Condensing Boiler Radiant R2K 28 Manual – Complete PDF Guide

The condensation technology used by the boiler Radiant R2K 28 allows the recovery of latent heat from the water vapor in the combustion fumes. This process ensures greater energy efficiency compared to conventional boilers.

Traditional boilers do not fully exploit the sensible heat of the fumes to avoid corrosion caused by condensation. Thus, the water vapor produced in combustion is released into the atmosphere, dissipating precious heat. Condensing boilers, on the other hand, effectively use this heat, significantly reducing energy consumption. Replacing an old boiler with a condensing one can lead to energy savings of up to 20%.

Annual Maintenance

Annual checks are crucial to ensure optimal boiler performance, maintaining efficiency, safety, and reliability. These annual checks are fundamental to ensure the safety and ongoing effectiveness of the device.

Essential Tips for Your Boiler in Winter

• Pressure Monitoring: Check your Radiant R2K 28 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 R2K 28 boiler to expert technicians.

Maintaining Heating System Pressure

It’s essential to check the heating system’s pressure quarterly, ensuring it’s between 1bar and 2bar. This check should not be neglected even during the summer months, as the radiator water is used for hot water production. A drop in pressure can interrupt the boiler’s operation.

To adjust the pressure, use the filling tap under the appliance. Open it to bring the pressure to 1.5bar, then close it.

Effective Temperature Settings

To make the most of your Radiant R2K 28 boiler, it’s crucial to understand how to effectively adjust the temperatures. This not only optimizes home comfort but also helps prevent limescale accumulation.

Focus on Temperature Adjustment:

• Heating Temperature: Be careful to adjust the radiator temperature, not the ambient temperature.
• DHW Temperature: A lower DHW temperature reduces the risk of calcification.

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 R2K 28 boiler.

Boiler Safety During the Holidays

It’s crucial to take some precautions with your Radiant R2K 28 boiler before leaving for the holidays to prevent accidents and problems. This also applies to the latest generation boilers.

Preventive actions:

• Close the main water tap to avoid unexpected leaks.
• Shut off the gas to increase the safety of your home.
• Turn off the heat generator to limit unnecessary energy consumption.

Once you return, reactivate the settings by following the steps in reverse. You might need to restart the heat generator to cancel the shutdown errors.

With these simple steps, you can enjoy your vacation without worries, knowing that your boiler is safe and well managed.

Hot Water Production

The R2K rapid instant model boiler features a flow meter to detect the opening of the hot water tap, hence the demand for sanitary water. Thanks to the first of nine available modulations, the boiler can provide water at the set temperature even at very low flow rates. Essentially, we can set a sanitary water temperature of 38 degrees and slightly open the tap. The boiler’s flow meter will detect the sanitary demand and maintain the temperature precisely at 38 degrees. This feature is crucial for boilers installed in high-rise buildings where water pressure may not be sufficient to activate older boilers.

The FAST-H2O Function

This precision in sanitary water production is consistently ensured by the recently mentioned concentric coil. The technical heating water, when producing sanitary water, circulates only inside the boiler, allowing for better temperature control. The pre-production system for hot water, using this technology to mimic a boiler with a tank, is called FAST-H2O. It preheats the sanitary water in the heat exchanger to provide it immediately to the user upon request. The heat exchanger already contains a quantity of water that can be dispatched directly to the tap.

• More immediate delivery of sanitary water
• Eliminating unnecessary waiting, increasing user comfort
• Limiting the waste of water while waiting for it to heat up

To activate this function, press the and buttons on the Sanitary control panel.

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 {name} 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} {name} 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.

Noise and Consumption

Lastly, regarding noise and performance in gas and electricity consumption. {manufacturer} has designed this series of boilers to be particularly quiet, operating as silently as a whisper (about 55 decibels). The quietness is thanks to the MOPLEX muffler at the air inlet to the fan, as well as the soft panel glued to the front panel that perfectly seals the combustion chamber. The result is a very quiet boiler. Regarding gas consumption, we have a very low rate thanks to the 9 flame modulations and proportional temperature control. Electricity consumption is also low, thanks to the use of a modulating WILO circulator and a careful strategy of turning off non-essential devices in standby mode.

Boiler Safety and Maintenance

It is important to subject the R2K 28 boiler to annual maintenance to ensure its efficiency and safety. Interventions on the boiler by unqualified people are strongly discouraged, as they can compromise the safety of the appliance. For any problem or anomaly, it is essential to turn to an expert technician. Remember that periodic maintenance by professionals is crucial for the longevity and safety of the appliance.

Safety in the Use of Electric Energy

It is essential to adopt precautions when using the R2K 28 boiler to avoid risks:

• Do not handle the appliance with wet or damp hands, nor walk barefoot in its vicinity.
• Handle electrical cords carefully to avoid damage and malfunctions.
• Do not leave the appliance outdoors exposed to rain or sun, unless it is specifically designed for this purpose.
• If the cord is damaged, immediately turn off the appliance and contact a qualified technician.

Remember that only authorized personnel should install and maintain the appliance. Unauthorized maintenance or improper use can invalidate the warranty and compromise safety.

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 R2K 28 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.

Information on Components and Spare Parts

Here is an informative resource that covers a wide range of components and spare parts for the R2K 28 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 R2K 28 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 R2K 28 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).

The Patented {manufacturer} Heat Exchanger

The heat exchanger is our star player. {manufacturer} has created it with a concentric coil that combines both sanitary water heating and heating system, significantly lowering the exchanger temperature and leading to optimal condensation. One might think this exchanger resembles older models from other companies, like the bi-thermal exchanger that caused us several issues with hard water in Modena. However, this new class of exchanger, with the sanitary piping inside the coil, gradually heats the water, thus reducing lime scale formation.

Another important note about lime scale formation, as already highlighted by {manufacturer}, is that the piping of the {name} boiler is designed to facilitate vibration of the sanitary water pipe, useful in scraping off the thin lime scale deposits that form over time.

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 R2K 28 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 R2K 28 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 R2K 28 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 R2K 28 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 R2K 28 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 R2K 28 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 R2K 28 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 R2K 28 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 should be applied on the heating return line to the boiler, separating everything that could clog the boiler and cause temperature increases in the primary exchanger. The diverter valve is also less stressed, and the adoption of the magnetic filter could prevent its leakage.

Polyphosphate Dosing Pump

If the hardness of the tap water exceeds 20 French degrees, we suggest equipping the Radiant R2K 28 boiler with a polyphosphate doser.

Polyphosphates, available in powder or liquid form, are mixed with the cold water entering the Radiant R2K 28 boiler, significantly reducing limescale formation. These additives are essential for maintaining efficiency and extending the lifespan of the device and must be regularly replenished.

There are several models of polyphosphate dosers, the most common ones are:

• Powder Polyphosphates
• Liquid Polyphosphates

Each type of polyphosphate requires a specific system for mixing.

Room Thermostat and Programmable Thermostat

For optimal temperature control in your home, consider installing a thermostat or programmable thermostat for your boiler.

These devices allow you to regulate and program the temperature precisely, adjusting it to your daily needs. A programmable thermostat, in particular, offers the possibility to set different programs for specific days and times, optimizing comfort and reducing energy costs.

There are various models available, including:

• Daily Programmable Thermostats
• Weekly Programmable Thermostats
• New Generation Thermostats with Remote Control

The choice of model depends on your specific needs and the configuration of your heating system.

Daily Environmental Thermostat for Seniors

The daily environmental thermostat is particularly suitable for seniors, offering simple and immediate regulation of home temperature.

This device is ideal for those who desire an intuitive and uncomplicated control. Its daily programming allows for easy temperature adjustment to daily needs, making it particularly suitable for those who require a simple and reliable solution.

• Simple and clear user interface
• Easy temperature regulation
• Compliant with energy efficiency regulations

The daily thermostat is an economical and functional solution, ideal for those needing direct and easy heating control.

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.

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 R2K 28

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.

Useful Tips and FAQ

We have gathered a series of useful tips and answers to the most frequent questions to help you maximize the efficiency and lifespan of your Radiant R2K 28 boiler. Find out everything you need to know for its best management.

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 R2K 28 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.

Opentherm Protocol Support by the Boiler

YES: The boiler is pre-equipped for a tension-free connection with an Advanced Thermostat or Remote Control. The functionalities offered include:

• Control of domestic hot water temperature: Useful for R2K 28 boilers installed in less accessible locations.
• Adjustment of radiator temperature: An advanced Opentherm chronothermostat allows communication of the desired radiator temperatures to the boiler.
• Time scheduling for water heating: Beneficial for boilers with storage tanks, helping to reduce boiler maintenance costs, like gas.
• Error Resolution: Through Opentherm 2 or with devices 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

• Radiant R2K 28 Condensing Boiler Manual