Robertshaw 300-206 User Manual

Your new Robertshaw thermostat has been designed to provide
accurate control and display of the room temperature. In addition, it
will also display all relevant information pertaining to your system.

The clearly marked buttons and informative display make it
extremely easy to understand and simple to use.

Please take a few moments to read the brief instructions and
familiarize yourself with the various functions in order to obtain
maximum benefit from this truly unique electronic control.

GENERAL INFORMATION

The thermostat normally displays room temperature, mode of
operation and whether cooling or heating is currently on. The
six buttons on the front of the unit allow complete control of
your equipment.

You may select different heating and cooling setpoints for the
system to maintain, e.g., 70° in heating and 75° in cooling.
Raising or lowering the setpoints in heating or cooling is as sim­ple as pushing a button. In addition, you may choose to display
the temperature in °F or °C.

The thermostat also allows you to select continuous fan operation
(useful when using an air cleaner) or have the fan come on with
the equipment.

BUTTON FUNCTIONS

Outdoor Press to display the outdoor temperature (optional)

Mode Press to select cool only, heat only, auto (cool and

heat) or off

Fan Press for continuous fan or auto fan

Day/Night Press to alternate between day and night

temperature setpoints

USER CONTROLS

MODE

Select the desired mode of operation by repeatedly pressing the
MODE button.

COOLING



Controls the cooling system only. Select the temperature you
want while in the cooling mode by pressing and holding the
 or  buttons. The word COOL and the temperature setting is
displayed for 5 seconds.

HEATING



Controls the heating system only. Select the temperature you
want while in the heating mode by pressing and holding the
 or  buttons. The word HEAT and the temperature setting is
displayed for 5 seconds.

FAN 

The fan will come on automatically when the system is operating.
To select continuous fan operation, press the FAN button and the
display will show



. This is recommended for electronic air

cleaners and continuous ventilation requirements.

OFF

To turn off the heating or cooling system, press the MODE button
until the word OFF appears on the LCD. Avoid using the OFF
mode during extremely cold weather to prevent damage to the
equipment from freezing.

USER CONTROLS (cont)

LIMITED OVERRIDE

When the keyboard is locked (switch #2 LOCKED), the user may
override the temperature setpoint for 1 hour by pressing either the
 or  button. The range of temperature override is ± 3° F or ±
3° C from the programmed daytime setpoint.

OUTDOOR BUTTON

If your thermostat has been installed with an electronic outdoor
remote sensor (Uni-Line Part #529), you may view the outdoor
temperature simply by pressing the OUTDOOR button. Upon
releasing the button, the thermostat will once again display the
indoor temperature. If the option is not connected, the thermostat
will display ---



.

DAY/NIGHT BUTTON 

When the thermostat is installed initially, the display will show the

symbol for your day temperature. By pressing the DAY/NIGHT

button you may select an alternate setback or night



temperature
(the thermostat will remember this setpoint). Simply press the
DAY/NIGHT button to alternate between temperature settings.

CELSIUS / FAHRENHEIT

Simultaneously press  and  to switch between Celsius (C) and
Fahrenheit (F) temperature display.

REMOTE SENSOR (OPTION)
RS1 – RS2 – RS+V

The thermostat is designed to accept the electronic remote sen­sor (Uni-Line Part #528) which will allow you to locate your ther­mostat in an area away from view.

CLOCK TERMINALS (OPTION) CLK1 – CLK2

Your thermostat is equipped with remote clock terminals. By
connecting a remote clock timer, the thermostat can be alternat­ed between the day and night (setback) temperature setpoints
automatically.

TEMPERATURE ACCURACY

Full temperature accuracy will only be realized after the thermo­stat has been installed and powered for at least one (1) hour.

POWER FAILURES

Your thermostat employs the latest in solid state electronic
technology.

One of the unique features of your thermostat is that no battery is
required to maintain your selected setpoints in the event of a
power loss as the memory is unaffected by power failures of
any duration.

When power is restored, the thermostat will continue operating as
if the power had never been off.

INSTALLATION INSTRUCTIONS

LOCATION

To ensure proper operation, the thermostat should be mounted on
an inside wall in a frequently occupied area of the building. In
addition, its position must be at least 18" (46cm) from any outside
wall, and approximately 5' (1.5m) above the floor in a location
with freely circulating air of an average temperature. You should
avoid the following locations:

– behind doors or in corners where freely circulating air is

unavailable;

– where direct sunlight or radiant heat from appliances might

affect control operation;
– on an outside wall;
– adjacent to, or in line with, conditioned air discharge grilles,

stairwells, or outside doors;
– where its operation may be affected by steam or water pipes or

warm air stacks in an adjacent partition space, or by an area

behind the thermostat which is not climate controlled;
– where its operation will be affected by the supply air of an adja-

cent climate control HVAC device; and
– near sources of electrical interference such as arcing relay

contacts

CAUTION

THIS DEVICE SHOULD BE INSTALLED BY A
QUALIFIED TECHNICIAN WITH DUE REGARD
FOR SAFETY, AS IMPROPER INSTALLATION
COULD RESULT IN A HAZARDOUS CONDITION

Operating Instructions

Digital Heating/Cooling Thermostat

Model 300-206

111-135B

REMOVING THE THERMOSTAT FROM THE SUBBASE

1. Insert a flat blade screwdriver or coin 1/8" into the
slot located in the bottom center of the thermostat
case and twist 1/4 turn. When you feel or hear a click,
grasp the case from the bottom two corners and separate from
the subbase. Some models require more force than others

when separating due to the number of terminals used.

2. Swing the thermostat out from the bottom.

3. Lift the thermostat up and off the subbase.

4. Place the rectangular opening in the subbase over the equip­ment control wires protruding from the wall and, using the sub­base as a template, mark the location of the two mounting
holes (exact vertical mounting is necessary only for appear­ance).

5. Use the supplied anchors and screws for mounting on drywall
or plaster; drill two 3/16" (5mm) diameter holes at the marked
locations; use a hammer to tap the nylon anchors in flush to
the wall surface and fasten subbase using the supplied screws.
(Do not over-tighten!)

6. Connect the wires from your system to the thermostat termi­nals. Carefully dress the wires so that any excess is pushed
back into the wall cavity or junction box. Ensure that the wires
are flush to the plastic subbase. The access hole should be
sealed or stuffed to prevent drafts from the wall affecting the
thermostat.

7. Before the thermostat is reinstalled on the subbase, install the
optional clock/timer, indoor remote sensor and outdoor remote
sensor, if used. Refer to the installation instructions supplied
with each option. Also check the position of the DIP switches
on the back of the thermostat.

REPLACING THE THERMO­STAT ON SUBBASE

1. Position the thermostat on the

hinged tabs at the top of the
subbase.

2. Gently swing the thermostat down

and press on the bottom
center until it snaps into place.

THERMOSTAT COVER LOCK

You may lock the cover down to pre­vent unauthorized access to the
thermostat by adding the plastic
lock (included in the installation bag).
Insert the plastic lock piece into the
bottom of the mounted base. The
ends of the lock piece fit snugly
under the lock pins extending from
the bottom of the mounted base.
The tab in the middle of the lock
piece extends down from the base.
To release the locking mechanism,
press the lock piece up and into the
base while gently prying open.

THERMISTOR MOUNTING INSTRUCTIONS

When placing the front
cover on the thermo­stat ensure the ther­mistor is not bent or
misaligned.
Ensure that the ther­mistor does not touch
the thermostat case.
The thermistor should
be placed horizontal to
the wall. Ensure the
thermistor is not
pushed upward
into the case.
The thermistor
should be aligned
so it is visible
between the ribs
on the bottom of
the subbase.

WIRING DIAGRAMS

SINGLE TRANSFORMER

TWO TRANSFORMERS

If the fault indicator is ON, the transformers are OUT OF PHASE.
Switch the secondary wires of one of the transformers (NOT
BOTH) and ensure the red light goes OFF.

Single RH/RC Wire

Separate RH and RC Wires

TERMINAL DESIGNATIONS

RH .............24 VAC from heating equipment transformer

W................Energizes the heating equipment with a call for heating

RC .............24 VAC from cooling equipment transformer

Y.................Energizes the cooling equipment with a call for cooling

G................Energizes the fan circuit

CLK1 .........Independent remote clock/timer optional for

CLK2 alternate setpoints

RS2............Use to connect remote temperature sensor(s).

RS1 Refer to the instructions included
RS+V with the sensors.

DIP SWITCH OPTIONS

Located on the back of the thermostat once the subbase is
removed.

Switch #1 – Allows for a 4-minute or 2-minute minimum on/off time.
Switch #2 – Allows for the keypad to be locked or unlocked.
Switch #3 – Allows for an immediate fan (electric heat) or a

natural delay for the fan (gas/oil heat).

SPECIFICATIONS

Rated Voltage 20-30 VAC, 24 nominal
Rated A.C. 0.08 Amps to 1.5 Amps continuous

Current per output with surges to 4 Amps max.
Control Heating: 38° to 88°F in 1° Steps

Range 5° to 30°C in 1° Steps

Cooling: 60° to 108°F in 1° Steps

16° to 40°C in 1° Steps

Thermostat
Measurement Range 28° to 124°F or 0° to 48°C

O.D.T. Displayed
Range -50° to 124°F or -48° to 48°C

Control Accuracy ±0.5°C at 20°C, ±1°F at 68°F
Minimum (between heating and cooling)

Deadband 2°F or 1°C

(Outside rear view with
backplate closed)

300-206

CLK1

CLK2

RS2

RS1

RS+V

Y

G

4 min. (on/off) 2 min. (on/off)

Unlocked Locked

1

2

RC

3

Gas

Electric

RH

W

Add jumper for

single transformer

CLK1
CLK2

RH

W

RC

Y
G

HEAT STAGE #1

COOL STAGE #1
FAN

W

Y

G

Transformer

24 VAC

Line
Voltage