SALUS RT520, RT520TX, RT520RF Thermostats

Product Introduction

The SALUS RT520 and RT520RF thermostats are the latest models in the established RT series. The new, built-in temporary temperature change function offers the best solution, ensuring optimal efficiency and maximum comfort for heating control for the homeowner. Wired and wireless thermostats are available. They are equipped with all the functions of previous RT series models. Additionally, they feature a more intuitive LCD display and new, additional functions that improve operability and efficiency.

Please read these instructions before use.

Product Compliance

Directives: Electromagnetic Compatibility Directive EMC 2014/30/EU, Low Voltage Directive LVD 2014/35/EU, Radio Directive RED 2014/53/EU, and RoHS Directive 2011/65/EU.

Radio Frequency: 868.0-868.6MHz; <13dBm

Safety

Use in accordance with applicable national and European regulations. Use only for its intended purpose, avoid moisture. The product is for indoor use only. Installation should be carried out by an authorized and qualified person, in accordance with applicable national and European regulations.

Before installing or commissioning any parts (including battery replacement), always ensure that the mains power supply is switched off. Use only AA 1.5V alkaline batteries. Insert batteries into the battery compartment on the back of the thermostat. Do not use rechargeable batteries.

Technical Specifications

Button Functions

RT520/RT520RF Thermostat

• [MENU] - Menu options; hold for 3 seconds to return to the main screen or exit Boost mode.
• [SELECT] - Confirm changes, enter menu.
• [DOWN] - Decrease set temperature, allows navigation through the menu.
• [UP] - Increase set temperature, allows navigation through the menu.
• [BOOST] - Activate Boost mode.
• [MANUAL] - Activate/deactivate manual mode.

RXRT520 Receiver

• [ON] - In manual mode, activates the boiler.
• [OFF] - In manual mode, deactivates the boiler.
• [AUTO] - The receiver operates in automatic mode according to thermostat settings.
• [MANUAL] - Receiver control via On/Off slide switch.

RT520TX Thermostat (Transmitter)

(Buttons are the same as RT520/RT520RF Thermostat)

LCD Symbol Description

• 1 [MESSAGE_BAR]: Message bar
• 2 [TEMP_UNIT]: Temperature unit (°C)
• 3A [DAY_NUM]: Day of the week (by number)
• 3B [DAY_WORD]: Day of the week (by word)
• 4 [HOUR]: Clock
• 5 [AM_PM]: AM/PM indicator
• 6 [COOLING]: Cooling mode active
• 7 [HOLIDAY]: Holiday mode active
• 8 [MANUAL_MODE]: Manual mode active
• 9 [HEATING]: Heating mode active
• 10 [LOW_BATTERY]: Low battery level
• 11 [WIRELESS_CONN]: Wireless connection with receiver
• 12 [SERVICE_MODE]: Service mode active
• 13 [MEASURED_TEMP]/[SET_TEMP]: Measured/set temperature
• 14 [PROG_NO]: Program number
• 15 [SETTINGS]: Settings
• 16 [CURRENT_PROG]: Current program
• 17 [BOOST_FUNC]: Boost function

RT520 Thermostat Electrical Connections Description

RXRT520 Receiver Electrical Connections Description

Wiring Diagrams

RT520TX Wiring Diagram (TPI, Hysteresis, OpenTherm)

Shows connections between RT520TX thermostat, RXRT520 receiver, and boiler/heating system components. Includes OpenTherm terminals (A/B) and standard relay outputs (COM, NO, NC) for boiler control. Power supply (AC 230V) connections for the receiver are also indicated.

RT520 Wiring Diagram (TPI, Hysteresis, OpenTherm)

Similar to the RT520TX diagram, illustrating connections for the RT520 thermostat, RXRT520 receiver, and heating system. Features OpenTherm terminals (A/B) and relay outputs (COM, NO, NC) for boiler control, along with AC 230V power supply for the receiver.

OpenTherm - Start-up and Configuration

Modulating control via the OpenTherm protocol is a method used in modern heating systems. Instead of switching the boiler on and off according to a set schedule, modulating control allows for regulation of the heat output from the boiler, adapting to the thermostat's variable demand. This increases system efficiency. Using these thermostats ensures greater energy savings and increased comfort.

Before installing batteries in the thermostat, the receiver must be correctly connected and powered.

1. Thermostat powers on after battery installation.
2. Press [SELECT].
3. Use [UP]/[DOWN] buttons to select language, then press [SELECT].
4. Use [UP]/[DOWN] buttons to select time format (24 hr / 12 hr), then press [SELECT].
5. Use [UP]/[DOWN] buttons to set the hour, then press [SELECT].
6. Use [UP]/[DOWN] buttons to set the minute, then press [SELECT].
7. Use [UP]/[DOWN] buttons to set the year, then press [SELECT].
8. Use [UP]/[DOWN] buttons to set the month, then press [SELECT].
9. Use [UP]/[DOWN] buttons to set the day, then press [SELECT].
10. Use [UP]/[DOWN] buttons to select the display format for days of the week. Press [SELECT] to confirm.
11. Use [UP]/[DOWN] buttons to set the temperature display accuracy (0.1°C or 0.5°C). Press [SELECT] to confirm.
12. Use [UP]/[DOWN] buttons to enable or disable DST (Daylight Saving Time). Press [SELECT] to confirm.

The device software automatically adapts to OpenTherm settings if the thermostat was connected using the OpenTherm connector.

OpenTherm - Domestic Hot Water

1. Press [MENU].
2. Use [UP]/[DOWN] buttons to navigate to the domestic hot water menu, then press [SELECT].
3. Use [UP]/[DOWN] buttons to set the desired temperature, then press [SELECT].
4. The thermostat then returns to the initial screen. Press any key.

The message bar will indicate that domestic hot water is being heated.

Normal Start and Configuration

Follow steps 1 to 17 from the OpenTherm Start-up and Configuration chapter.

CAUTION: Using the [UP] and [DOWN] buttons, you can select TPI (Step 2) or HYSTERESIS (Step 6). Selecting one option excludes the other.

TPI (Time Proportional & Integral)

TPI is an intelligent control algorithm. Setting the TPI type ensures economical system operation due to more accurate temperature maintenance. Besides accurate and stable room temperature, the advantages of this system include limited energy consumption and significant savings. The RT530 offers 3 types of TPI control: 1. for heaters (6CPH); 2. for underfloor heating (3CPH); 3. for electric heating (9CPH).

1. Press [SELECT].
2. Use [UP]/[DOWN] buttons to select the TPI type you want to use.
3. Press [SELECT] to confirm.

Hysteresis

Hysteresis is the difference between the measured temperature and the switching temperature of the connected device (e.g., boiler or pump).

1. Press [MENU].
2. Press [SELECT].
3. Use [UP]/[DOWN] buttons to select the hysteresis value.
4. Press [SELECT] to confirm.

Optimum Start Function

The Optimum Start function is an optional feature that, depending on the room temperature, activates the boiler so that the set temperature is reached according to the schedule. It saves energy by switching off the boiler in the minimum required time.

1. Press [SELECT].
2. Use [UP]/[DOWN] buttons to select [ON] or [OFF].
3. Press [SELECT] to confirm.

Optimum Stop Function

Optimum Stop calculates how long the room will cool down, then switches off the boiler as soon as possible, meaning the system does not operate when it is not needed. If there is a sudden heat loss, the Optimum Stop temperature is compensated by a temperature that ensures comfort.

Boost Mode - Temporary Temperature Change (+Hr)

This function is available in automatic and manual modes. It is used to change the current temperature to another desired temperature for a specified period (up to 9 hours). After this time expires, the thermostat returns to its previous operating mode.

1. Press the [+Hr] button to set a temporary temperature change (e.g., if you want to set a temporary temperature for 4 hours, press it four times), then confirm with the [SELECT] button.
2. Use the [UP] or [DOWN] buttons to select the new temperature and confirm by pressing [SELECT].
3. Press [SELECT] to confirm.

The thermostat display will show the initial screen.

Press the [+Hr] button until "+0" is displayed. Then confirm twice with the [SELECT] button.

Programming - Auto Mode

In this mode, the user can define time schedules for the thermostat (set temperatures for specific time periods). Programmed time schedules should cover all time periods.

1. Press [MENU].
2. Press [SELECT].
3. Use [UP]/[DOWN] buttons to select the program type from:
   • +2 (separate schedule for weekdays and weekend);
   • All days (one schedule for the entire week);
   • Individual (separate schedule for each day of the week).
4. Press [SELECT].
5. Use [UP]/[DOWN] buttons to set the time, then press [SELECT].
6. Use [UP]/[DOWN] buttons to set the minute, then press [SELECT].
7. Use [UP]/[DOWN] buttons to set the temperature, then press [SELECT].
8. Repeat steps for all time periods.

Administrator Settings

Administrator settings are protected by a PIN code. This function allows the administrator to set a service reminder that will prompt the owner about an upcoming boiler inspection.

1. Press [MENU].
2. Use [UP]/[DOWN] buttons to navigate to the ADMIN menu, then press [SELECT].
3. Use [UP]/[DOWN] buttons to enter the PIN code. Press [SELECT] to confirm each digit.
4. Use [UP]/[DOWN] buttons to select the day on which the reminder should appear, then press [SELECT].
5. Use [UP]/[DOWN] buttons to set the desired temperature for the locked thermostat, then press [SELECT].

When service mode is activated, the device locks the temperature set by the installer/owner. To remove the lock, contact the owner and perform a boiler inspection.

RT520TX Thermostat - Pairing with Receiver

In the RT520RF kit, the thermostat and receiver are already factory-paired. During pairing, ensure the thermostat and receiver are at least 1 meter apart.

If the RT520TX and RXRT520 were purchased separately, or if you wish to re-pair the transmitter with the receiver, first ensure the device is disconnected from the power supply and the switches on the receiver are set to AUTO and ON. Connect the receiver to the power source and wait until the red LED lights up. Then, move the switch to the OFF position and then back to the ON position (this must be done quickly, within 2 seconds). A flashing red LED indicates entry into pairing mode.

1. Press [MENU].
2. Use [UP]/[DOWN] buttons to navigate to the SYNCHRO menu, then press [SELECT].
3. Use [UP]/[DOWN] buttons to select PAIR, then press [SELECT].
4. Pairing can take up to 10 minutes.

After successful pairing, the red LED on the receiver will light up.

Testing the connection between thermostat and receiver

1. Press [MENU].
2. Use [UP]/[DOWN] buttons to navigate to the SYNCHRO menu, then press [SELECT].
3. Use [UP]/[DOWN] buttons to select TEST, then press [SELECT].
4. Testing can take up to 10 minutes.

You can now check your settings. If you wish to change them, press UP or DOWN on the relevant screen.

Factory Reset

1. To reset the thermostat, simultaneously hold the [MENU], [DOWN], and [BOOST] buttons for 5 seconds.
2. Administrator settings are not reset.

The device will turn off and then back on.

The red LED and green LED on the receiver will start flashing.