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, of 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 that they do not play with it. 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 make sure 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.

2. Product Overview

The RT520 room thermostat simply 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 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, and saves energy.

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

The 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. The best way to do this is to set the room thermostat to a low temperature – say 18°C – and then turn it up by one degree each day until you are comfortable with the temperature. You won't have to adjust the thermostat further. Any adjustment above this setting will waste energy and cost you more money.

If your heating system is a boiler with radiators, there will usually be only one room thermostat to control the whole house. But you can have different temperatures in individual rooms by installing thermostatic radiator valves (TRVs) on individual radiators. If you don't have TRVs, you should choose a temperature that is reasonable for the whole house. If you do have TRVs, you can choose a slightly higher setting to make sure that even the coldest room is comfortable, then prevent any 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. Thanks to the communication protocol, the boiler power is modulated, which can significantly increase the energy efficiency of the heating system while maintaining the set temperature in the room. OpenTherm modulation, compared to standard communication (ON / OFF), occurs by setting the desired temperature of water from the boiler (boiler power), and not by its cyclical switching on and off.

⚠️ PLEASE NOTE! Make sure your gas combi boiler is compatible with 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).

Care for the natural environment is of paramount importance to us. The awareness that we manufacture electronic devices obliges us to dispose of used electronic components and devices safely. Therefore the company has received a registration number issued by the Chief Inspector for Environmental Protection. The crossed out trash can symbol ?️ 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.

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

2.2 Montage

Refer to the diagrams for physical mounting instructions. The RT520 thermostat is typically mounted on a wall using the provided back housing and screws.

2.3 Package content

• 1) RT520 thermostat
• 2) Back housing
• 3) 2x AA batteries ?
• 4) Short instruction
• 5) Mounting screws

2.4 Proper thermostat location

The ideal position for thermostat mounting is approximately 1.5 meters above floor level, away from direct heating or cooling sources, direct sunlight, or drafts. Avoid placing the thermostat in atmospheres with explosive gases or flammable liquids. It should not be exposed to condensation or water action.

2.5 Connection description

IA - Boiler connection

Connect the boiler's ON/OFF terminals (according to the boiler's instructions) to the thermostat's voltage-free output (NC, COM, NO).

IB - Pump / Valve connection

Connect the pump or valve control to the thermostat's voltage-free output (NC, COM, NO) and the 230V AC power supply (L, N).

IC - KL08NSB underfloor heating wiring center connection

Connect the thermostat's voltage-free output (COM, NO) to the KL08NSB wiring center. The wiring center distributes signals to zones, power, pump, and boiler. OpenTherm communication wires (A, B) should also be connected if applicable.

3. Before you start (first power up)

3.1 LCD icon description

• 1. Text Bar
• 2. Temperature Unit (°C)
• 3A. Day of the week (numeric)
• 3B. Day of the week (alphabetic)
• 4. Clock
• 5. AM/PM indicator
• 6. Cooling Mode On ❄️
• 7. Holiday Mode On ✈️
• 8. Manual Mode On ✋
• 9. Heating Mode On ?
• 10. Low battery status ?
• 11. Wireless connection with the receiver
• 12. Service Mode On ⚙️
• 13. Temperature measured / set
• 14. Program number
• 15. Settings menu
• 16. Program indicator
• 17. Boost function (+Hr)

3.2 Button description

• 1. ↩️ [MENU/RETURN]: Enter menu options, press and hold for 3 sec to return to main screen or deactivate Boost/Manual modes.
• 2. ✔️ [SELECT]: Confirm changes and enter menus.
• 3. ⬇️ [DOWN]: Decrease temperature and move through menus.
• 4. ⬆️ [UP]: Increase temperature and move through menus.
• 5. ? [BOOST]: Activate Boost Mode.
• 6. ✋ [MANUAL]: Press once to activate; press and hold for 3 sec to deactivate Manual Mode.

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

3.3 First power up sequence and configuration

Make receiver connections and power the receiver before inserting batteries into the thermostat.

1. After inserting batteries, the thermostat powers up.
2. Press the ✔️ [SELECT] button.
3. Using ⬆️/⬇️ buttons, choose your language (e.g., ENGLISH) and press ✔️ [SELECT].
4. Using ⬆️/⬇️ buttons, choose the time format (24 hr or 12 hr) and press ✔️ [SELECT].
5. Set the hour using ⬆️/⬇️ buttons, then press ✔️ [SELECT].
6. Set the minutes using ⬆️/⬇️ buttons, then press ✔️ [SELECT].
7. Set the year using ⬆️/⬇️ buttons, then press ✔️ [SELECT].
8. Set the month using ⬆️/⬇️ buttons, then press ✔️ [SELECT].
9. Set the day using ⬆️/⬇️ buttons, then press ✔️ [SELECT].
10. Using ⬆️/⬇️ buttons, select the week format (e.g., MON-SUN) and press ✔️ [SELECT].
11. Using ⬆️/⬇️ buttons, enable or disable DST (Daylight Saving Time) and press ✔️ [SELECT].
12. Using ⬆️/⬇️ buttons, select your temperature accuracy (e.g., 0.1°C or 0.5°C) and press ✔️ [SELECT].
13. If OpenTherm is connected, the device software will automatically adjust to the OpenTherm settings.
14. Select TPI type: Using ⬆️/⬇️, select the TPI type (TPI RAD, TPI UFH, TPI ELEC) and press ✔️ [SELECT].
15. Set Span value: Span is the difference between measured and set temperature. Using ⬆️/⬇️, select the Span value (e.g., 1.5) and press ✔️ [SELECT].
16. Optimize function: Using ⬆️/⬇️, select ON or OFF for OPTIMUM START and press ✔️ [SELECT].
17. Optimize function: Using ⬆️/⬇️, select ON or OFF for OPTIMUM STOP and press ✔️ [SELECT].
18. The thermostat will go to the main screen.

3.4 OpenTherm - Hot Water configuration

To configure the RT520 for Hot Water using the OpenTherm system, follow these steps:

1. Press the ✔️ [SELECT] button.
2. Navigate to the 'Hot Water' submenu using ⬆️/⬇️ buttons and press ✔️ [SELECT].
3. Adjust the desired hot water temperature using ⬆️/⬇️ buttons and press ✔️ [SELECT].
4. The text bar will indicate that hot water is in operation. The thermostat will return to the main screen.

4. User settings

4.1 Manual mode

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

1. Press the ✋ [MANUAL] button. A hand icon ✋ will appear.
2. To set the desired temperature, use the ⬆️/⬇️ buttons.
3. Confirm your choice using the ✔️ [SELECT] button. The thermostat will maintain this temperature until a manual change or exit from manual mode.

4.2 Schedule mode - programming schedule

In this mode, users can set temperature setpoints for specific periods of the day. Programmed schedules should utilize all time periods.

1. Press the ✔️ [SELECT] button.
2. Press the SCHEDULE button.
3. Using ⬆️/⬇️ buttons, select the program type: 5+2 (weekdays/weekend), All (one schedule for the week), or Individual (daily schedule). Press ✔️ [SELECT].
4. Set the hour using ⬆️/⬇️ buttons, then press ✔️ [SELECT].
5. Set the minutes using ⬆️/⬇️ buttons, then press ✔️ [SELECT].
6. Set the temperature using ⬆️/⬇️ buttons, then press ✔️ [SELECT].
7. Repeat the process for all time periods. Press ✔️ [SELECT] to confirm.

4.3 Switching between manual and schedule mode

To switch between manual and schedule mode, use the ✋ [MANUAL] button. To switch to manual mode, press the ✋ [MANUAL] button; a hand icon ✋ will appear. To switch back to schedule mode, press and hold the ↩️ [MENU/RETURN] button for 3 seconds.

4.4 BOOST mode - hourly temperature override (+Hr)

This function is available in automatic and manual modes. It allows changing 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 ? [BOOST] button (+Hr).
2. Press the ? [BOOST] button multiple times to set the desired number of hours (e.g., 4 presses for 4 hours).
3. Using ⬆️/⬇️ buttons, set the temperature for BOOST mode.
4. Confirm by pressing the ✔️ [SELECT] button. The thermostat will maintain the set temperature for the specified duration.

How to stop BOOST mode:

1. Press and hold the ↩️ [MENU/RETURN] button for 3 seconds, or press the ? [BOOST] button multiple times until "+0" appears.
2. Confirm by pressing the ✔️ [SELECT] button. The thermostat will return to the main screen and previous work mode.

4.5 Control and Heat/Cool settings

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

1. Press the ✔️ [SELECT] button to enter the settings menu.
2. Navigate to 'CONTROL' using ⬆️/⬇️ buttons and press ✔️ [SELECT].
3. Using ⬆️/⬇️, move between parameters (TPI, SPAN, HEAT/COOL).
4. For TPI, select the desired type (RAD, UFH, ELEC) and press ✔️ [SELECT].
5. For SPAN, set the value (e.g., 1.5) and press ✔️ [SELECT].
6. For HEAT/COOL, select HEAT or COOL mode and press ✔️ [SELECT].
7. For Optimize, select ON or OFF for OPTIMUM START and OPTIMUM STOP, pressing ✔️ [SELECT] after each.

4.6 Landlord settings

Landlord settings is a PIN code protected feature that allows setting a service reminder for the tenant. The default PIN is 0000. A new PIN must be set upon first entry.

1. Press the ✔️ [SELECT] button.
2. Navigate to 'LANDLORD' using ⬆️/⬇️ buttons and press ✔️ [SELECT].
3. Enter the PIN code number using ⬆️/⬇️ buttons and press ✔️ [SELECT] for each digit.
4. Navigate to 'SERVICE' using ⬆️/⬇️ buttons and press ✔️ [SELECT].
5. Select 'ON' for service reminder and press ✔️ [SELECT].
6. Select the due date for the service using ⬆️/⬇️ buttons and press ✔️ [SELECT].
7. Select the warning period (days before due date) using ⬆️/⬇️ buttons and press ✔️ [SELECT].
8. Navigate to 'LOCKTEMP' using ⬆️/⬇️ buttons and press ✔️ [SELECT].
9. Set the maximum temperature limit using ⬆️/⬇️ buttons and press ✔️ [SELECT].
10. Set the minimum temperature limit using ⬆️/⬇️ buttons and press ✔️ [SELECT].
11. Navigate to 'PHONE' using ⬆️/⬇️ buttons and press ✔️ [SELECT].
12. Enter the phone number for service reminders using ⬆️/⬇️ buttons and press ✔️ [SELECT] for each digit.
13. To confirm and exit, use the ↩️ [MENU/RETURN] button. Further LANDLORD options can be accessed by navigating through the menu.

4.7 Time/Date

To set the time and date, follow these steps:

1. Press the ✔️ [SELECT] button.
2. Navigate to 'TIMEDATE' using ⬆️/⬇️ buttons and press ✔️ [SELECT].
3. Choose the time format (24 hr or 12 hr) using ⬆️/⬇️ buttons and press ✔️ [SELECT].
4. Set the hour using ⬆️/⬇️ buttons, then press ✔️ [SELECT].
5. Set the minutes using ⬆️/⬇️ buttons, then press ✔️ [SELECT].
6. Set the year using ⬆️/⬇️ buttons, then press ✔️ [SELECT].
7. Set the month using ⬆️/⬇️ buttons, then press ✔️ [SELECT].
8. Set the day using ⬆️/⬇️ buttons, then press ✔️ [SELECT].
9. Select the week format (e.g., MON-SUN) using ⬆️/⬇️ buttons and press ✔️ [SELECT].
10. Enable or disable DST (Daylight Saving Time) using ⬆️/⬇️ buttons and press ✔️ [SELECT].
11. The thermostat will return to the main screen with all settings saved.

4.8 Holiday mode

Holiday mode sets a special program temperature setpoint that the thermostat will maintain for specified days.

1. Press the ✔️ [SELECT] button.
2. Navigate to 'HOLIDAY' using ⬆️/⬇️ buttons and press ✔️ [SELECT].
3. Set the start year using ⬆️/⬇️ buttons, then press ✔️ [SELECT].
4. Set the start month using ⬆️/⬇️ buttons, then press ✔️ [SELECT].
5. Set the start day using ⬆️/⬇️ buttons, then press ✔️ [SELECT].
6. Set the end year using ⬆️/⬇️ buttons, then press ✔️ [SELECT].
7. Set the end month using ⬆️/⬇️ buttons, then press ✔️ [SELECT].
8. Set the end day using ⬆️/⬇️ buttons, then press ✔️ [SELECT].
9. Set the hour using ⬆️/⬇️ buttons, then press ✔️ [SELECT].
10. Set the minutes using ⬆️/⬇️ buttons, then press ✔️ [SELECT].
11. Set the desired holiday temperature using ⬆️/⬇️ buttons, then press ✔️ [SELECT].
12. A plane icon ✈️ will appear on the main screen, indicating the thermostat is in holiday mode.

To abort holiday mode: Press any button, then confirm 'HOLIDAY STOP' by pressing the ✔️ [SELECT] button. The plane icon will disappear, and the thermostat will return to its previous work mode.

4.9 Language

To choose the display language:

1. Press the ✔️ [SELECT] button.
2. Navigate to 'LANGUAGE' using ⬆️/⬇️ buttons and press ✔️ [SELECT].
3. Using ⬆️/⬇️ buttons, choose your desired language (e.g., ENGLISH) and press ✔️ [SELECT].
4. The thermostat will return to the main screen with the changes saved.

5. Factory Reset

To reset the RT520 thermostat to its factory default settings, press and hold the ? [BOOST] and ✋ [MANUAL] buttons together for 5 seconds. The thermostat will reset, and user settings will not be deleted.

6. Error codes

Error codes are displayed only when the thermostat is connected to the boiler via OpenTherm terminals (A/B). Refer to your boiler manual for specific error code meanings, as each boiler may have different codes.

7. Battery change

Turn the thermostat over. Insert 2x AA batteries, paying attention to their polarity.

8. Cleaning and Maintenance

The RT520 thermostat requires minimal maintenance. Periodically wipe the outer casing with a dry cloth. Do not use solvents, polishes, detergents, or abrasive cleaners, as they can damage the thermostat. There are no user-serviceable parts inside; any servicing or repairs must be carried out by Salus Controls or their appointed agents.

9. Technical Informations

10. Warranty

SALUS CONTROLS warrants this product to be free from defects in material or workmanship for a period of five years from the date of installation. For full warranty conditions, visit www.salus-controls.eu.