Installation &
Operation Manual
SunStat® View
Programmable Thermostat
Model 500750 (-BB, -HB, -SB, -WB)
Items included
Unpack the thermostat control and make sure everything is in good condition.
Do not use a damaged control or part. The package comes with these items:
(1) Thermostat
(1) Thermostat Floor Sensor
(5) Wire Nuts (Marettes®)
(2) Mounting Screws
(1) Screwdriver
Tools and supplies needed
No. 2 Phillips screwdriver
Hole saw (if installing in an existing wall)
Wire strippers, wire cutters, and other electrical tools
Electrical wall box (plastic or metal)*
*A single-gang extra-deep box allows sufficient space to connect 1 or 2
heating mats or cables. For 3 heating mats or cables, a 4-inch square extradeep electrical box with a single-gang “mud ring” is necessary. Alternately,
a junction box may be installed to connect multiple heating mats or cables,
then run power supply wire from the junction box to the control electrical
box. See the Installation Instructions provided with the floor heating system
for more details.
Locating the Control
The SunStat View model 500750 is designed to operate either a 120 VAC or 240
VAC resistance floor heating system. It comes with an easy setup wizard, a typical
program ready to go, and a GFCI inside to meet safety needs.
Press anywhere on the display if the screen is blank. This wakes the display.
Read this Manual BEFORE using this equipment.
Failure to read and follow all safety and use
information can result in death, serious personal
injury, property damage, or damage to the
Keep this Manual for future reference.
Installation must be performed by qualified personnel, in accordance with
local codes and standards. A licensed electrician is recommended.
As with any electrical product, care should be taken to guard
against the potential risk of fire, electric shock, and injury to
persons. The following must be observed:
Wire all circuits as Class 1, Electric Light and Power Circuits.
Wire all circuits with insulation rated 600V minimum.
Mount this control only to a grounded metallic box or a nonmetallic box.
Use power supply wires suitable for at least 90°C.
High voltage – disconnect power supply before servicing.
The GFCI (ground-fault circuit interrupter) in this thermostat control does not
protect against shock if both bare conductors are touched at the same time.
• Do not exceed 15 amps on this thermostat control. Doing so will cause risk
of fire hazard and damage.
• Make sure the house power supply voltage matches the voltage rating of
the floor heating system. Do not apply 240 VAC to a 120 VAC rated system.
Connecting the wrong voltage may cause overheating and damage to the
system, the control, floor coverings, etc.
Local building or electrical codes may require modifications to the information
provided. You are required to consult the local building and electrical codes
prior to installation. If this information is not consistent with local building or
electrical codes, the local codes should be followed.
Find a suitable location for the control. Consider the following:
• It is designed for indoor dry location only.
• It may be placed on an insulated or uninsulated wall, preferably an interior
wall to avoid overheating from outside sun heat.
• Keep it away from all water sources such as sinks, showers, and bathtubs
as well as heat sources such as hot-water piping, heat ducting, wall-mount
lighting, and direct sunlight.
• Locate it at a suitable height, normally about 4-1/2’ to 5’ (1.4 m to 1.5 m)
from the floor.
Mounting the Electrical Box
• When mounting on an existing wall, cut the opening for the electrical box for
the control. To make it easier to pull the wiring, wait to install the electrical
box until after all wiring is drawn into this opening.
• When mounting on an open wall, secure the electrical box for the control to
the wall stud. Conduit from the electrical box to the floor is recommended
(check local codes for requirements) for additional protection. Install one
conduit for the floor sensor. Install another conduit for the floor heating
system power leads.
• Refer to the Installation Instructions supplied with the floor heating system
for additional installation details.
To prevent the risk of personal injury and/or death, make sure
power is not applied to the product until it is fully installed
and ready for final testing. All work must be done with power
turned off to the circuit being worked on.
House Wiring
Pull power supply wiring to the control location. Consider the following:
• Leave about 6 to 8 inches (15 to 20 cm) of wire for connections later.
• This wiring should be size 12 or 14 AWG following appropriate local code
• A qualified person should run a dedicated circuit from the main circuit
breaker panel to the control location. If a dedicated circuit is not possible, it
is acceptable to tap into an existing circuit. However, there must be enough
capacity to handle the load (amps) of the floor heating system being installed
and any possible appliance, such as a hair dryer or vacuum cleaner.
• Avoid circuits that have ballasted lighting, motors, exhaust fans, or hot tub
pumps due to possible interference.
• The circuit breaker should be rated 20 amps for total circuit loads up to 15
amps. A 15 amp circuit breaker may be used for total circuit loads up to 12 amps.
• A GFCI (ground-fault circuit interrupter) or AFCI (arc-fault circuit interrupter)
type circuit breaker may be used if desired, but is not necessary.
Floor Sensor
1. Test the Thermostat Floor Sensor included to make sure it has not been
damaged in handling. Use a digital multimeter set to the 20kΩ range. The
resistance varies according to the temperature sensed. These are approximate
values for reference:
Table 1 – Sensor resistances
55°F (13°C)
17 kΩ
65°F (18°C)
13 kΩ
75°F (24°C)
10 kΩ
85°F (29°C)
8 kΩ
2. Pull the floor sensor wire up the wall (or conduit) to the control location.
Consider the following:
• Leave about 6 to 8 inches (15 to 20 cm) of wire for connections later.
• The sensor wire may be cut shorter if desired, but do not cut it shorter until
the sensor is fully installed (see below). Re-strip the sensor wire ends 1/8" to
3/16" (3 mm to 4.5 mm) long. If the ends are stripped longer than this they
may short-circuit resulting in an Err2 code.
• If the sensor wire is not long enough to reach the control location, it may be
extended an additional 15 feet (4.5 m) using minimum 20 AWG 2-conductor
unshielded wire, or an additional 50 feet (15 m) using shielded wire. When
using shielded wire, the “shield” must be connected to the lower sensor
terminal, nearest to Bus A. A junction box may be required by local code for
the connection to this extension wire.
3. After the floor heating system is completely installed according to its
instructions, secure the thick sensor tip to the floor. Consider the following:
• It must be located halfway between heating wires and at least 1 foot into
the heating area.
• Use hot-glue to secure the sensor tip and wire in place.
• Do not cross over a heating wire.
• Avoid placing it in an area where heating wires are spaced further apart than
the rest of the floor, like a large gap between mats or cables.
• Avoid placing it in an area where a heat duct or recessed light will cause
improper measurements.
• Try to avoid locating it where future items such as a clothes hamper or similar
could trap heat and cause improper measurement.
Figure 1
Figure 2
Power Leads from Heating Mat or Cable
Pull the power lead wires from the floor heating system into the control location.
Excess power lead wire may be cut off, but leave about 6 to 8 inches (15 to 20
cm) of wire for connections.
Removing the Thermostat Front Module
1. Remove the Screw Cover at the bottom and loosen the screw.
2. Lift the Front Module away from the Power Module.
Front Module
Load 1
Line 1
Floor Sensor
Screw Cover
Line 2
Load 2
Cover Screw
Wiring Connections (see Figure 1 and 2)
Connect the wires as shown in the diagram. Consider the following:
• Gently tug on the wires to make sure they are secure. For added security, overwrap
the Wire Nut connections with electrical tape.
• If the electrical box is metal, a short length of wire must be secured to the electrical
box from the ground connection.
• When connecting the Floor Sensor to the Sensor terminals, it does not matter
which wire goes into which terminal.
• The Bus A and B terminals are used to communicate with a SunStat Relay II. Please
read and follow the instructions provided with the SunStat Relay II for further details.
Mounting the Thermostat
1. Make sure the power supply to the circuit is turned off at the circuit breaker.
2. Carefully press the wires back into the electrical box.
• DO NOT use the control to push wires in, as this may cause connections to
loosen and possible failure.
3. Use the Mounting Screws provided to secure to the electrical box and tighten
by hand.
• DO NOT over-tighten the screws causing the plastic to distort, as this may
cause improper function of the thermostat.
4. Press the Front Module onto the Power Module. Make sure both tabs at the
top are completely engaged.
• DO NOT install the Front Module with power applied on the Power Module,
as this may cause improper function of the thermostat.
5. Secure the screw at the bottom and replace the Screw Cover.
• DO NOT over-tighten the screw causing it to strip. Turn it until snug.
5. Pressing  will cancel the override and return to the Program Schedule.
Vacation Hold
To quickly override the Program Schedule to a low setpoint while on vacation, press
. Select “Vacation” and confirm. The display will show the vacation
setpoint temperature and “Vacation”. This temperature will hold until  is pressed.
Customizing the Program Schedule
1. Press Program .The schedule shown is set for the highlighted days shown
at the top of the display. This is a 7-day programmable thermostat, so each
day can have its own schedule.
2. Press
to browse through each day(s) schedule.
• Each day has 4 periods (WAKE, LEAVE, RETURN, SLEEP). A period is a certain
time that you wish the thermostat to begin heating at a certain setpoint
On/Off and Reset
Pressing will turn the thermostat on or off. This also resets the thermostat to
clear an error or GFCI fault. See “GFCI Testing” and “Troubleshooting”.
When first powered on, the thermostat begins a “startup wizard” to help the
user through basic setup.
1. Press “Begin”.
2. Select the language desired and press “Next”.
3. Select the format for the time and temperature and press “Next”.
4. Set the date and press “Next”.
5. Set the time and press “Next”.
6. The last display shows a short message. Press “Finish” and thermostat will
begin working automatically on a Pre-Programmed Schedule.
GFCI Testing
The GFCI (Ground Fault Circuit Interrupter) in this control must be tested when
installation is finished and once each month.
1. Make sure the control shows “Heating”. This may require temporarily increasing
the Setpoint temperature by pressing .
2. Press the GFCI TEST button. “GFCI TRIP” should be indicated on the control.
There will also be a click sound, indicating power has been removed from the
floor heating system. If either of these indications fail, turn off the thermostat
and replace it. Do not continue to use.
3. To reset the GFCI TRIP, press the button off and back on.
Adjusting the Temperature
Normally the thermostat will run automatically based on the settings in the
Program Schedule. However, these settings may be overridden temporarily or
for a specified period of time.
Temporary Adjustment
1. Press or to adjust the setpoint temperature. After a few seconds  will
show. This setpoint will be held until the next Program Schedule time.
2. Pressing  will cancel this override and return to the Program Schedule.
Hold a Setpoint Temperature
1. Press or to adjust the setpoint temperature.
2. For a few seconds the display will show H . Press to hold the setpoint
temperature instead of using the Program Schedule. The display will change
to show “Hold” and the current setting.
3. Press or to select the period of time to hold this temperature.
• Selecting “Continuous” will hold the temperature indefinitely.
• Selecting from 1 to 99 days will hold the temperature this number of days and
then return automatically to the schedule settings. This is useful when you are
away for a period of time and want to set it to a constant lower temperature,
saving energy during that time.
4. Press Done! to save the selection.
• To have the floor warm up to 80°F at 5:30 AM in the morning, set the WAKE
period to these values.
• To save energy and allow my floor to cool to 74°F after leaving at 7:15 AM,
set the LEAVE period to these values.
• To have the floor warm again to 80°F when returning home at 6:00 PM, set
the RETURN period to these values.
• Finally, to save energy overnight and cool the floor to 74°F after 10:00 PM,
set the SLEEP period accordingly.
• With the SmartStart feature turned on (see SmartStart below), the thermostat
will learn how long it takes the floor to reach 80°F and begin warming up a
little early, reaching approximately 80°F by the WAKE time 5:30 AM and again
at the RETURN time 6:00 PM. It will take a few days to learn.
3. Select the period to modify.
4. Adjust the Start time and Setpoint Temperature by pressing or .
• To clear a period, useful if you want to only raise and lower the temperature
once in a day, select the “Disable this period” option. The thermostat will skip
over this period in the schedule. There must be two periods in the schedule.
5. Press Done! to save.
Building a New Schedule
To build a completely new schedule, press New Schedule . Follow the onscreen
steps to select the days to schedule and modify each period to the desired
time and temperature. Pressing Next will take you to the remaining days to be
scheduled. Continue modifying the schedule for each day as needed. When all
days have been completed, press Done! to save these settings.
Changing Settings
1. Press Settings
2. Press
and select the se ng.
3. Press
to adjust the se ng.
4. Press Done! to save.
Table 2 - Settings
See the “Vacation Hold” section above.
Clean Screen
Allows the screen to be cleaned without function for 30 seconds.
IMPORTANT: Use a dry or damp soft cloth only to clean the screen.
Do not spray the screen directly and do not use harsh solvents or
abrasives as this may damage the screen and control.
Adjust the display brightness.
Set the time and date. This thermostat will automatically adjust
the time for daylight savings. If you want this ability turned off,
de-select the box “Adjust for Daylight Savings”.
The thermostat stores in memory the number of hours that it is
heating. This information may be useful in calculating the energy
used by the floor heating system. To reset these counters to zero,
press Clear and confirm.
Change the language shown.
Format of clock and temperature.
Floor Limit
Minimum and maximum allowable setpoint temperatures of
the floor sensor. This is useful when the floor covering cannot
exceed a certain temperature (84°F is common for many wood
or laminate products.
Not adjustable
Not adjustable
1 to 10
24 hours
7 days
30 days
All time
English, French,
12 or 24-hour
ᵒF or ᵒC
Table 2 - Settings continued
Floor Limit
Consult your floor covering manufacturer for recommended limits). maximum:
It is also useful to limit adjustment by users. And it is useful if the
99ᵒF (37ᵒC)
thermostat is being operated in Air Sensing mode (see Sensor
Default minimum:
Regulation below) but it is still desired to maintain a minimum floor
40ᵒF (4.5ᵒC)
temperature regardless of the air temperature.
Sensor Regulation
The thermostat is designed to operate best in Floor Sensing mode.
It is also possible to operate in Air Sensing mode with Floor Sensing
limitation. However, make sure to set a proper maximum Floor Limit
temperature (see Floor Limit above) to avoid overheating certain
floor coverings. Also note that internal heating in the thermostat
may affect the air sensor temperature reading.
Under special circumstances it may be desired to slightly adjust
the temperature that is displayed for the sensor. Normally this
is not recommended. The display will show the current sensor
temperature and the offset.
Allows the thermostat to learn and automatically determine the
best time to begin heating, reaching the setpoint temperature
at the scheduled time. For example, the schedule may have a
“WAKE” start time of 6:00AM to be 82ᵒF (27.8ᵒC) and SmartStart
may begin pre-heating at 5:30AM to reach 82ᵒF by 6:00AM. It will
take a few days to learn.
Factory Settings
Use with caution! This will clear all programming and settings to
factory condition. This is useful if there are problems or errors
which cannot be corrected.
Floor Sensor
Air Sensor
The following are common issues and solutions. A more complete list and more
solutions are on the manufacturer website.
Reset by turning thermostat off/on.
Reset by turning circuit breaker off/on.
No heat
Electrician: Check for loose wire connections at breaker and
junctions. Check for short-circuit to ground on heating system.
Allow sufficient time. Verify floor is insulated.
No heat HEATING Electrician: Check for correct resistance between heating system
power lead wires. Check for correct voltage supplied to heating
system. Check for correct amps drawn by heating system.
Reset circuit breaker.
Check contacts between Power Module and Front Module and
clean with alcohol wipe.
Electrician: Check for loose wire connections at circuit breaker and
junctions. Check for correct voltage between LINE1 and LINE2.
Check that the current time and schedule times are properly
set to AM or PM.
a t t h e HEATING On uninsulated concrete slab floors the SmartStart feature
may start heating very early. You may turn this feature off
if not desired.
No heat
Check Floor Limit values (see Table 3).
95°F or
Electrician: Check to make sure only one Floor Sensor is attached.
No heat
Error Codes: An error code may display due to a power glitch or other false issue.
1. Try clearing the Error code once by turning the thermostat off, resetting the
circuit breaker, and then turning the thermostat back on.
2. Check the contacts between Power Base and Front Module for dirt or damage.
Turn the circuit breaker off and remove the Front Module. Are the contacts bent
or dirty? Try gently cleaning them with a rubbing alcohol wipe. Dirt or oil may
have contaminated them during installation. In most locations this step may be
performed without an electrician since there is no power available.
3. Check that the Mounting Screws are not too tight causing distortion. Turn
the circuit breaker off and remove the Front Module. Back the screws out
until the Power Base is just snug to the wall.
4. Check that both clips at the top are engaged and that the screw at the
bottom is snug.
If these actions and the following do not resolve the issue, turn off the
circuit breaker and contact the manufacturer for direction. Do not continue
using the system to prevent further risk of damage, fire, or electrical shock.
No heat
No heat
Floor Sensor wires may be crossed.
Electrician: Check if the Floor Sensor wires crossed and shortcircuited. Check Floor Sensor resistance (see Table 1 in the
Installation section above).
No heat
Floor Sensor wires may not be connected.
Check Floor Sensor connections and mounting screws as
stated above.
Electrician: Check if Floor Sensor is attached. If not, attach
and reset the circuit breaker.
No heat
Err4 or
Err5 and
No heat
Internal temperature limit may be exceeded.
Check if sunlight or other heat source is causing added heat
to thermostat.
Electrician: Check if load exceeds 15 amps.
No heat
Contacts or internal connections may be faulty.
Check connections and mounting screws as stated above.
Reset circuit breaker.
No heat
Internal device error.
Default: ON
If problems arise with the thermostat, please consult this troubleshooting
guide. If not qualified to perform electrical work, it is highly recommended
a qualified, licensed electrician be hired. Any electrical troubleshooting work
should be performed with the power removed from the circuit, unless otherwise
noted. Although this troubleshooting guide is provided to assist with problems
experienced with a system, results are never guaranteed. Watts Radiant does
not assume any liability or responsibility for damage or injury that may occur
from using this guide. If problems with the system persist, call the manufacturer.
Insert the ends of the floor sensor wire into the terminals marked “SENSOR”
and snug the screws. It does not matter which wire goes into which terminal.
Floor Sensor may be wrong type.
Electrician: Check floor sensor resistance. See Table 1 in the
Installation section above.
±9ᵒF (±5ᵒC)
Internal air sensor may be faulty.
Change setting to Floor Sensing mode (see Table 3 above).
Power Supply
120 / 240 VAC, 50/60 Hz
Maximum Load
15 A, resistive
Maximum Power
1800 W at 120 VAC / 3600 W at 240 VAC
Class A (5 mA trip nominal)
Display Range
32ᵒF to 99ᵒF (0ᵒC to 37ᵒC)
Setting Range
40ᵒF to 99ᵒF (4ᵒC to 37ᵒC)
± 0.9ᵒF (0.5ᵒC)
Indoor dry location only
Storage Temperature
0ᵒF to 120ᵒF (-17ᵒC to 49ᵒC)
Floor Sensor
Thermistor, 10k NTC type, double insulated, Class2
Programming retained indefinitely. Current time/day will
need reset if power is lost more than 30 minutes.
ETL Listing
Control No. 3037530. Conforms to UL 873, UL 943, CSA C22.2
No. 24, CSA/CAN C22.2 No. 144.
Limited Warranty
Watts Radiant warrants this control (the product) to be free from defect in
material and workmanship for a period of (3) years from the date of original
purchase from authorized dealers. During this period, Watts Radiant will replace
the product or refund the original cost of the product at Watts Radiant’s option,
without charge, if the product is proven defective in normal use. Please return
the control to your distributor to begin the warranty process.
This limited warranty does not cover shipping costs. Nor does it cover a product
subjected to misuse or accidental damage. This warranty does not cover the
cost of installation, diagnosis, removal or reinstallation, or any material costs
or loss of use.
This limited warranty is in lieu of all other warranties, obligations, or liabilities
expressed or implied by the company. In no event shall Watts Radiant be liable for
consequential or incidental damages resulting from installation of this product.
Some states or provinces do not allow limitations on how long an implied
warranty lasts, or the exclusion or limitation of incidental or consequential
damages, so the above exclusions or limitations may not apply to you. This
warranty gives you specific legal rights and you may also have other rights that
vary from state to state.
WARNING: This product contains chemicals known to the State of California to cause cancer
and birth defects or other reproductive harm. For more information:
A Watts Water Technologies Company
IOM-WR-SS-View 1408
USA: Springfield, MO • Tel. (800) 276-2419 •
Fax: (417) 864-8161 •
© 2014 Watts Radiant
Download PDF