Condensing Boiler Radiant R2KA 24/8 Manual – Complete PDF Guide

In the Radiant R2KA 24/8 condensing boiler, the condensation of vapor in the exhaust gases occurs, a process that recovers heat and improves energy efficiency compared to standard boilers.

This boiler is also equipped with a Storage system that:

• Decreases the wait for hot water at the faucets.
• Offers greater long-term resistance to limescale.
• Operates efficiently when drawing hot water from multiple sources simultaneously.

However, the storage system leads to increased gas consumption for temperature maintenance and requires checks for legionella prevention.

Common Procedures

To maintain the safety, efficiency, reliability, and performance characteristics that distinguish the device, it is necessary to perform maintenance annually. Annual maintenance is essential for safety and continuity of operation.

Winter Boiler Maintenance: Complete Guide

• Pressure Check: Ensure that your Radiant R2KA 24/8 boiler’s pressure gauge shows adequate pressure.
• Thermostat Maintenance: Regularly check the thermostat batteries to avoid malfunctions during the colder months.
• Heating System Pressure: Check that the pressure is maintained between 1 and 1.5 bar for optimal operation.
• Professional Support: For thorough maintenance and cleaning of your Radiant R2KA 24/8 boiler, always contact qualified personnel.

Check the Heating System’s Pressure

At least every quarter, ensure that the system’s pressure is correct; it should be between 1bar and 2bar. Also check this in the summer, as the boiler uses radiator water (only in internal circulation) to heat domestic hot water. If the pressure is low, the boiler is equipped with a component that stops the production of heating or hot water.

Remember to use the filling tap, found under the appliance. Open it and check that the pressure gauge reaches 1.5bar, then close it.

Boiler Temperature Management

Optimize the performance of your Radiant R2KA 24/8 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.

Regular Maintenance for Shower Heads and Shower Aerator Filters

Periodic maintenance of shower heads and aerator filters is essential to prevent limescale buildup. The obstruction caused by limescale makes it difficult to remove the aerators and affects water temperature, causing intermittent operation of the Radiant R2KA 24/8 boiler. Follow our guide to replace these components when necessary.

Getting Your Boiler Ready for Vacation

Before leaving for a vacation, it’s vital to ensure that your Radiant R2KA 24/8 boiler is ready and safe. This is important even for the most advanced boiler models.

Recommended procedure:

• Stop the hot water supply to prevent leaks.
• Shut off the gas supply as a safety precaution.
• Deactivate the heat generator to avoid wasting energy and increase safety.

Upon your return, restore the functions in reverse order. You may need to restart the heat generator to resolve errors related to the prolonged shutdown.

By following these steps, you can relax on vacation knowing that your boiler is in a safe state.

Maintenance and Assistance Made Easy

The R2KA 24/8 boiler makes maintenance a straightforward process. The user interface, developed in collaboration with NORDGAS, allows for quick identification of any issue thanks to a well-structured error reporting system. The boiler is designed to facilitate daily maintenance operations and remote diagnosis.

Easy Diagnosis and Error Resolution

Common problems like no flame, thermal fuse interruption, or lack of water are easily identifiable thanks to clear error codes displayed on the panel. This enables a quick response and, if necessary, efficient technical intervention. Additionally, features such as the anti-freeze and the FAST-H2O system ensure stable operation and reduce the frequency of maintenance.

• 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 24/8 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.

Comfort and Sustainability in Noise and Consumption

The {manufacturer} boiler series is designed with user comfort and environmental sustainability in mind. Their ultra-quiet operation, with noise levels of only 55 decibels, ensures unparalleled tranquility at home. From a sustainability perspective, these boilers excel in reducing gas and electricity consumption, with their 9 flame modulations for precise temperature control and the use of a high-efficiency modulating circulator. This combination of technologies makes {manufacturer}’s boilers an ideal choice for those seeking an eco-friendly and comfortable option.

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 24/8 device.

Safety Regulations for Electric Energy

Safety in the use of the R2KA 24/8 boiler requires adherence to specific rules:

• Avoid contact with the appliance in the presence of moisture or while barefoot.
• Do not force or pull electrical cords, to prevent risks of short circuit or damage.
• Protect the appliance from atmospheric agents if not specifically indicated for outdoor use.
• In case of faults in the cord, stop using and rely on a specialized technician for repairs.

It is also important that any installation, initial ignition, and maintenance is carried out by qualified and authorized technicians to ensure proper functioning and compliance with the warranty. Use not in accordance with the instructions can be dangerous and invalidate the manufacturer’s liability.

Procedure in Case of Gas Leak

In the event of a suspected gas leak, it is essential to follow these instructions to ensure safety:

• Avoid operating electrical switches or devices that may create sparks.
• Open doors and windows to ventilate the area and disperse the gas.
• Immediately close the gas taps to prevent further leakage.
• Contact a qualified technician without delay for emergency intervention.

The R2KA 24/8 boiler must be used only as intended: to heat water without bringing it to a boil. Any other use is improper and dangerous. Moreover, installation and maintenance must be carried out exclusively by authorized personnel to ensure safety and regulatory compliance.

Guide to Components and Spare Parts

This section is dedicated to providing a complete overview of the various components and spare parts available for the R2KA 24/8 boiler. You will find detailed information on each part, from its main function to advice on when it might need to be replaced.

Temperature Adjustment

On the control panel of the Radiant R2KA 24/8 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 24/8 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).

Innovation and Sustainability in the 8-Liter Micro-Storage Boiler

The 8-liter Micro-Storage Boiler is at the forefront of water heating technology, ideal for those seeking a quick and eco-friendly solution. This boiler, used for sanitary preheating, combines technological innovation with sustainability.

The ability to choose between different types of anodes, including electronic ones that reduce maintenance frequency, exemplifies this boiler’s design with the environment in mind. Regular cleaning prevents limescale accumulation, preserving efficiency over time.

With its 8-liter storage capacity, it surpasses the limitations of traditional plate exchangers in terms of capacity and limescale resistance, making it a sustainable choice for hot water supply.

Superior Efficiency with the Variable Speed Modulating Pump

Variable speed modulating pumps, now standard in the latest generation boilers, are designed to operate in a range from 0 to 100%, regulated by an advanced electronic control system. These pumps stand out for their energy efficiency, reducing costs and promoting responsible resource use. The ability of these pumps to adapt to the varying needs of the system, precisely regulating speed, results in a more efficient and environmentally friendly heating system. Current legislation emphasizes the importance of these pumps, making them an essential element in new boiler installations for greater sustainability.

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 24/8 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 24/8 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 24/8 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 24/8 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 24/8 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 24/8 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 24/8 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.

Innovative Accessories

Enhance the functionality of your R2KA 24/8 boiler with these cutting-edge accessories:

• Advanced Programmable Thermostat: Control the temperature of your home with intelligent solutions that offer flexible programming and interactivity.
• Magnetic Filter Dirt Separator: An indispensable accessory for maintaining the efficiency and cleanliness of your boiler’s hydraulic circuit.

Magnetic Filter for Heating

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

The magnetic filter, installed on the heating return line to the boiler, is essential for maintaining system efficiency. It retains harmful elements like dust and debris, preventing boiler blockage and reducing the risk of overheating the primary exchanger. Additionally, it helps to reduce pressure on the diverter valve, thus increasing its lifespan and reducing the chances of leaks.

Choosing a Polyphosphate Doser

For hard waters exceeding 20 French degrees, we recommend the use of a polyphosphate doser for the Radiant R2KA 24/8 boiler.

These devices mix polyphosphates, either in powder or liquid form, with the incoming water, minimizing limescale formation in the Radiant R2KA 24/8 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.

Thermostat and Programmable Thermostat

Maximize comfort and efficiency of your Radiant R2KA 24/8 boiler by installing a room thermostat or programmable thermostat.

These smart devices allow you to customize your home’s temperature, ensuring a pleasant environment and reducing energy consumption. Particularly, programmable thermostats allow you to set different temperature settings for each day of the week or specific times of the day.

Available models include:

• Daily Programmable Thermostats
• Weekly Programmable Thermostats
• Smart Thermostats with Remote Control

Choose the model that best meets the needs of your home and your Radiant R2KA 24/8 boiler.

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

The magnesium anode is an essential component for corrosion protection in the Radiant R2KA 24/8 boiler’s accumulation tank. Its high reactivity prevents the oxidation of the boiler’s metal parts, extending efficiency and longevity.

Regular replacement of the magnesium anode is crucial and depends on the conditions of use and water quality.

Considerations on the Magnesium Anode

In certain circumstances, especially due to strong electrical fields:

• The magnesium anode may wear out rapidly.
• Excessive consumption can cause air buildup in the system, evident when opening the tap after periods of non-use.
• A sulfur smell may develop after months of boiler inactivity.

Generally, issues related to air buildup diminish after the first few weeks of maintenance. An aluminum anode used in subsequent maintenance can offer a longer-term solution and greater durability.

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 24/8

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 24/8 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 24/8 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 24/8 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 24/8 Boiler