Condensing Boiler Radiant R2KA 24/20 Manual – Complete PDF Guide

The Radiant R2KA 24/20 condensing boiler utilizes the process of condensing the water vapor contained in the exhaust gases to recover heat. This technique greatly increases energy efficiency compared to traditional boilers.

Distinctive features of this boiler include a Storage system that:

• Shortens the delivery time of hot water.
• Ensures better resistance to limescale over time.
• Provides optimal performance even with simultaneous uses of hot water.

However, consider that the storage implies higher gas consumption to maintain temperature and requires specific anti-legionella treatment.

Annual Boiler Maintenance

Annual maintenance is indispensable to preserve the safety, efficiency, and reliability qualities of your device. This annual intervention prevents malfunctions and ensures the continuous safety of the system.

Essential Tips for Your Boiler in Winter

• Pressure Monitoring: Check your Radiant R2KA 24/20 boiler’s pressure gauge to ensure correct pressure.
• Thermostat Batteries: Replace the batteries of the room thermostat to ensure maximum efficiency.
• Heating Pressure Check: Keep the heating system pressure between 1 and 1.5 bar for effective heating.
• Qualified Assistance: Entrust the maintenance and cleaning of your Radiant R2KA 24/20 boiler to expert technicians.

Managing Pressure in the Heating System

Checking the heating system’s pressure every quarter is crucial to ensure it remains between 1bar and 2bar. This check is also fundamental in summer, as the radiator water is used for sanitary water heating. If the pressure drops too low, the boiler may cease to operate.

To adjust the pressure, locate the filling tap under the appliance, usually green, open it until the pressure gauge reaches 1.5bar, then close it.

Boiler Temperature Management

Optimize the performance of your Radiant R2KA 24/20 boiler by correctly adjusting the temperatures. Controlling the heating and domestic hot water (DHW) through the control panel is crucial for energy efficiency and preventing limescale problems.

Details on Temperature Adjustment:

• Heating Temperature Adjustment: Refers to the radiator temperature, not the ambient temperature.
• DHW Adjustment: Set the DHW to the lowest practical temperature to avoid calcifications.

Preventing Limescale in Showers: Filters and Shower Heads

Preventing limescale buildup in shower head aerator filters is crucial for maintaining an efficient sanitary system. Excessive buildup can complicate the removal of aerators and lead to unwanted overheating. We recommend regular replacement of these elements to preserve the functionality of the Radiant R2KA 24/20 boiler.

Preparing Your Boiler for the Holidays

Before leaving for the holidays, it’s essential to take precautions to ensure the safety and efficiency of your Radiant R2KA 24/20 boiler. Even the latest models are not immune to possible leaks.

Here are some recommended measures:

• Close the domestic hot water supply valve to prevent possible water leaks.
• Shut off the gas supply to prevent safety issues.
• Turn off the heat generator to reduce energy consumption and increase safety.

Upon your return, restore all these settings in the reverse order. You will likely need to rearm the heat generator to resolve any ignition errors caused by the shutdown.

These simple actions will allow you to enjoy your holidays with greater peace of mind, knowing that your home and boiler are safe.

The Electronics

Regarding the electronics of this boiler, the control board is provided by NORDGAS, a trusted partner of {manufacturer} for many years. The NORDGAS board is cutting-edge in terms of essential modern boiler systems. Notably, it includes a daily auto-reset system for the board memory, an air venting cycle that starts after refilling the boiler following a water shortage error, and control of thermal shock in heating. {manufacturer}’s board features an exceptional user interface with essential buttons for operation, differentiating it from other boilers with numerous buttons. Error control is precise and easy to read, allowing technicians to receive accurate error information over the phone for an initial diagnosis.

Error Control

The R2KA 24/20 boiler signals all errors through a flashing code on the display, with the main ones being:

• Error 01: No flame, which can occur if the gas tap is closed or if the meter has been changed. Press the button. In all other cases, if it does not restart, call a technician.
• Error 03: Flue side thermal fuse tripped. Press the button. If it does not restart, call a technician.
• Error 04: No water in the system. Refill the system via the black cylindrical tap under the boiler, keep an eye on the pressure gauge above the display, and close the refill tap when the pressure reaches 1.2 or 1.5 bar. The error resets itself, followed by an approximately 2-minute venting procedure. Please wait.
• Error 18: Insufficient circulation. This error may be caused by particularly dirty magnetic filters. Check the magnetic filter at the boiler inlet with a technician to restore the circulator flow rate.

Notifications

These refer not to errors but to functions currently in operation:

• F08 Anti-freeze function for heating active: If the boiler is external and reaches a very low temperature, this procedure activates to prevent the technical water from freezing. Please wait for the operation to complete.
• F33 System Venting Cycle: This usually happens during the reset of error E04. Once the {manufacturer} R2KA 24/20 boiler pressure is restored, it performs this function for about 2 minutes. Please wait for the operation to complete.
• FH Fast H20: The boiler is preparing to preheat the sanitary water. Please wait for the procedure to complete.

Energy Efficiency and Quietness

{manufacturer} has revolutionized energy efficiency with its boiler series, offering exceptional performance in terms of both gas and electricity consumption. These models, besides being extraordinarily quiet (about 55 decibels), boast reduced gas consumption, thanks to their 9 flame modulations and proportional temperature control. Electrical consumption is also minimized, thanks to the modulating WILO circulator and optimized standby consumption.

General Usage Information

To maintain the safety, efficiency, reliability, and performance characteristics that distinguish the device, it is necessary to perform annual maintenance. Annual maintenance is essential for the safety and continuous use of the R2KA 24/20 device.

Regarding the Use of Electric Energy

• Do not touch the appliance with wet or damp parts, or while barefoot
• Do not pull on electrical cords
• Do not expose the appliance to atmospheric agents such as rain, sun, etc., unless expressly provided for.
• In case of damage to the cord, turn off the appliance and consult exclusively professionally qualified personnel for its replacement.

In Case of Gas Odor

• Do not operate electrical switches, the phone, or any other device that may generate electrical discharges or sparks.
• Immediately open doors and windows to create an air exchange that can quickly clear the room.
• Close the gas taps.
• Request the immediate intervention of professionally qualified personnel.

Information on Components and Spare Parts

Here is an informative resource that covers a wide range of components and spare parts for the R2KA 24/20 boiler. Each element is described in detail to help you better understand its role within the appliance and how to maintain it optimally.

Temperature Adjustment

On the control panel of the Radiant R2KA 24/20 condensing boiler, you can find all the operational information. You can set the temperatures for heating or hot water by pressing the + and – buttons next to their respective symbols: Faucet and Radiator. After pressing, the boiler displays the set temperature for only a few seconds.

Normally, the boiler shows the flow temperature, to be interpreted as the internal temperature of the boiler. As a result, you will see the temperature rise even in summer when the Radiant R2KA 24/20 boiler produces hot water, while in winter it can be interpreted as the current temperature of the radiators.

Using the + and – buttons at the top for heating and at the bottom for domestic hot water, you can choose the desired temperatures for heating. We suggest:

• From 25°C to 38°C if you have underfloor heating.
• From 55°C to 65°C if you have radiators made of aluminum or steel.
• From 45°C to 60°C if you have cast iron radiators.

For domestic hot water, you can choose the temperature using the + and – buttons at the bottom. We suggest a temperature between 38 and 45°C.

The general advice for the temperature of domestic hot water is to keep it as low as possible, especially if your water supply provides very hard water (over 30°F).

Durability and Efficiency of the 20-Liter Stainless Steel Boiler

The 20-liter stainless steel boiler, an integral part of the {manufacturer} R2KA 24/20 boiler, has been developed to maximize efficiency in hot water production. Its internal coil ensures excellent heat exchange and uniform water heating.

To maintain these performances over time, regular maintenance is crucial, particularly the replacement of the sacrificial anode to prevent corrosion. Caring for this element is essential to ensure the longevity and efficiency of the boiler.

Neglecting to replace the anode could lead to premature deterioration of the boiler, with risks of leaks and inefficiencies. Therefore, it is important to adhere to the manufacturer’s maintenance recommendations and regularly monitor the condition of the anode.

Technological Innovation: The Modulating Pump for Boilers

The latest generation modulating pump, with adjustable speed from 0 to 100%, represents a qualitative leap in the efficiency of modern boilers. Managed by a sophisticated electronic system with a dedicated control connector, this pump enables optimization of energy consumption and reduction of management costs. Its ability to dynamically adapt to the system’s needs not only ensures optimal performance but is also a fundamental requirement in new installations, highlighting the importance of this technology for a more sustainable and economical future.

Automatic Plastic Air Purger

The plastic automatic air purger, used as an insert in the purging housing in the pump manifold, is a key component in the Radiant R2KA 24/20 boiler. This small element plays a vital role in ensuring the efficiency of the heating system by eliminating air from the system.

Made of durable plastic, this air purger is designed to easily fit into the dedicated housing in the pump manifold. Its use is particularly recommended to prevent air accumulation in the boiler’s hydraulic circuitry, especially in systems with a lot of aluminum where this problem is more frequent after periods of inactivity (summer).

Regularly checking and replacing the air purger and the system pressure is essential for maintaining uninterrupted operation at the start of the heating season. Its functionality is crucial for the proper operation of the entire domestic heating system.

3/8 Automatic Air Purger

The 3/8 automatic air purger is a fundamental component in the Radiant R2KA 24/20 boiler to ensure the elimination of air in the heating system. This small but essential device plays a critical role in maintaining the efficiency of the heating system.

Despite its low cost, this component is vital to ensure that there is no trapped air in the radiator system, especially for aluminum ones, where the presence of air can be a frequent problem, particularly after long periods of inactivity like during the summer.

Checking the functionality and replacing the air purger is always advised to prevent circulation problems at the beginning of the heating season. Its efficiency is crucial for the proper operation of the entire domestic heating system.

Safety Systems according to the ErP Directive

The construction and installation of boilers in Europe are strictly regulated by a series of European standards, aimed at ensuring safety, energy efficiency, and reduction of environmental impact.

One of the main reference regulations is the ErP (Energy-related Products) Directive, which imposes stringent requirements in terms of energy efficiency and emissions for all energy-related products, including boilers. This directive is accompanied by specific UNI EN standards for each type of boiler, detailing the technical and safety standards to be respected.

The R2KA 24/20 boiler therefore includes:

The Safety Thermostat, located on the heating supply, intervenes by blocking the gas flow to the burner in case of overheating of the water in the primary circuit. It is essential to never deactivate this safety device.

The Flame Ionization Detector ensures safety by shutting down the boiler in case of gas absence or incomplete ignition of the main burner.

The Antifreeze Device activates the burner to maintain the water temperature above 5 °C, preventing freezing of the system.

The Hydraulic Safety Valve, set at 3 bar, protects the heating circuit. It is advisable to connect it to a siphoned drain and not use it to empty the circuit.

Possible Improvement Works

The condensing boiler Radiant R2KA 24/20 requires special attention to the correct installation of the flue pipe. Especially in horizontal sections, condensation can form, compromising the functionality of the fan. It is not uncommon to see installations where the flue pipe (especially if corrugated) forms a siphon, causing the boiler to produce very loud noises. It is essential to have a qualified technician ensure that the pipes are in optimal condition.

Integrating a Gas Tap with a Test Well

Not always does the meter provide a connection for instrumental tightness testing. A useful tip is to replace the gas tap under the boiler with a valve with a well equipped with an instrumental take-off, essential for the tightness test of the system. This element can be crucial in case of inspections and safety checks and certainly facilitates the maintenance of the R2KA 24/20 boiler.

In fact, during the maintenance of the appliance, it is mandatory to perform a suitable test like UNI 11137:2019 that verifies the correct tightness of the gas system.

Flushing the Heating System

Flushing the heating system is crucial to prevent clogging of the primary exchanger of the Radiant R2KA 24/20 boiler. Over time, especially in cast iron or aluminum systems, a metallic sludge can form that can clog the narrow passages of the exchanger.

After flushing the system, it is highly recommended to install a magnetic sludge filter on the Radiant R2KA 24/20 boiler. This filter plays an essential role in protecting the exchanger from the buildup of dirt and debris, ensuring greater efficiency and longevity of the heating system.

Additional improvements can include the installation of an advanced thermostat with relay function. This device allows for more effective management of heating hours, helping to optimize energy consumption.

Suggested Accessories

To optimize the functionality and efficiency of your R2KA 24/20 boiler, there are various accessories that we recommend considering:

• Programmable Thermostat: Regulates ambient temperature on a daily or weekly basis. The advanced new generation models also offer remote control and advanced programming.
• Magnetic Filter Dirt Separator: An essential device for keeping the hydraulic circuit clean, removing both magnetic and non-magnetic impurities and debris.

Magnetic Filter for Heating

Considered the best accessory to block the entry of dust and debris from the heating system into the device.

The decision to install a magnetic filter on the heating return line is an important one to maintain the effectiveness and reliability of the boiler. This component is essential for filtering debris that could otherwise accumulate and hinder the proper functioning of the boiler, particularly regarding the primary exchanger and the diverter valve. It’s important to choose a high-quality filter and ensure it is correctly installed to fully benefit from its advantages.

Choosing a Polyphosphate Doser

For hard waters exceeding 20 French degrees, we recommend the use of a polyphosphate doser for the Radiant R2KA 24/20 boiler.

These devices mix polyphosphates, either in powder or liquid form, with the incoming water, minimizing limescale formation in the Radiant R2KA 24/20 boiler. The choice of the right doser depends on the specific needs of the system and the type of water.

Polyphosphates are primarily available in two forms:

• Powder Polyphosphates
• Liquid Polyphosphates

The selection of the polyphosphate influences the type of mixing device required.

Integrated Solutions: Thermostat and Programmable Thermostat

For advanced and integrated control of the Radiant R2KA 24/20 boiler, choose a latest generation room thermostat or programmable thermostat.

These devices offer sophisticated home temperature regulation, perfectly adapting to your lifestyle and needs. With programmable thermostats, you can easily set custom schedules for each day of the week, ensuring a consistently comfortable environment and optimizing energy consumption.

Select from a variety of models, including:

• Daily Programmable Thermostats
• Weekly Programmable Thermostats
• Connected Thermostats for Remote Control

Your choice should complement the specifics of your Radiant R2KA 24/20 boiler and your home.

Daily Environmental Thermostat: Regulatory Compliance and Economy

The daily environmental thermostat is the ideal solution for complying with regulations requiring at least two temperature levels within 24 hours, combining efficiency and simplicity.

This device ensures the ability to set different temperature levels throughout the day, perfectly adapting to various needs and contributing to energy savings. Its ease of use makes it suitable for all ages, including seniors.

• Flexible programming and compliance with regulations
• Easy to use for all age groups
• Affordable cost and great added value

An economical and functional option for those looking for effective home temperature control without complexity.

Weekly Programmable Thermostat

For advanced and personalized home temperature management, the weekly programmable thermostat is an excellent choice.

This device allows for setting different temperatures for various days of the week, perfectly adapting to different weekly routines. It is ideal for those who need detailed heating control, with the ability to set lower temperatures on days when the home is empty and higher when it is occupied.

Key features of the weekly programmable thermostat include:

• Flexible programming for each day of the week
• Advanced energy-saving functions
• Intuitive user interface for easy programming

A weekly programmable thermostat is perfect for those seeking a balance between comfort, convenience, and energy efficiency, providing precise control of the home climate.

Advanced New Generation Thermostats

New generation advanced thermostats offer cutting-edge technologies for optimal home climate control.

These devices stand out for their learning capability and adaptation to user habits, automatically adjusting the temperature based on daily and seasonal patterns. With features like remote control via smartphone and integration with home automation systems, they offer an unprecedented level of convenience and energy efficiency.

Salient features of these thermostats include:

• Wi-Fi connectivity and remote control
• Integration with voice assistants and smart home systems
• Learning algorithms for automatic temperature optimization

For those seeking the utmost efficiency, convenience, and personalization in home temperature control, an advanced new generation thermostat is the ideal choice.

Magnesium Anode for Boiler

The magnesium anode is a critical component for combating corrosion in the Radiant R2KA 24/20 boiler’s accumulation tank. Its high reactivity helps to preserve the boiler’s metal parts from oxidation, enhancing durability and efficiency.

Periodic replacement of the magnesium anode is vital, and should be tailored based on the boiler’s use and water quality.

Issues Related to the Magnesium Anode

In certain cases, especially under the influence of strong electrical fields:

• The magnesium anode can degrade rapidly.
• Rapid degradation can cause excessive air release in the system, noticeable after periods of non-use.
• A sulfur odor may develop if the boiler remains inactive for several months.

Air-related problems usually subside after the first few weeks of maintenance. An aluminum anode for future maintenance may be considered for its longer lifespan.

INFO MENU DISPLAY DATA

To view the boiler data from info menu you just have to press the INFO key. The info code will be displayed on the left side of the screen and its relative value will be displayed on the centre of the screen.
Use keys ‘ + ’ and ‘ – ’ of the heating circuit to scroll through the list of displayed data. To exit display mode press the INFO ‘ i ’ key.

Anomaly Reporting Codes R2KA 24/20

To display the last 5 anomaly reporting codes, from the most recent in chronological order, activate OFF mode using the central button and hold down the INFO button for 5 seconds. To scroll through the list of stored anomalies, use the PLUS and MINUS buttons of the heating system. To reset the anomaly history, press the RESET button. To exit the display environment, press the INFO button.

Common Questions and Answers About the Boiler

Here is a list of common questions and answers that we frequently receive about the Radiant R2KA 24/20 boiler model. This section will help you better understand the features, functionality, and maintenance of your appliance.

Hot Water takes forever to reach the shower/bathroom !!

The delay in hot water reaching the bathroom is often caused by a buildup of dirt in the aerator or showerhead holes. This buildup can reduce water flow, consequently slowing down the flow of hot water in the pipes. Cleaning these accessories from limescale can usually restore the speed of the hot water arrival.

Additionally, if the pipes connecting the bathroom to the boiler are made of iron, they might absorb some of the water’s heat, lengthening the time for hot water to arrive. The presence of iron pipes can thus affect the timing of hot water delivery to the bathroom.

Loud Noises During Operation

If your Radiant R2KA 24/20 boiler makes loud noises during operation, first check the system pressure. Too low a pressure can be the cause. Otherwise, in this condensing boiler, it could occur due to lack of maintenance.

Indeed, the heat exchanger tends to slightly oxidize during operation and over time a large amount of dirt can accumulate in the condensate siphon. Regular maintenance is essential to reduce the risk of noises or machine shutdowns.

Boiler Compatibility with Opentherm

YES: The boiler’s thermostat connections are configured for a non-powered interface, allowing connection to a Smart Thermostat or Remote Control. The possibilities offered include:

• Adjustment of domestic hot water temperature: Particularly beneficial when the R2KA 24/20 boiler is located in less accessible places like the attic or an external technical room.
• Adjustment of radiator temperature: The advanced Opentherm chronothermostat allows communication with the boiler to regulate radiator temperatures in addition to room temperature.
• Time scheduling for domestic hot water: Ideal for boilers with storage tanks, it enables optimization of boiler maintenance costs, such as gas consumption.
• Diagnostics and Error Management: With the Opentherm 2 protocol or via a specific remote control from Radiant.
• etc…

Pressing the buttons to adjust the heating, the temperature does not change.

The button panel is sensitive to repeated presses after years of operation. Often, the malfunction of the adjustment buttons is due to the absence of a thermostat, which has led to the exclusive use of the boiler’s buttons.

In light of this, it is suggested to install a new control board to restore the correct functioning of the button panel, but also to integrate a thermostat to continue adjusting the heating from another, more reliable, and less expensive device.

Downloadable Manuals

• Technical Manual for Radiant R2KA 24/20 Boiler