Salus RT520 Thermostat: Full User Manual

1. Introduction

1.1 Product Compliance

This product complies with the essential requirements and other relevant provisions of Directives 2014/53/EU and 2011/65/EU. The full text of the EU Declaration of Conformity is available at the following internet address: www.saluslegal.com.

1.2 Safety Informations

• Before starting installation work and before using the product, read the entire manual.
• The information contained in the instructions is essential for proper functioning.
• To avoid accidents resulting in personal injury and material damage, please follow all safety precautions specified in this manual.
• The device should not be used by people with limited mental, sensory or mental abilities, without experience, or insufficient knowledge, as well as children.
• Do not use an unassembled device (e.g., without a cover).
• The device may only be opened by a qualified person.
• Keep electrical devices out of the reach of children and ensure they do not play with them. Children should not be left unattended. If necessary, disconnect the control system for the entire room.
• Do not leave the packaging, cabinet, or any loose parts of the device unattended, as they pose a risk to children.

⚠️ WARNING!

• Installation must be carried out by a qualified person with appropriate electrical qualifications in accordance with standards and regulations in force in the given country and in the EU.
• Never try to connect the device other than as described in the manual.
• Before assembly, repair, or maintenance, as well as during any connection works, it is absolutely necessary to disconnect the mains supply and ensure that the terminals and electric wires are not live.
• The device may not be exposed to extreme temperatures, strong vibrations, or subjected to mechanical shock.
• The device should not be used in unfavorable environmental conditions or in rooms where there is a concentration of flammable gases, fumes, or dust.

⚠️ WARNING!

• There may be additional protection requirements for the entire installation that the installer is responsible for maintaining.

Care for the natural environment is of paramount importance. The awareness that we manufacture electronic devices obliges us to dispose of used electronic components and devices safely. The crossed-out symbol of a trash can on the product means that the product must not be disposed of with ordinary waste containers. Sorting waste for recycling helps to protect the environment. It is the user's responsibility to surrender used equipment to a designated collection point for recycling waste from electrical and electronic equipment.

2. Product Overview

The RT520 room thermostat switches the heating system on and off as necessary. It works by sensing the air temperature, switching on the heating when the air temperature falls below the thermostat setting, and switching it off once this set temperature has been reached.

Turning a room thermostat to a higher setting will not make the room heat up any faster. How quickly the room heats up depends on the design of the heating system, for example, the size of the boiler and radiators. Neither does the setting affect how quickly the room cools down. Turning a room thermostat to a lower setting will result in the room being controlled at a lower temperature, saving energy.

The heating system will not work if a time switch or programmer has switched it off.

The best way to set and use your room thermostat is to find the lowest temperature setting that you are comfortable with, and then leave it alone to do its job. Start by setting the thermostat to a low temperature (e.g., 18°C) and then increase it by one degree each day until you are comfortable. Any adjustment above this setting will waste energy and cost more money.

If your heating system is a boiler with radiators, there is usually only one room thermostat to control the whole house. You can achieve different temperatures in individual rooms by installing thermostatic radiator valves (TRVs) on individual radiators. If you don't have TRVs, choose a temperature that is reasonable for the whole house. If you do have TRVs, you can choose a slightly higher setting to ensure the coldest room is comfortable, then prevent overheating in other rooms by adjusting the TRVs.

Room thermostats need a free flow of air to sense the temperature, so they must not be covered by curtains or blocked by furniture. Nearby electric fires, televisions, wall or table lamps may prevent the thermostat from working properly.

The thermostat is compatible with OpenTherm OT+ 4.0 version. The OpenTherm protocol is an open standard communication protocol used in central heating systems for two-way communication between a central heating boiler and a room thermostat. This protocol allows the boiler power to be modulated, which can significantly increase energy efficiency while maintaining the set temperature. OpenTherm modulation, compared to standard communication (ON/OFF), occurs by setting the desired water temperature from the boiler, not by its cyclical switching on and off.

? PLEASE NOTE! Make sure your gas combi boiler is compatible with the OT+ 4.0 communication protocol. The list of compatible boilers is on the next page.

Product advantages:

• Automatically detects OT+ 4.0 protocol and regulates hot water temperature.
• Possibility to choose Hysteresis or built-in TPI algorithm for all types of heating.
• Works with time schedules.
• Service mode protected by a PIN code.
• Maximum / minimum temperature limitation.
• Can temporarily change the temperature (overwriting until the next program change).

2.1 Example of boilers compatible with the OpenTherm OT+ 4.0 protocol

2.2 Montage

2.3 Package content

• RT520 thermostat
• Back housing
• 2x AA batteries
• Short instruction
• Mounting screws

2.4 Proper thermostat location

The ideal position for thermostat mounting is about 1.5m above floor level, away from heating or cooling sources. The thermostat should not be exposed to direct sunlight or extreme conditions like drafts.

Due to fire and explosion risks, the thermostat is not allowed for use in atmospheres with explosive gases and flammable liquids (e.g., coal dust). If any of these dangers are present, use additional protection measures such as an anti-dust and explosive gases cover, or prevent their formation. Furthermore, the thermostat cannot be used in conditions of water vapor condensation or be exposed to water action.

2.5 Connection description

I A - Boiler connection (ON/OFF)

This connection uses the volt-free relay contacts (COM, NO, NC) on the thermostat to switch the boiler on or off.

Diagram description: RT520 thermostat with 3V 2xAA batteries connected to COM, NO, NC terminals. A boiler symbol is shown connected to COM and NO terminals, with a line indicating ON/OFF control.

I B - Pump / Valve connection

This connection allows the thermostat to control a pump or valve, typically rated up to 3(1)A.

Diagram description: AC 230V L/N power supply connected to the thermostat (3V 2xAA batteries) and to a pump/valve symbol via COM and NO terminals. The pump/valve symbol is labeled 'M' and has a fuse symbol.

I C - KL08NSB underfloor heating wiring center connection

This section details connecting the RT520 thermostat to a KL08NSB wiring center for underfloor heating systems, supporting multiple zones.

Diagram description: Shows multiple RT520 thermostats (or similar devices) connected to a KL08NSB unit. The KL08NSB has terminals for Power (AC 230V L/N), Zones (1-8), Pump, and Boiler. It also shows T30NC actuators for each zone. The diagram illustrates connections between thermostats, the KL08NSB, and the boiler. The OpenTherm connection (A/B) is also shown.

Legend:

• Boiler connection*: Boiler's contacts for ON/OFF thermostat (according to the boiler's instructions).
• Pump
• Valve

Symbols explanation:

• L, N - power supply 230V
• NO, COM, NC - voltage-free output
• A, B - OpenTherm Communication Wire
• SL - 230V AC voltage output
• - NSB function
• - fuse

3. Before you start (first power up)

3.1 LCD icon description

The LCD screen displays various icons and information:

• 1. Text Bar: Displays messages and settings.
• 2. Temperature Unit: °C or °F.
• 3A/3B. Day of the week: Numeric or alphabetic display.
• 4. Clock: Current time.
• 5. AM / PM: Time indicator.
• 6. Cooling Mode On: Icon indicating cooling is active.
• 7. Holiday Mode On: Icon indicating holiday mode is active.
• 8. Manual Mode On: Icon indicating manual mode is active.
• 9. Heating Mode On: Icon indicating heating is active.
• 10. Low battery status: Icon indicating batteries need replacement.
• 11. Wireless connection with the receiver: Icon indicating connection status.
• 12. Service Mode On: Icon indicating service mode is active.
• 13. Temperature measured / set: Displays current and set temperatures.
• 14. Program number: Indicates the current program step.
• 15. Settings: Access to settings menu.
• 16. Program indicator: Shows program status.
• 17. Boost function: Icon indicating boost mode is active.

3.2 Button description

The thermostat has six buttons:

• 1. MENU / RETURN: Enter menu options. Press and hold for 3 seconds to return to the main screen or deactivate Boost/Manual modes.
• 2. SELECT: Confirm changes and enter menus.
• 3. DOWN: Decrease the temperature and move through menus.
• 4. UP: Increase the temperature and move through menus.
• 5. BOOST: Activate Boost Mode.
• 6. MANUAL: Press once to activate Manual Mode; press and hold for 3 seconds to deactivate it.

? PLEASE NOTE! The LCD screen can be activated by using any button.

3.3 First power up sequence and configuration

Important: Please make the receiver connections and power the receiver before inserting the batteries into the thermostat.

1. After inserting the batteries, the thermostat will power up.
2. The screen will display "LANGUAGE". Press the [Select] button.
3. Use the [Up] or [Down] buttons to choose your language (e.g., ENGLISH) and then press [Select].
4. The screen will display "TIME 24hr". Use the [Up] or [Down] buttons to choose the time format (24hr or 12hr) and then press [Select].
5. The screen will display "TIME 88:88". Use the [Up] or [Down] buttons to set the hour and then press [Select].
6. The screen will display "TIME 88:88". Use the [Up] or [Down] buttons to set the minutes and then press [Select].
7. The screen will display "YEAR 18". Use the [Up] or [Down] buttons to set the year and then press [Select].
8. The screen will display "MONTH 01". Use the [Up] or [Down] buttons to set the month and then press [Select].
9. The screen will display "DAY 01". Use the [Up] or [Down] buttons to set the day and then press [Select].
10. The screen will display "DISPLAY" with week options (MON, TUE, etc.). Use the [Up] or [Down] buttons to select the week format and then press [Select].
11. The screen will display "DST_ON" or "DST_OFF". Use the [Up] or [Down] buttons to enable or disable DST (Daylight Saving Time) and then press [Select].
12. The screen will display "DISPLAY" with temperature accuracy options (e.g., 0.5). Use the [Up] or [Down] buttons to select your desired temperature accuracy and then press [Select].
13. If OpenTherm is connected, the device software will automatically adjust to the OpenTherm settings.
14. The screen will display "TPI". Press [Select].
15. The thermostat offers 3 types of TPI control: 1. for radiator (6CPH); 2. for underfloor heating (3CPH); 3. for electric heating (9CPH). Use the [Up] or [Down] buttons to select the TPI type you want to use and then press [Select].
16. The screen will display "SPAN". Press [Select].
17. "Span" is the difference between the measured temperature and the set temperature. Use the [Up] or [Down] buttons to select the Span value (e.g., 0.5s or 0.25s) and then press [Select].
18. The screen will display "OPTIMIZE". Press [Select].
19. The optimization function is an energy-saving algorithm. When OPTIMUM START is active, the thermostat signals the heat source beforehand so that the preset temperature is reached at the scheduled time.
20. The screen will display "OPTIMUM START". Use the [Up] or [Down] buttons to select ON or OFF and press [Select] to confirm.
21. The screen will display "OPTIMUM STOP". Use the [Up] or [Down] buttons to select ON or OFF and press [Select] to confirm. When OPTIMUM STOP is active, the thermostat switches off the heat source earlier, considering system inertia, to maintain the scheduled temperature.
22. The thermostat will then go to the main screen.

3.4 OpenTherm - Hot Water configuration

The RT520 can be configured in a Hot Water OpenTherm system. To configure it, follow these steps:

1. From the main screen, press the [Select] button.
2. Navigate to the "HOTWATER" submenu using the [Up] or [Down] buttons and press [Select].
3. Use the [Up] or [Down] buttons to adjust the hot water temperature and then press [Select].
4. The screen will display "HW ON". The text bar indicates that hot water is in operation.
5. The thermostat will return to the main screen. Press any button to confirm.

3.5 Max boiler temperature settings

This section explains how to set the maximum temperature for the connected boiler.

1. From the main screen, press the [Select] button.
2. Navigate to the "CH MAX" submenu using the [Up] or [Down] buttons and press [Select].
3. The screen will display "TEMP". Confirm by pressing the [Select] button.
4. Use the [Up] or [Down] buttons to set the maximum temperature for the boiler and confirm by pressing the [Select] button.
5. The thermostat will go back to the main screen, saving all settings.

4. User settings

4.1 Manual mode

In manual mode, the thermostat maintains a constant temperature set by the user. To exit manual mode, press and hold the [Menu/Return] button for 3 seconds. A hand icon ?️ is displayed when manual mode is active.

1. From the main screen, press the [Manual] button.
2. A hand icon ?️ will appear, indicating the thermostat is in manual mode.
3. To set the temperature, use the [Up] or [Down] buttons.
4. Confirm your choice using the [Select] button.
5. The thermostat will maintain the set temperature until manually changed or until manual mode is exited (by pressing and holding the [Menu/Return] button for 3 seconds).

4.2 Schedule mode - programming schedule

In this mode, you can set schedules for the thermostat (temperature setpoints for specific periods of time). Programmed schedules should utilize all time periods.

1. From the main screen, press the [Select] button.
2. Navigate to "SCHEDULE" using the [Up] or [Down] buttons and press [Select].
3. Use the [Up] or [Down] buttons to select the program type:
• +2: Schedule for working days and the weekend.
• All: Set one schedule for the entire week.
• Individual: Set a daily schedule.
4. Press [Select] to confirm your choice.
5. Use the [Up] or [Down] buttons to set the hour and then press [Select].
6. Use the [Up] or [Down] buttons to set the minutes and then press [Select].
7. Use the [Up] or [Down] buttons to set the temperature and then press [Select].
8. Repeat the process for all time periods.

4.3 Switching between manual and schedule mode

You can switch between manual and schedule mode using the [Manual] button. Follow these steps:

1. From the main screen, press the [Manual] button.
2. A hand icon ?️ will appear, indicating the thermostat is in manual mode.
3. Now, press and hold the [Menu/Return] button for 3 seconds.
4. The thermostat will return to the schedule mode.

4.4 BOOST mode - hourly temperature override (+Hr)

This function is available in automatic and manual modes. It allows you to change the temperature to a desired value for a specified number of hours (up to 9 hours). After the elapsed time, the thermostat returns to the previous operating mode.

To activate BOOST mode:

1. Press the [+Hr] button to set the duration for the temporary override (e.g., 4 hours = 4 presses). Confirm by pressing the [Select] button.
2. Use the [Up] or [Down] buttons to set the desired temperature for BOOST mode. Confirm by pressing the [Select] button.
3. The thermostat will now operate in BOOST mode for the set duration, maintaining the specified temperature.

How to stop BOOST mode:

1. Hold the [Menu/Return] button for 3 seconds, or press the [+Hr] button several times until "+0" appears.
2. Confirm by pressing the [Select] button.
3. The thermostat will return to the main screen and its previous operating mode.

4.5 Control and Heat/Cool settings

In this section, you can set the control algorithm (TPI, SPAN, or Optimize) and the Heat/Cool mode.

1. From the main screen, press the [Select] button.
2. Navigate to "SCHEDULE" using the [Up] or [Down] buttons and press [Select].
3. Navigate to "CONTROL" using the [Up] or [Down] buttons and press [Select].
4. Use the [Up] or [Down] buttons to move between parameters (TPI, SPAN, Optimize).
5. Navigate to "HEATCOOL" using the [Up] or [Down] buttons and press [Select].
6. Use the [Up] or [Down] buttons to select "HEAT" or "COOL" mode and confirm your choice by pressing the [Select] button.

4.6 OFFSET temperature calibration

This chapter explains how to calibrate the temperature on the RT520 thermostat. Calibration is possible in the range from -3.5°C to 3.5°C (in steps of 0.5°C).

1. From the main screen, press the [Select] button.
2. Navigate to "SCHEDULE" using the [Up] or [Down] buttons and press [Select].
3. Navigate to "CONTROL" using the [Up] or [Down] buttons and press [Select].
4. Navigate to "OFFSET" using the [Up] or [Down] buttons and press [Select].
5. Use the [Up] or [Down] buttons to calibrate the temperature. Confirm your choice by pressing the [Select] button.

4.7 Landlord settings

Landlord settings is a PIN code protected feature that allows the landlord to set a service reminder on the thermostat, warning the tenant when the boiler is due its annual service.

1. From the main screen, press the [Select] button.
2. Navigate to the "LANDLORD" submenu using the [Up] or [Down] buttons and press [Select].
3. Enter the PIN code number using the [Up] or [Down] buttons, pressing [Select] to confirm each digit. Note: The first PIN code entry also sets a NEW PIN CODE, which must be entered each time to access the LANDLORD (Admin) menu.
4. ? PLEASE NOTE: Remember to write down your PIN code so you can use the Landlord menu later without hassle.
5. Navigate to "SERVICE" using the [Up] or [Down] buttons and press [Select].
6. Use the [Up] or [Down] buttons to select ON or OFF and press [Select] to confirm.
7. Use the [Up] or [Down] buttons to select the due date and then press [Select].
8. Use the [Up] or [Down] buttons to select the warning period and then press [Select].
9. Use the [Up] or [Down] buttons to select the lock temperature and then press [Select].
10. Press the [Select] button.
11. Use the [Up] or [Down] buttons to enter the phone number, pressing [Select] to confirm each digit.
12. To confirm and exit this option, use the [Select] button. Then use the [Up] or [Down] buttons to move to the next LANDLORD options.
13. Use the [Up] or [Down] buttons to move to the next option.
14. Press the [Select] button.
15. Use the [Up] or [Down] buttons to select the correct MAX temperature setpoint value. Confirm by pressing the [Select] button.
16. Now, use the [Up] or [Down] buttons to select the correct MIN temperature setpoint value. Confirm by pressing the [Select] button.
17. The thermostat will go back to the SERVICE option. To return to the main screen, wait 10 seconds or press the [Menu/Return] button until the main screen is displayed.

4.8 Time/Date

To set time/date, follow these steps:

1. From the main screen, press the [Select] button.
2. Navigate to "SCHEDULE" using the [Up] or [Down] buttons and press [Select].
3. Navigate to "TIMEDATE" using the [Up] or [Down] buttons and press [Select] to enter Time/Date settings.
4. Use the [Up] or [Down] buttons to choose the time format (24hr or 12hr). Press [Select] to confirm.
5. Use the [Up] or [Down] buttons to set the hour and then press [Select].
6. Use the [Up] or [Down] buttons to set the minutes and then press [Select].
7. Use the [Up] or [Down] buttons to set the year and then press [Select].
8. Use the [Up] or [Down] buttons to set the month and then press [Select].
9. Use the [Up] or [Down] buttons to set the day and then press [Select].
10. Use the [Up] or [Down] buttons to select the week format. Press [Select] to confirm.
11. Use the [Up] or [Down] buttons to enable or disable DST (Daylight Saving Time). Press [Select] to confirm.
12. The thermostat will go to the main screen, saving all settings.

4.9 Holiday mode

Holiday mode is a special program temperature setpoint that the thermostat will maintain for specified days. To set HOLIDAY MODE:

1. From the main screen, press the [Select] button.
2. Navigate to "SCHEDULE" using the [Up] or [Down] buttons and press [Select].
3. Navigate to "HOLIDAY" using the [Up] or [Down] buttons and press [Select] to enter holiday mode settings.
4. Use the [Up] or [Down] buttons to set the year and then press [Select].
5. Use the [Up] or [Down] buttons to set the month and then press [Select].
6. Use the [Up] or [Down] buttons to set the day and then press [Select].
7. Now, do the same steps to set holiday mode's final day.
8. Use the [Up] or [Down] buttons to set the hour and then press [Select].
9. Use the [Up] or [Down] buttons to set the minutes and then press [Select].
10. Use the [Up] or [Down] buttons to set the temperature which should be maintained during holiday mode and then press [Select].
11. According to the set period of time, a plane icon ✈️ will appear on the main screen, and the thermostat is working in holiday mode.
12. To abort holiday mode, just press any button and then confirm "HOLIDAY STOP" by pressing the [Select] button. The plane icon ✈️ will disappear, and the thermostat will go back to the previous work mode.

4.10 Language

To choose the language, follow these steps:

1. From the main screen, press the [Select] button.
2. Navigate to "SCHEDULE" using the [Up] or [Down] buttons and press [Select].
3. Navigate to "LANGUAGE" using the [Up] or [Down] buttons and press [Select] to enter language settings.
4. Use the [Up] or [Down] buttons to choose your language (e.g., POLSKI, ENGLISH).
5. Press [Select] to confirm.
6. The thermostat will go to the main screen, saving the changes.

5. Factory Reset

To reset the RT520 thermostat to its factory default settings, follow these steps:

1. From the main screen, press and hold together the [Up], [Down], and [+Hr] buttons for 5 seconds.
2. The thermostat has been reset. PLEASE NOTE: User settings will not be deleted.

6. Error codes

The thermostat will display errors only when it's connected to the boiler by OpenTherm terminals (A / B). Please refer to the boiler manual, as each boiler can have different error codes.

7. Battery change

Turn the thermostat over so that the back is in front of you. Insert the batteries, paying attention to their polarity (+ and -).

8. Cleaning and Maintenance

The RT520 thermostat requires no special maintenance. Periodically, the outer casing can be wiped clean using a dry cloth. Please DO NOT use solvents, polishes, detergents, or abrasive cleaners, as these can damage the thermostat. There are no user-serviceable parts within the unit; any servicing or repairs should only be carried out by Salus Controls or their appointed agents.

9. Technical Informations

Dimensions: Height: 95 mm, Width: 118 mm, Depth: 26 mm.

10. Warranty

SALUS CONTROLS warrants this product to be free from any defects in material or workmanship and to perform as specified for a period of five years from the date of installation. SALUS CONTROLS reserves the sole responsibility for breach of this warranty by repairing or replacing the defective product. This product includes software that matches the distributor's identification at the time of sale. The manufacturer / distributor provides a guarantee covering all functions and specifics of the product in accordance with this marking. The distributor's warranty does not cover the correct operation of the functions and features available as a result of a product software update.

The full warranty conditions are available at www.salus-controls.eu.