Robertshaw RS5220C Owner's Manual

1

Thank you for purchasing a Robertshaw RS5220C programmable
thermostat. This user’s manual will guide you through the setup of the
RS5220 two stage thermostat. The thermostat should already be
mounted and correctly wired. The default settings will enable the
thermostat to operate efficiently. Before making any changes to the
schedule read the section on Default Settings.

Features

• Pop-Up Wizard

• Automatic changeover

• Circulating Fan

• Worry-Free memory retention

• Easy change battery

• Large back lit display

• Filter change reminder

• Low battery indicator

• Fahrenheit and Celsius displays

• EnergyStar™ compliant

• Dual power

• Adjustable 1st stage temperature differential: 0.5 °F to 3.0 °F (0.5 °C
to 1.5 °C)

• Accuracy within ±1 °F

• Universal staging on multi-stage units

• Automatic heating shutdown if temperature exceeds 99 °F (37 °C)

• Keypad security lockout

• 4 events per day for heating and cooling

• 5-2 day scheduling

• User settable Hi and Lo temperature limits

• Vacation setpoint override

RS5220C

352-00059-001 Rev B

USERS MANUAL

2

Application

The Robertshaw RS5220C thermostat is designed to control gas, electric,
oil, heat pump, and millivolt heating and electric cooling systems. The
RS5220C is a two stage thermostat.

The RS5220C thermostats use 5-2 programming. This means the 5
weekdays will operate on one schedule and the 2 weekend days will
operate on a second schedule

IMPORTANT SAFETY INFORMATION
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.

• This is a 24V AC low-voltage thermostat. Do not install on voltages
higher than 30V AC.

• 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.

• This thermostat is configured with automatic compressor protection
to prevent damage because of short cycling or extended power
outages. Short cycle protection provides a delay between heating
and cooling cycles on heat pumps.

Detailed mounting and wiring instructions are explained in the
Installation Manual.

Refer to the Pop-Up Wizard section in the installation manual for a
complete list of factory defaults and contractor settings.

Providing Power to the Thermostat

For wiring diagrams refer to the Installation Manual.
The thermostats will operate using 24V AC or two AA batteries. When

the two AA batteries are installed the thermostat will continue to run if
the 24V AC fails.

3

Installing or Changing the Batteries

To remove the battery compartment gently
squeeze the ribbed edges on both sides.

The battery compartment will pull down from
the thermostat body and will detach. Install
two AA batteries following the polarity as
shown inside the compartment. Place
compartment back into the thermostat.

When the batteries are low the thermostat
will enter a low battery mode.

Low battery mode has two levels.

• LEVEL 1: The low battery icon will be displayed. The
thermostat will continue to operate. Replace the
batteries as soon as possible

• LEVEL 2: The low battery icon will flash. If 24V AC is
present the thermostat will continue to operate if
the batteries are discharged or removed. If 24V AC
is not present the thermostat runs on batteries only
and THE SYSTEM WILL NOT OPERATE. Replace
batteries immediately.

Replace batteries if leaving thermostat unattended for more than
30 days.

The clock will continue to run for 10 minutes when the batteries
are removed.

Display Description

The thermostat display will show information that is being used during
operation or programming. This illustration shows all of the display’s
possibilities with an explanation.

1

2

4

14

13

12

1. Event Names (used for editing schedule).

2. Day is displayed on Idle screen. Also used to display day ranges
when editing the schedule (e.g., SAT SUN for weekend).

3. Used with clock to display hold duration (e.g., FOR 2h).

4. On when running a schedule.

5. Used with setpoint.

6. Used along with clock for service reminders (e.g., CHECK HP).

7. Used for time, current setpoint, and some configuration data (e.g.,
filter hours).

8. HVAC mode and status. Icons blink when active. A is for Auto, 2 is
for second stage, E is for emergency.

9. Indicates when security is active.

10. Low battery indicator.

11. Displayed when in vacation hold.

12. Used for ambient temperature and configuration data (e.g., first
stage differential, F or C, etc.).

13. Fan status (rotates when active).

14. Fan mode selected by pressing FAN button.

11

9

10

3

5

6

7

8

4

Schedule Settings – Defaults

This thermostat is preprogrammed with a schedule that is recommended
by EnergyStar™. The schedule is designed to lower energy costs
year-round.

The default schedule settings are:

Time Cooling °F Heating °F
Morn 6:00 am 78 70
Day 8:00 am 85 62
Eve 6:00 pm 78 70
Nite 10:00 pm 82 62

User Settings – Defaults

During any program changes the display returns back to the operating
display if a button has not been pushed in 10 seconds.

The temperature scale is set to Fahrenheit.
Night light is on.
The first stage differential is 1 °F.
The second stage differential is 2 °F.
The second stage delay is 20 minutes.
Auto changeover is enabled.
Auto changeover deadband is 3 °F.
Filter reminder length is off.
Temperature offset is 0 degrees.
The HI heat limit is 90 °F (32 °C).
The LO cool limit is 45 °F (7 °C)
The vacation temperature settings are set at: heating 60°F, cooling 85 °F.
The operation mode is OFF.
The fan setting is Auto.
The keypad has no password protection.
Refer to the pop up wizard section in the installation manual for a

complete list of factory defaults and contractor settings.

Emergency Heat

Your system may include Emergency Heat. The RS5220C thermostats
have an emergency heat capability for multi stage heat pump systems.
To determine if your system is capable of using emergency heat contact

your contractor. Use the button to enter the EMER mode. An E will
be displayed with the Heat symbol. This mode is used to bypass the
heat pump when it needs servicing or when it cannot keep up with the
heat demand.

5

Auto Changeover

Auto changeover is the ability of the thermostat to switch automatically
between heating settings and cooling settings. This is useful in Spring
and Fall when the days are warm and the nights are cool. In heat mode
if the room continues to warm beyond a set threshold the thermostat
switches to the cool mode and the associated cooling settings. The
reverse is also true.

As the room temperature changes, the thermostat will call for heating or
cooling as needed. To prevent the heating and cooling systems from
overriding each other, an auto changeover deadband is used.

The deadband is the minimum temperature swing before changing from
heating to cooling or vice versa. The larger the deadband the more the
room temperature will vary.

Operating the Thermostat

Any setting can be changed when it is flashing by pushing or
If a button is not pushed for 10 seconds the thermostat returns

to operation.
The following buttons can be accessed from the front panel.

START/STOP SCHEDULE: Switches between running a schedule and
manual (permanent override). Cancels a temporary override.

EDIT SCHEDULE: Use this button to start editing the schedule. Push
repeatedly to move through the selections.

VACATION: Used to set a temporary setpoint for a number of days.
SET TIME: Sequences through the hour, minute and day.
LIGHT BAR: Turns on the display back light for 10 seconds.
FAN: Turns fan to AUTOMATIC, CIRCULATE or ON.
UP ARROW: Raises the setpoint or increases flashing item.
DOWN ARROW: Lowers the setpoint or decreases flashing item.
HEAT/COOL: Toggles through OFF, HEATING, COOLING, and AUTO.

If configured as HP then emergency heat is also displayed.

6

Setting Time and Day

To adjust the time and day settings press the SET TIME button. The hour
will flash. If a button is not pushed in 10 seconds the thermostat returns
to operation. To change the settings:

1. Use the and buttons to change the flashing number.

2. Press the SET TIME button to move through hour, minutes and day
of week.

3. Make changes as needed. They will be saved automatically.

NOTE: The thermostat will not correct for Daylight Saving Time.

The thermostat will now function properly using the default schedule.

Changing the Schedule Settings

This thermostat can operate using a single setpoint by overriding the
schedules. If you will be using this thermostat for single setpoint
operation skip to Overriding the Schedule.

The chart below represents one day’s programming schedule. To make
programming your thermostat quicker and easier, recreate the table
for each day of the week on a separate piece of paper, and refer to it
while programming.

Press START/STOP SCHEDULE at any time to exit and save your settings.
Push START/STOP SCHEDULE. The display will show a day flashing at

the top. If a button is not pushed in 30 seconds the thermostat returns
to normal operation.

Use the or to change the hour of the start time if desired.
Push EDIT SCHEDULE to move to minutes.

Use the or to change the minutes of the start time if desired.
Push EDIT SCHEDULE to move to the heat or cool temperature setting.

Use the or to change the temperature setpoint.
Push EDIT SCHEDULE to move to the other setpoint.

Use or to change the temperature setpoint.
NOTE: Pressing will switch between cooling and heating setpoints.

Pressing Set Time button will switch back to the event time.

NOTE: The heating and cooling setpoints CANNOT be entered as

crossed. That is, the cooling setpoint CANNOT BE lower than
the heating setpoint.

Push EDIT SCHEDULE and repeat this process for the remaining
three settings.

Time Cool Heat
Morning
Day
Evening
Nite

7

After the weekend schedule is complete, the display will show the
weekend schedule. Continue the same steps to program the four
weekend setting

When finished press START/STOP SCHEDULE or wait 30 seconds and
the thermostat will return to operation.

Changing the User Settings

When and are pressed at the same time the thermostat will
display the current settings in order.

To change any setting:

When the setting is visible and flashing press the or
arrows to adjust the number on the screen.

To exit the changes and save:

Press START/STOP SCHEDULE. The thermostat will return
to operation.

SCAL = Scale in °F (Fahrenheit) or °C (Celsius).

CLOC = Set clock to 12 or 24 hour format.

LITE = Display backlight always on ”y” or off ”n”. Also called the

nightlight feature. If the thermostat has been wired with 24V AC
(R and C terminals) then this feature will be displayed and the
setting can be changed.

8

DIFF = The differential keeps the thermostat from turning on for small

changes in temperature. When in Fahrenheit the range is 0.5 to

3.0 Degrees. In Celsius the range is 0.5 to 1.5 Degrees. The
differential is factory set at 1.0 °F (0.5 °C). This means that
whenever the room temperature is more than 1 °F (0.5 °C)
different from the set temperature the system will turn on. If the
system is turning on too often, increase the differential setting.
Note that a larger differential will mean the room temperature
changes more before the system turns on.

DIF2 = Second Stage Differential = Operates with the first stage to

control a second heating/cooling system. This number will be
added to the first stage differential (See: Two Stage Systems).
If the first stage is running too often lower the settings. This will
turn the second stage on to help the first stage. If both stages
are coming on too often then increase this setting to delay the
second stage.

DLY2 = Second Stage Delay = This timer starts when the first stage turns

on. It resets when the first stage turns off. If this timer runs out
the second stage will turn on (See Two Stage Systems).

Auto changeover enable = Makes the auto changeover mode available.

When chosen, the thermostat can automatically switch between
heating and cooling. Note that the High and Low setpoint limits
are not enforced in auto changeover mode.

9

DEDB = Deadband for auto changeover = the number of degrees that the

room temperature can move away from the active setpoint until
heating or cooling is called for. The larger the deadband the
more the room temperature will vary. This can be from heat to
cool or cool to heat.

HI = High Heat Limit = This is the highest allowed heating setpoint. The

user will not be allowed to set a schedule setpoint or override
temperature higher than this value.
NOTE: High Heat Limit is not enforced in auto changover mode.

LO = Low Cool Limit = This is the lowest allowed cooling setpoint. The

user will not be allowed to set a schedule setpoint or override
temperature lower than this value.
NOTE: Low Cool Limit is not enforced in auto changover mode.

VAC HEAT = Vacation Heat Setpoint = This is the temperature setpoint

for the heating system when a vacation override has been
made active.

VAC COOL = Vacation Cool Setpoint = This is the temperature setpoint

for the cooling system when a vacation override has been
made active.

10

CHECK = Timer to remind the home owner to maintain the filter. Default

setting is off. The timer runs when the system is on. It can be
set at 0 (OFF) or up to 9900 hours. When the time expires

CHECK FLTR is displayed. Press the and buttons to
restart the filter timer.

CYCL = Cycle Timer allows a compressor to rest between cycles. Can be

set from 0 to 5 minutes in 1 min increments.

WARNING: A wrong short cycle setting can
damage your equipment. This should only
be changed by a trained HVAC professional.

CAL = Calibration offset. Changes the displayed temperature from the

actual temperature by +3 to -3 degrees in one degree increments.
Increasing the offset by +2 will cause the thermostat to display a
temperature that is 2 degrees higher than the actual room
temperature

Creating a Password – Protect the Settings

The buttons on the front of the thermostat can be locked with a password.
To create a password:

1. Press the and buttons at the same time and hold them in
for 5 seconds.
You will be asked for a 4 digit password.

2. Each digit is set using the and buttons. Press the to
move to the next digit. Press to move back.

3. The password is saved after 5 seconds.

All of the front buttons are now locked out until the password is entered.
Pressing any button will cause to flash.

To unlock the buttons:

1. Push and hold the and buttons for 5 seconds until the
request for password is displayed.