YoLink Thermostat (Heat Pump Compatible)

YS4003-UC
Installation & User Guide
Rev 1.1
Revised: 05/09/2023
Copyright © 2023 YoSmart Inc. All rights reserved

TABLE OF CONTENTS

A. Welcome!
B. Before You Begin
C. What's in the Box?
D. Install the YoLink App
E. Add Your Thermostat to the App
F. Prepare for Installation
G. Installation
H. Get to Know Your Thermostat
I. Set the Cooling or Heating Setpoint
J. Navigating the Menu System
K. Schedules: Editing & Copying
L. Y & Aux Config
M. Date & Time
N. Temperature Settings
O. Display & Sound
P. Factory Reset
Q. App Functions: Device Screen
R. App Functions: Device Details Screen
S. Automation
T. Voice Assistants & Integrations
U. Troubleshooting
V. CE Mark Warning
W. FCC Statement
X. 1-Year Warranty
Y. Warnings
Z. Contact Us & Customer Support

User Guide Conventions
 To assure your satisfaction with your purchase, please read this user guide we have prepared just for you. The following icons are used to convey specific types of information:

	Very important information (can save you time!)
	Good to know info but may not apply to you
	Mostly unimportant (it’s ok to breeze past it!)

A. Welcome!

Thank you for purchasing YoLink products! We appreciate you trusting YoLink for your smart home & automation needs. Your 100% satisfaction is our goal. If you experience any problems with your installation, with our products or if you have any questions that this manual does not answer, please contact us right away. See the Contact Us section for more info.

Thank you!

Eric Vanzo
Customer Experience Manager

B. Before You Begin

Visit our YoLink Thermostat support page on our website, for the latest installation guides, additional resources, information and videos by visiting:

https://shop.yosmart.com/pages/thermostat-product-support

Or by scanning the QR code:

Download the most current version of the user guide by scanning the QR code:

This thermostat works with common single-stage 24-volt systems such as forced air, hydronic, heat pump, oil, gas, and electric. It will not work with millivolt systems, such as a gas fireplace, or with 120/240 volt systems such as baseboard electric heat.

Before you begin installation, please note, the Thermostat requires a C (Common) wire. It will not function without a C wire. If the thermostat location does not have a C wire, a new C wire, or a C wire adapter, must be installed. Please contact us for additional information and technical support on this topic.

This thermostat works with common single-
stage 24-volt systems such as forced air, hydronic, heat pump, oil, gas, and electric. It will not work with millivolt systems, such as a gas fireplace, or with 120/240 volt systems such as baseboard electric heat.

Your Thermostat connects to the internet via a YoLink hub (SpeakerHub or the original YoLink Hub), and it does not connect directly to your WiFi or local network. In order for remote access to the device from the app, and for full functionality, a hub is required.
This guide assumes the YoLink app has been installed on your smartphone, and a YoLink hub is installed and online (or your location, apartment, condo, etcetera, is already served by a YoLink wireless network).

Need Help?

Please contact us via the Contact Us section of this user guide, for assistance, before returning your Thermostat.

C. What's in the Box?

Thermostat	Quick Start Guide
Mounting Plate(“Back Plate”)	Screws (2)Drywall Anchors (2)
Wire Labels

D. Install the YoLink App

1. If you are new to YoLink, please install the app on your phone or tablet, if you have not already. Otherwise, please proceed to part F.

   Scan the appropriate QR code below or find the “YoLink app” on the appropriate app store.

   Apple phone/tablet iOS 9.0 or higher	Android phone/tablet 4.4 or higher

   Open the app and tap Sign up for an account. You will be required to provide a username and a password. Follow the instructions, to set up a new account

   Allow notifications, if prompted.

   If you encounter an error message attempting to create an account, disconnect your phone from WiFi, and try again, connected only to the cellular network

   Retain your username and password in a secure location

2. You will immediately receive an email from no-reply@yosmart.com with some helpful information. Please mark the yosmart.com domain as safe, to ensure you receive important messages in the future.
3. Log in to the app using your new username and password. The app opens to the Favorite screen, as shown. This is where your favorite devices will be shown. You can organize your devices by room, in the Rooms screen, later.
4. Tap Add Device (if shown) or tap the scanner icon

   QR code scanner icon

E. Add Your Thermostat to the App

1. Approve access to the camera, if requested. A viewfinder will be shown on the app.
2. Hold the phone over the QR code (on the Dimmer Switch “Remove After Registering” decal, as well as on the rear of the Dimmer Switch) so that the code appears in the viewfinder. If successful, the Add Device screen will be displayed
3. Refer to Figure 1 on the next page. You can edit the name of the Dimmer Switch, and assign it to a room, if desired. Tap the Favorite heart icon to add this device to your Favorites screen. Tap Bind device
4. If successful, close the Device Bound pop-up message by tapping Close
5. Tap Done as shown in Figure 2.

   Figure 1	Figure 2

   If this is your first YoLink system, please visit our product support area at yosmart.com for an introduction to the app, and for tutorials, videos, and other support resources.

6. Ensure your YoLink Hub or SpeakerHub is setup and online before proceeding to the next step.

F. Prepare for Installation

The following items may be required for the installation of your Thermostat:

Drill with Drill Bits	Multimeter
Medium Phillips Screwdriver	Small Slotted Screwdriver
Level	Pencil
Alternative Mounting Hardware

G. Installation

Please Note: This installation manual assumes the Thermostat is replacing an existing thermostat. For new installations please disregard references to the existing thermostat, etc.

1. Refer to the chart above, match up your thermostat wires with their matching screw terminal on the Thermostat terminal strip.
   

   THERMOSTAT TERMINAL	TYPICAL WIRE DESIGNATIONS	FUNCTION	REMARKS
   Y	Y	NON-HEAT PUMP: PRIMARY COOLING	TYPICALLY YELLOW
   		HEAT PUMP: COMPRESSOR ON/OFF CONTROL
   G	G	FAN RELAY	TYPICALLY GREEN
   W	W, O/B	NON-HEAT PUMP: PRIMARY HEATING	TYPICALLY WHITE, ORG, BRN
   	W, O/B	HEAT PUMP: HEAT OR COOL MODE	ACCORDING TO O/B SETTING
   AUX	AUX, or E	EMERGENCY HEAT
   C	C or COM	24VAC COMMON	TYPICALLY CYAN, SEE NOTE #1
   R	R, RC, RH	24VAC POWER	TYPICALLY RED
   	Y1,Y2	MULTI-SPEED OR SECOND-STAGE COOL	SEE NOTE #2
   	W2	SECOND STAGE HEAT	SEE NOTE #2
   	OAT	OUTSIDE AIR TEMPERATURE	SEE NOTE #3
   	SRTN, OAT RETURN	OUTSIDE AIR TEMPERATURE	SEE NOTE #3

   Note #1: Confirm the presence of a C wire, or one labeled COM or COMMON. The Thermostat will not function without a C wire (or C wire adapter, as previously noted).

   Note #2: The Thermostat is not compatible with multi-speed cooling, two or second-stage cooling or heating

   Note #3: The Thermostat does not use an outdoor temperature sensor. This is an optional feature used for heat pump lockout, based on outside temperature. As there is no automatic lockout with the Thermostat. To avoid possible compressor damage, do not run the air conditioner if outside temperatures are below 50°F (10°C).

   If your existing thermostat has additional wires that do not appear to correspond with any of these wire designations, please contact us.

   CAUTION:  To prevent personal injury and damage to property, always remove power to the thermostat by turning off the HVAC equipment at the circuit breaker panel, prior to performing any steps related to connecting or changing the thermostat wiring!

2. Turn off power, as required, to ensure there are no energized wires at the thermostat location.
3. Before making any changes to the thermostat wiring, it is important to identify the individual wires and their functions using the supplied labels (or masking tape, etc.) label each wire with the same identifier that is on the existing thermostat ("C", "R" etcetera). It may also help to have a picture of the wiring on the existing thermostat, in case a label falls off or if you need to reinstall the existing thermostat.
4. Remove your existing thermostat and back plate from the wall. Use care to not allow the cable to fall into the hole in the wall!
5. Mount the new back plate to the wall, using the appropriate method, for example, with the supplied drywall anchors. Position the plate, to cover the hole in the wall, and check the level of the plate, as needed. Do not overtighten the mounting screws, as this will warp the back plate, adversely impacting the thermostat operation.
6. Terminate each conductor on its respective screw terminal. You will need to loosen each screw terminal, first. When finished, gently tug on each wire, to ensure a good connection.
7. Refer to the rear of the Thermostat. Set the HP/GAS slide switch to HP for heat pump systems otherwise to GAS You can change the switch setting with a small screwdriver, pencil or similar object.

8. If you set the HP/GAS switch to HP, set the O/B slide switch to O for energizing the reversing valve on heating (cold climates) or B for energizing the reversing valve on cooling (hot climates) operation.

   If you set the HP/GAS switch to GAS, the valve will only energize for heating.

9. Gently push the thermostat down onto the back plate. You may hear an audible click, as it snaps into place. Observe the rear thermostat sides, near the wall, to ensure there are no uneven gaps between the plate and the thermostat. Gently tug on the thermostat, to ensure it does not come loose.
10. Turn on power to the unit. The Thermostat display should immediately turn on. If not, double-check your wire terminations, power-off the unit and correct any mistakes, as needed. If the thermostat still does not turn on, refer to the Troubleshooting, section U.

H. Get to Know Your Thermostat

Please take a moment to familiarize yourself with your new Thermostat.

1. Current day of the week

2. Current time of day

3. Current Date

4. Current temperature

5. Fahrenheit/Celsius indicator

6. Connection status (white if connected, red if disconnected)

7. Cooling set point

8. Temperature up button

9. Status (“Cooling” if in cooling mode, “Heating” if in heating mode)

10. Temperature down button

11. Heating set point

12. Schedule status (“RUN” if running on a schedule, “HOLD” if not running on a schedule

13. Schedule button (press to activate or deactivate schedules)

14. Fan status (“AUTO” if fan will run on demand, “ON” if the fan is on (running)

15. Fan button (press to switch the fan between Auto and On mode

16. Mode button (press to switch between system modes: Auto, Heat, Cool, Off)

17. Mode status (“AUTO” if cooling or heating automatically, “HEAT” if only heating is running, “COOL” if only cooling is running

18. Menu button (press to access the Thermostat’s menu system)

19. Menu indicator

20. Current humidity level (%)

21. ECO (Energy Conservation Operation) Leaf appears if in ECO mode

I. Set the Cooling or Heating Setpoint

1. First, tap the up or down button. Tap the appropriate buttons, to adjust the setpoint up or down.
2. When finished, tap the DONE button. To exit this process, tap the BACK button.

   a. Tap to raise the setpoint 

   b. Tap to lower the setpoint

   c. Tap to exit without saving 

   d. Tap to save your setpoint 

To avoid frequently turning the heating or cooling on and off, a 6 degree Fahrenheit/3 degree Celsius default, minimum, gap between the cooling and heating set points exists in all modes.

J. Navigating the Menu System

1. First, tap the MENU button.
2. Use the UP and DOWN buttons to navigate up or down the menu items
3. Use the ENTER button to select an item.
4. Tap DONE when finished, or tap BACK to exit without saving

a. Tap to raise the setpoint 

b. Tap to lower the setpoint

c. Tap to exit without saving 

d. Tap to save your setpoint 

K. Schedules: Editing & Copying

This section demonstrates viewing and editing the schedule from the thermostat. See section Q for viewing/editing from the app.

The Scheduling Submenu:

• One day of the week is displayed at a time. The current day is identified at the top of the screen, abbreviated Mon, Tue, Wed, etcetera. (To navigate to other days, tap the NEXT button.)
• Each day has up to four unique temperature adjustment events, labeled Wake, Leave, Return and Sleep.
• Each event has a heat and a cool setpoint. The current mode of the thermostat determines which setpoint is applied to the current schedule.
• You can schedule an entire day, then copy that schedule to other similar days, for identical schedules on those days, or as a starting point for a similar schedule, that you can edit to suit
• Use the left and right arrow buttons to navigate through each item that can be edited (hour, minute, heat setpoint, cool setpoint). Scrolling starts over at the first item after passing the last item (“Copy to”)

1. To edit a schedule, tap MENU. Navigate to Schedules, tap ENTER.
2. To change the selected day, tap the NEXT button until the correct day is displayed.
3. Use the left and right arrow buttons to navigate between items. Selected items are identified by green-colored text. Use the + and – buttons to change the item valve up or down. When correct, navigate to the next item using the left or right arrow buttons.
4. You can give edit each day of the week or you can copy the schedule of one day over to another day. This is explained in the next section.
5. After editing a day of the week that you wish to copy to another day, select Copy To. Tap the COPY button. A screen similar to the one below is displayed, showing the six other days of the week. Use the left and right arrow buttons to scroll between the days of the week. Each day is initially marked with an “N” which indicates it will not be updated with your copied schedule. Use the Y button to mark each day you wish to be updated with the copied schedule. After your Y/N selections have been made, tap the COPY button.
6. At this time, you can review your updated schedule, using the left and right arrow buttons. If finished editing, tap DONE to exit Schedules, then BACK to exit the menu system.

L. Y & Aux Config

This menu screen allows for configuring heat pump-related settings for the thermostat. If in doubt about the correct setting, please contact customer support (refer to the last page of this user guide).

Y OFF: Set to YES, if your compressor should turn off if the temperature is below your minimum level (determined in the next setting)

Y OFF under: This temperature, if Y OFF is set to YES, will determine at which temperatures the compressor will not operate (this temperature or less).

AUX only: For auxiliary heating only, select YES. The Y terminal will not turn on for heating, only AUX.

AUX stop time: This option sets a maximum time that auxiliary heating can run.

AUX degree: This setting determines the minimum temperature gap between the heat setpoint and the current temperature, before the aux heating will run.

M. Date & Time

This menu screen allows for changing the time and date. You have the option of either manually changing the time and date, or time and date being managed by the app. As the app uses your phone’s time and date, and as this is automatically updated and synchronized, setting Auto Update to YES is recommended. You can only edit the date and time if Auto Update is set to NO. 

Auto Update: Set to YES to allow the app to manage thermostat date and time

Format: Set to 12 for 12-hour format (e.g. 1:11 PM), set to 24 for 24 hour format (e.g. 13:11)

Time: Set the current time

Date: Set the current date

Day: Set the current day of the week

The time does not advance and the new settings are not updated until after the DONE button is pressed.

N. Temperature Settings

This menu screen allows for changing temperature-related settings for your Thermostat, such as Fahrenheit or Celsius format.

ECO: (Energy Conservation Operation). While in ECO mode, your thermostat will adjust your normal setpoint to a more economical setting (e.g. hotter setpoint in the summer), based on the offset number of degrees in the ECO setting.

ECO setting: This setting determines the number of degrees that the setpoint is adjusted, plus or minus actual setpoint values.

F/C Mode: Use this setting to switch between Fahrenheit and Celsius mode.

Calibration: If the thermostat temperature is different from the correct temperature (based on a calibrated thermometer, etc.), change this number to offset the displayed temperature by that amount. For example, if the actual temperature is .5 degrees colder, set this number to -0.5 °.

Current: The thermostat temperature is displayed, for reference. It will be adjusted per your calibration settings.

O. Display & Sound

This menu screen allows for changing settings related to the appearance and sound of your Thermostat. 

BG Color: Select Black or Blue background color

Brightness: Adjust screen brightness or intensity

BL Timeout: To maximize the life of the LCD display, brightness is typically adjusted down while not in use. You can adjust the duration before the display reverts to a low-brightness setting. Choose from one of the values between 10 and 180 seconds, or select Always, for no automatic dimming.

Sound: Select ON or OFF to enable or disable thermostat sounds.

P. Factory Reset

This menu screen provides access to factory reset and network reset functions. These functions are not typically used without the direction of a customer support agent or technician. Performing a factory reset will restore all settings to default. This will not harm your thermostat but you may be required to update any settings that are not automatically controlled or updated from the app. Factory reset will not delete the thermostat from the app.

Performing a network reset forces the thermostat to reconnect to the YoLink wireless network. If your thermostat is offline, performing a network reset may resolve the offline status.

Factory Reset: Select this item, then tap ENTER to start the factory reset. The display will go blank, and in a moment or two the thermostat should return to normal, online status. Verify the mode and settings are correct, otherwise update them as needed, either from the app or the thermostat.

Network Reset: Select this item, then tap ENTER to start a network reset. If your thermostat does not automatically reconnect to the YoLink network (indicated by the white signal indicator shown on the display) contact our Support department.

Q. App Functions: Device Screen

You have full access to thermostat functions and settings from the app. This section explains the main screen, known as the device screen, for the thermostat. This screen is your ‘everyday’ interface for the thermostat, and your alternative for remote control when the thermostat is not in reach. Refer to the next page for detailed explanations of each feature or element.

a. Device support

b. Device settings 

c. Connection status 

d. Swipe left or right to adjust the current setpoint 

e. Current temperature 

f. Heat/Cool Setpoints 

g. Status 

h. Current Humidity 

i. Setpoint up/down adjustment 

j. Indicates the current mode (green if active, Gray if inactive/disabled) 

k. Indicates the current run mode. Green = running on the schedule. Gray = not running on a schedule 

l. Indicates current fan mode (green if on, gray if auto) 

m. View/edit the schedule

n. View activity history

R. App Functions: Device Details Screen

This screen allows you to view and edit device settings, view various device status indicators, and perform a firmware update. Refer to the next page for a summary of each item.

a. Device type (Thermostat)

b. Device name. You can change the name. Tap to edit the device name

c. You can assign a device to a room, allowing for organizing your devices, especially helpful for larger systems

d. Tap to turn on the red heart icon. Devices marked as favorites will be displayed on the Favorites e. Tap to view the historical logs (heat, cool, etcetera) of the thermostat

f. Tap to enable ECO mode and set the ECO temperature offset

g. Displays the current online/offline state of the thermostat

h. Displays the current time, as reported by the thermostat. Tap Sync With Mobile to synchronize the thermostat’s time with the time on your phone

i. Thermostat model (YS4002 or YS4003)

j. The EUI is your thermostat’s unique ID number

k. The SN is your thermostat’s unique serial number

l. This figure indicates how strong the signal is from the nearest hub.

m. This number indicates the current firmware version. If a second number is shown with the words “Ready” there is a newer firmware version available. Electing to update the firmware is a manual process. Tap the word Ready to start the update. For additional information, visit the product support page on our website.

S. Automation

You can control thermostat modes via scenes or automations in the app. For example, you can automatically turn off the air conditioning or heat, if a door or window is left open. This example is shown below. The automation also sends a notification (via app push notification, email, SMS or SpeakerHub broadcast) reminding the door needs to be closed, before turning it back on.

Contact us, or visit our website support pages for information on automating and custom notifications.

T. Voice Assistants & Integrations

The YoLink Thermostat works with several voice assistants, including Alexa and Google, and it works with other automation platforms such as IFTTT. Visit the thermostat support pages on our website for up-to-date information.

To set up voice assistant integrations, in the app, go to Settings, Voice Assistants, and follow the instructions.

U. Troubleshooting

V. CE Mark Warning

The host manufacturer has the responsibility that the host device should be compliance with all essential requirement of RER. This restriction will be applied in all member states. The simplified UK declaration of conformity referred shall be provided as follows: Hereby, YoSmart Inc. declare that the radio equipment type YoLink SpeakerHub is in compliance with Directive UK Radio Equipment Regulations (SI 2017/1206); UK Electrical Equipment (Safety) Regulation (SI 2016/1101); and UK Electromagnetic Compatibility Regulations (SI 2016/1091).

W. FCC Statement

This equipment has been tested and found to comply with the limits for a Class B digital device, pursuant to part 15 of the FCC Rules. These limits are designed to provide reasonable protection against harmful interference in a residential installation. This equipment generates, uses and can radiate radio frequency energy and, if not installed and used in accordance with the instructions, may cause harmful interference to radio communications. However, there is no guarantee that interference will not occur in a particular installation. If this equipment does cause harmful
interference to radio or television reception, which can be determined by turning the equipment off and on, the user is encouraged to try to correct the interference by one or more of the following measures: Reorient or relocate the receiving antenna, connect the equipment into an outlet on a circuit different from that to which the receiver is connected, increase the separation between the equipment and receiver, consult the dealer or an experienced radio / TV technician for help.
This device complies with part 15 of the FCC Rules. Operation is subject to the following two conditions:
1) This device may not cause harmful interference
2) This device must accept any interference received, including interference that may cause
undesired operation. Any changes or modifications not expressly approved by the party responsible for compliance could void the user’s authority to operate the equipment.

X. 1-Year Warranty

YoSmart warrants to the original residential user of this product that it will be free from defects in materials and workmanship, under normal use, for 1 year from the date of purchase. User must provide a copy of original purchase receipt. This warranty does not cover abuse or misused products or products used in commercial applications. This warranty does not apply to YoLink devices that have been improperly installed, modified, put to a use other than designed, or subjected to acts of God (such as floods, lightning, earthquakes, etc.). This warranty is limited to repair or replacement of the YoLink device only at YoSmart's sole discretion. YoSmart will NOT be liable for the cost of installing, removing, nor reinstalling this product, nor direct, indirect, or consequential damages to persons or property resulting from the use of this product. This warranty only covers the cost of replacement parts or replacement units, it does not cover shipping & handling fees. Please contact us, to implement this warranty (see Customer Support, below, for contact information)

Y. Warnings

Please observe and adhere to the following warnings regarding the use of this product, as failure to do so can result in personal harm and/or property damage. YoSmart, Incorporated will not be held responsible for claims of liability due to improper use of our products.

• The thermostat must be powered by 24VAC, only. Other voltages will damage the thermostat.
• Do not install the thermostat in a dusty/dirty environment
• The thermostat is designed and intended for indoor use, only, and is not waterproof. Locate indoors, at a dry location.
• Please do not use strong chemicals or cleaning agents on the thermostat. Use a clean, dry cloth to wipe the thermostat to avoid dust and other foreign elements entering the thermostat and affecting the operation of the thermostat.
• Please contact Customer Support before attempting to repair, disassemble or modify the thermostat, any of which can void the warranty and permanently damage it.

W. Contact Us & Customer Support

We are here for you, if you ever need any assistance installing, setting up or using a YoLink app or product!

Need help? For fastest service, please email us 24/7 at service@yosmart.com

Or call us at 831-292-4831 (US phone support hours: Monday - Friday, 9 AM to 5 PM Pacific)

You can also find additional support and ways to contact us at: www.yosmart.com/support-and-service

Or scan the QR code:

Support Home Page

Finally, if you have any feedback or suggestions for us, please email us at feedback@yosmart.com

Thank you for trusting YoLink!

Eric Vanzo
Customer Experience Manager

15375 Barranca Parkway Ste. J-107 | Irvine, California 92618
© 2023 YOSMART, INC IRVINE, CALIFORNIA

• YS4003-UC_instruction.pdf2 MB