The Euroterm MAIA PLUS D 24 S sealed boiler is a boiler in which balanced combustion is achieved through a fume fan, also known as an extractor. It has lower energy efficiency compared to a condensing boiler, however, all combustion is controlled inside an enclosure called the combustion chamber.

In fact, traditional boilers cannot exploit all sensible heat to avoid corrosion from condensation. The water vapor generated by the combustion process is then released into the atmosphere through the chimney, along with the associated latent heat.

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.

Essential Tips for Your Boiler in Winter

  • Pressure Monitoring: Check your Euroterm MAIA PLUS D 24 S 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 Euroterm MAIA PLUS D 24 S 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.

Optimal Temperature Settings for the Boiler

The Euroterm MAIA PLUS D 24 S boiler offers flexibility in adjusting temperatures for domestic heating and hot water. Use the control panel to find the ideal temperature, keeping in mind the importance of setting the DHW to the minimum necessary to reduce the risk of calcification.

Tips for Adjusting Temperatures:

  • Radiator Temperature: The adjustment refers to the radiator temperature, not the ambient temperature.
  • DHW Temperature: Keep the domestic hot water temperature as low as possible to prevent calcification in the secondary heat exchanger.

DIY: Replacement of Shower Filters and Heads

Discover how to easily replace the aerator filters and shower heads in your shower to prevent limescale buildup. This simple maintenance can avoid overheating problems and difficulties in removing filters, ensuring the proper functioning of the Euroterm MAIA PLUS D 24 S boiler.

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Boiler Settings for the Holidays

Before going on vacation, it is important to take some measures to ensure the safety of your Euroterm MAIA PLUS D 24 S boiler. Even the most modern models can have problems if left inactive for an extended period.

Recommended steps:

  • Close the water valve to avoid leaks during your absence.
  • Disconnect the gas supply as an additional safety measure.
  • Turn off the heat generator to conserve energy and improve safety.

When you return, reactivate these settings in reverse order. You may need to reset the heat generator to correct any errors.

These simple steps will ensure a worry-free vacation, knowing that your boiler is safe.

Maintenance Tips

Regular maintenance of the MAIA PLUS D 24 S boiler is crucial to preserve its efficiency and safety. It is strongly advised against for inexperienced users to attempt any technical intervention on the boiler. Any doubts or anomalies in operation must be immediately reported to an expert technician. Annual maintenance, carried out by qualified technicians, is fundamental for the correct operation of the appliance.

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.

Safety Actions in Case of Gas Detection

If a gas odor is detected, it is fundamental to adopt these precautionary measures:

  • Do not use electrical appliances, including phones, that might generate sparks.
  • Immediately open doors and windows to facilitate air exchange.
  • Stop the gas supply by closing the taps.
  • Immediately request the intervention of a specialized technician.

It is important to use the MAIA PLUS D 24 S boiler exclusively for the purposes for which it is designed, avoiding improper uses that can be dangerous. Ensure that any intervention on the boiler is carried out by qualified personnel to prevent accidents and maintain the warranty.

List of Components and Spare Parts

In this guide, you will discover everything there is to know about the different components and spare parts of the MAIA PLUS D 24 S boiler: how to identify them, their specific function, and useful tips for maintenance and replacement.

Boiler MAIA PLUS D 24 S Display Interface

Boiler MAIA PLUS D 24 S Display Interface

The MAIA PLUS D 24 S boiler's display is designed to provide all essential information in a clear and accessible manner. Let's look at the details:

  • PLUS and MINUS Thermo: Increase and decrease the radiator temperature (independent of ambient temperature).
  • ECO/COMFORT: Select between ECO/COMFORT1/COMFORT2 modes for water heating.
  • RESET: Resets errors (except water shortage) and accesses the menu with prolonged pressure.
  • SUN/SNOWFLAKE: Switch between Summer/Winter modes.

Display symbols and indications:

  • SUN/SNOWFLAKE: Indicates the boiler's seasonal mode.
  • ECO/COMFORT: Status of the domestic hot water mode.
  • 1.2 bar: Current pressure level of the boiler.
  • Drop Symbol: Symbol representing the flame's power, varies in size.
  • Upper Temperature: Temperature of the primary circuit, also observable during DHW production.
  • Lower Temperature: Current temperature of the sanitary water.

ACS Production Configurations in the Boiler

The boiler offers various options for producing domestic hot water (DHW), thanks to the integration of micro-accumulation and the COMFORT mode, available from the control panel. Modes include ECO, COMFORT1, and COMFORT2.

Details of ECO Mode

In ECO mode, the boiler activates DHW production on demand. With the opening of a tap, the boiler starts up, regulating the flame based on water flow for precise temperature control. However, the wait for hot water can be prolonged due to micro-accumulation.

Details of COMFORT Mode

COMFORT mode, in both its variants, offers preheating of DHW. COMFORT1 allows for manual temperature adjustment, while COMFORT2 maintains a stable temperature at 45 degrees.

Temperature Adjustment

On the control panel of the Euroterm MAIA PLUS D 24 S 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 Euroterm MAIA PLUS D 24 S 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).

Common Errors

  • Error A01: Flame Lock. This error can occur following the replacement of the gas meter. A reset can be performed by pressing the R button. If the problem persists, contact support.
  • Error F37: Lack of Water. Check the pressure gauge: if the pressure is below 0.8 bar, this error occurs. To resolve it, open the filling tap to bring the pressure to about 1.5 bar. The error automatically resolves, displaying the wording FH on the display.
  • Wording FH: Indicates the start of the air venting cycle. After restoring pressure, the boiler begins to eliminate the air present in the technical water, a process that lasts about 2 minutes.

Flat Primary Heat Exchanger for Boiler Euroterm MAIA PLUS D 24 S

Primary Heat Exchanger

The primary heat exchanger of the Euroterm MAIA PLUS D 24 S boiler is designed to maximize thermal efficiency. Made of copper, it offers a high heat exchange surface, ensuring optimal performance.

A key element is the overtemperature sensor, strategically positioned to monitor working conditions and prevent critical situations such as boiling at the hottest points of the exchanger.

Common issues with this component are related to pipe blockages, which can reduce water flow and cause noise. In these cases, it's often necessary to replace the exchanger.

A useful tip for prevention is the use of a Magnetic Filter, which helps prevent blockages in the exchanger, a critical component for the appliance's efficiency.

Problematic Fume Extractor Boiler Euroterm MAIA PLUS D 24 S

Fume Extractor

In the boiler Euroterm MAIA PLUS D 24 S, the fume extractor may experience problems such as centrifuge blockages or unusual noises due to friction or deformations. These signs should not be ignored, as they can lead to greater inefficiencies or dangers. Addressing these issues requires professional technical inspection, including cleaning and checking of critical components such as the air pressure switch and the centrifuge.

Paying special attention to these symptoms can prevent serious faults, keeping the boiler Euroterm MAIA PLUS D 24 S in optimal condition.

Grundfos UPS15/60 Circulation Pump Boiler Euroterm MAIA PLUS D 24 S

Grundfos UPS15/60 Pump Performance

Enhance the performance of your MAIA PLUS D 24 S boiler with the Grundfos UPS15/60 pump, designed for superior water circulation. Choose from three speed levels to maximize efficiency, with the third speed recommended for the best performance, except in the presence of circulation noises.

The pump, generally easy to install by a professional, may present difficulties in removing the stator from the cast iron head after a long period of use.

Technical specifications of the Grundfos UPS15/60:

  • Power Supply: 2.5 μF 230V - 50Hz IP44 TF 95
  • High Speed (III): 0.38 A - 85 W
  • Medium Speed (II): 0.30 A - 65 W
  • Low Speed (I): 0.21 A - 45 W

Suitable also as a replacement for models UPS 15-50, 15-60, 25-50, 25-60, 15-65, 25-65.

3/8 Automatic Plastic Air Purger for Euroterm MAIA PLUS D 24 S boiler

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 Euroterm MAIA PLUS D 24 S 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.

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 MAIA PLUS D 24 S 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.

Anti-Legionella Treatment in MAIA PLUS D 24 S Boiler

Anti-Legionella Treatment in MAIA PLUS D 24 S Boiler

The mandatory anti-Legionella treatment in the MAIA PLUS D 24 S boiler is crucial for ensuring the sanitary safety of water and preventing the formation of Legionella bacteria. This system, which automatically initiates a sterilization cycle according to the electronic board's programming, is essential for the health and safety of the user. Deactivating this mechanism is strongly discouraged as it could lead to significant health risks due to the potential proliferation of Legionella bacteria in the water storage.

Possible Improvement Works

The Euroterm MAIA PLUS D 24 S boiler requires special attention to the proper cleaning of the flue pipe. Especially at the bends leading to the vertical section, dirt can accumulate, compromising the functionality of the smoke fan. 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 MAIA PLUS D 24 S 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 Euroterm MAIA PLUS D 24 S 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 Euroterm MAIA PLUS D 24 S 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 MAIA PLUS D 24 S 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 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.

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Polyphosphate Dosing Pump

If the hardness of the tap water exceeds 20 French degrees, we suggest equipping the Euroterm MAIA PLUS D 24 S boiler with a polyphosphate doser.

Polyphosphates, available in powder or liquid form, are mixed with the cold water entering the Euroterm MAIA PLUS D 24 S 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.

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Customize Home Climate with a Thermostat

Get the most out of your Euroterm MAIA PLUS D 24 S boiler with a customizable room thermostat or programmable thermostat.

These solutions allow you to create the ideal home environment by regulating the temperature according to your specific needs. Choose a programmable thermostat to set varied schedules, adapting the home climate to your daily and weekly rhythms and improving energy efficiency.

Among the available models, you will find:

  • Daily Programmable Thermostats
  • Weekly Programmable Thermostats
  • Smart Thermostats with Smart Functions

The ideal choice should respond to your preferences and the technical characteristics of your Euroterm MAIA PLUS D 24 S boiler.

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.

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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.

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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.

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Frequent Questions

To help you resolve doubts and questions about your Euroterm MAIA PLUS D 24 S boiler model, we have prepared a list of Q&A covering the most common issues. Find the answers you are looking for optimal use 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.

What is the difference between COMFORT 1 and COMFORT 2?

The manufacturer offers two COMFORT functions for the MAIA PLUS D 24 S boiler, activated through the ECO/COMFORT1/COMFORT2 button.

  • Comfort 1: In this mode, you can adjust the domestic hot water temperature using the + and - buttons (near the faucet symbol).
  • Comfort 2: In this mode, the temperature is fixed at 45°C without the possibility of adjustment.

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 MAIA PLUS D 24 S 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 Euroterm.
  • 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.

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