Monday through Friday.
You can also receive technical assistance online anytime day or night
the most common technical questions, and also permits you to email
your questions to our technical support staff at your convenience.
Install your new thermostat onto its base. To do this, start with the
bottom tilted out towards you at first, and line up the two holes in
the top of the thermostat with the two hooks on the top of the back
plate. Slowly pivot the bottom of the thermostat towards the back
plate and push firmly on the bottom half of the thermostat until it is
securely latched to the back plate. If the two thermostat halves do
not mate together easily, remove and try again. Do not attempt to
force them together if they do not appear aligned properly.
This thermostat is limited to a maximum of 1.5 amps, total
current; higher current may cause damage to the thermostat.
On replacement installations, mount the new thermostat in place of
the old one unless the conditions listed below suggest otherwise.
On new installations, follow the guidelines listed below.
1. Locate the thermostat on an inside wall, at about 5 ft. (1.5m)
above the floor, and in a room that is used often.
2. Do not install it where there are unusual heating conditions, such
as: direct sunlight, near a lamp, television, radiator, register,
fireplace, on a wall opposite a stove, or that carries hot water
3. Do not locate in unusual cooling conditions, such as: on a wall
separating an unheated room, or in a draft from a stairwell, door,
4. Do not locate where air circulation is poor, such as: in a corner or
alcove, or behind an open door.
Limited Warranty: If this unit fails because of defects in materials or
workmanship within three years of the date of original purchase, LUX
will, at its option, repair or replace it. This warranty does not cover
damage by accident, misuse, or failure to follow installation
instructions. Implied warranties are limited in duration to three
years from the date of original purchase. Some states do not allow
limitations on how long an implied warranty lasts, so the above
limitation may not apply to you. Please return malfunctioning or
defective units to the location from which the purchase was made,
along with proof of purchase. Please refer to "Technical
NOTE: Before use, remove the plastic film (if present) that is
protecting the LCD display screen.
Turn the electrical power back ON to both your heating and/or
cooling systems. Verify that both systems are operating properly.
When set to a high temperature, the heating system should provide
warm air after a short time in Heat Mode. Likewise, the cooling
system should provide cool air after a short time when set to a low
temperature in Cool Mode. Usually, sound from the heater and/or
cooling system units can be heard while either is running. Your
installation is now complete.
ASSISTANCE" before returning thermostat. Purchaser assumes all
risks and liability for incidental and consequential damage resulting
from installation and use of this unit. Some states do not allow the
exclusion of incidental or consequential damages, so the above
exclusion may not apply to you. This warranty gives you specific
legal rights and you may also have other rights which vary from
state to state. Applicable in the U.S.A. and Canada only.
5. Do not locate in a damp area. This can lead to corrosion that may
shorten thermostat life.
6. Do not install the unit until all construction work and painting has
2 0 0 8 L U X P R O D U C T S C O R P O R AT I O N . A L L R I G H T S R E S E R V E D