Boiler Euroterm AURA R K 35 S PDF Manual – Complete Guide for Use and Maintenance
The Euroterm AURA R K 35 S condensing boiler is designed for the production of domestic hot water and heating through an external boiler. It uses condensing technology to recover heat from flue gases and achieve higher efficiency, requiring a drain due to high condensate production.
This boiler produces domestic hot water through an external storage tank, which needs a probe connected to the boiler’s terminal block. This makes it ideal for coupling with multi-coil boilers that can be interfaced with solar or hybrid systems. Therefore, if there is a storage tank coupled to the boiler and solar system, and the solar system is not active (e.g., in winter), the boiler starts producing domestic hot water.
Common Procedures
To maintain the safety, efficiency, reliability, and performance characteristics that distinguish the appliance, it is necessary to perform maintenance annually. Annual maintenance is essential for safety and continuous operation.
Optimal Temperature Settings for the Boiler
The Euroterm AURA R K 35 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.
Boiler Usage Warnings
To ensure the safety, efficiency, and performance of the AURA R K 35 S appliance, annual maintenance is crucial. It is highly discouraged to intervene inside the boiler without adequate technical skills. In case of anomalies or malfunctions, it is important to always consult a qualified technician. Annual maintenance by specialized personnel is essential for the safety and continuous functioning of the appliance.
Safety Regulations for Electric Energy
Safety in the use of the AURA R K 35 S 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.
What to Do in the Presence of Gas Odor
In situations of potential gas leakage, it is crucial to follow these guidelines:
- Avoid using any electrical device that could trigger sparks, including the phone.
- Immediately ventilate the environment by opening doors and windows.
- Close the gas taps to stop the leakage.
- Promptly call for urgent intervention by expert and qualified personnel.
The boiler should be used exclusively according to the manufacturer’s instructions and for heating water to safe temperatures. Improper use can cause serious damage. Ensure that installation and maintenance are entrusted to authorized technicians to avoid risks and ensure compliance with safety regulations.
Information on Components and Spare Parts
Here is an informative resource that covers a wide range of components and spare parts for the AURA R K 35 S boiler. Each element is described in detail to help you better understand its role within the appliance and how to maintain it optimally.
Boiler AURA R K 35 S Display
The display of the AURA R K 35 S boiler is information-rich and can be slightly confusing, but it displays essential parameters for operation. The Buttons:
- PLUS and MINUS Thermo: Use these buttons to increase and decrease the radiator temperature (not the ambient temperature).
- ECO/COMFORT: This button allows you to choose between ECO/COMFORT1/COMFORT2 modes for sanitary water.
- RESET: This button resets an error condition (everything but water shortage), and if held down, it enters the menu.
- SUN/SNOWFLAKE: Although the button appears large, it is a single button that switches between Summer and Winter.
Display readings:
- SUN/SNOWFLAKE: Indicates whether the boiler is in Winter or Summer mode.
- ECO/COMFORT: Indicates if the boiler is in ECO or Comfort mode.
- 1.2 bar: Shows the current pressure in the boiler.
- Drop Symbol: A drop-like symbol appears on the display, enlarging based on the flame’s power.
- Upper Temperature: It’s the Primary circuit temperature, which also rises in summer when the boiler produces DHW (Domestic Hot Water).
- Lower Temperature: It’s the current Sanitary water temperature.
Hot Water Production Mode in the Boiler
The production of domestic hot water (DHW) is enhanced with the introduction of the new COMFORT mode, selectable from the boiler’s control panel. The different modes include ECO, COMFORT1, and COMFORT2.
ECO Mode
In this boiler version, ECO mode turns off the domestic hot water.
COMFORT Mode
The COMFORT mode, in its two variants, involves preheating of DHW. COMFORT1 allows the user to adjust the temperature using the plus and minus buttons. COMFORT2, on the other hand, maintains a constant temperature of 45 degrees.
Temperature Adjustment
On the control panel of the Euroterm AURA R K 35 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 AURA R K 35 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).
Error Guide
- Error A01: If the flame locks, especially after changing the gas meter, press the Reset button for a reset. If it does not resolve, it is necessary to call support.
- Error F37: Check the pressure via the pressure gauge. If it is below 0.8 bar, there is a lack of water. To correct, increase the pressure at the filling tap to 1.5 bar. FH will appear on the display as confirmation of the reset.
- FH: This wording is shown when the boiler begins the expulsion of air from the technical water, a process that normally takes two minutes after adjusting the pressure.
Aluminum Heat Exchanger Component
In the Euroterm AURA R K 35 S boiler, the multi-layer aluminum exchanger represents the core of the system, integrating a ceramic burner and an efficient fin package. This component is responsible for generating and capturing heat for the heating system.
To ensure the maximum performance of the exchanger, meticulous maintenance is indispensable. Removing aluminum oxide residue between the fins is a key step in maintaining optimal performance. The recommended method includes the application of a specialized alkaline gel, followed by a thorough rinse.
Equally important is the maintenance of the condensation siphon. Neglecting it can lead to overheating of the exchanger, resulting in the expansion and rupture of the aluminum fins. In such circumstances, the most appropriate solution is replacing the exchanger to ensure the safety and efficiency of the entire system.
Grundfos UPS15/60 Boiler Circulator
The Grundfos UPS15/60 circulator is an optimal solution for water circulation in AURA R K 35 S boilers, ensuring efficiency and reliability. This model has three selectable speeds, with the highest speed recommended to maximize efficiency, unless there are noise disturbances from the circulating water.
Replacing this pump is usually a simple process for a qualified technician, although the stator can sometimes become stuck in the cast iron head after years of service, requiring special attention during removal.
Technical details of the UPS15/60 model:
- Capacity: 2.5 μF 230V – 50Hz IP44 TF 95
- Maximum Speed (III): 0.38 A – 85 W
- Medium Speed (II): 0.30 A – 65 W
- Low Speed (I): 0.21 A – 45 W
The UPS15/60 model is compatible for replacing various Grundfos motors, including UPS 15-50, 15-60, 25-50, 25-60, 15-65, 25-65.
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 AURA R K 35 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.
Motor Insert for Diverter Valve
The motor of the insert for the diverter valve, a crucial component in boilers, regulates the distribution of heat between the heating system and the sanitary water heating.
With a design that facilitates installation, the insert includes a motor with a connector, placed in the diverter valve for effective heat flow control.
It is important to monitor the insert to avoid issues such as motor breakdown, which can lead to uneven heat distribution, limiting heating to only one function.
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 AURA R K 35 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.
Boiler Errors and Anomalies AURA R K 35 S
The control board of the Euroterm AURA R K 35 S boiler is always capable of detecting anomalies. These anomalies can be blocking or non-blocking, and some may require a reset procedure. Below is a list of anomalies that may occur in the AURA R K 35 S boiler.
Boiler Errors and Anomalies for AURA R K 35 S
| Anomaly Code | Anomaly | Possible Cause | Solution |
|---|---|---|---|
| A01 | Burner Ignition Failure | Lack of gas | Check that the gas supply to the boiler is regular and that air has been eliminated from the pipes |
| Anomaly in ignition/detection electrode | Check the wiring of the electrode and that it is correctly positioned and free of encrustations | ||
| Faulty gas valve | Inspect and replace the gas valve | ||
| Insufficient network gas pressure | Check the network gas pressure | ||
| Blocked siphon | Inspect and possibly clean the siphon | ||
| A02 | Flame Signal Present with Burner Off | Anomaly in electrode | Check the wiring of the ionization electrode |
| Anomaly in board | Check the board | ||
| A03 | Over-Temperature Protection Intervention | Damaged heating sensor | Check the correct positioning and functioning of the heating sensor |
| Lack of water circulation in the system | Check the circulator | ||
| Air in the system | Vent the system | ||
| A04 | Flue Safety Intervention | Anomaly F07 generated 3 times in the last 24 hours | See anomaly F07 |
| A05 | Fan Protection Intervention | Anomaly F15 generated for 1 consecutive hour | See anomaly F15 |
| A06 | No Flame After Ignition Phase (6 times in 4 min.) | Anomaly in ionization electrode | Check the positioning of the ionization electrode and replace it if necessary |
| Unstable flame | Check the burner | ||
| Anomaly in gas valve offset | Check calibration of Offset at minimum power | ||
| Blocked air/flue duct | Clear any blockage from chimney, flue ducts and air intake and terminals | ||
| F07 | High Flue Gas Temperature | Partially blocked or insufficient chimney | Check the efficiency of the chimney, flue ducts and exit terminal |
| Flue gas sensor position | Check the correct positioning and functioning of the flue gas sensor | ||
| F10 | Anomaly in Supply Sensor 1 | Sensor damaged or wiring short-circuited | Check the wiring or replace the sensor |
| F11 | Anomaly in Return Sensor | Sensor damaged or wiring short-circuited | Check the wiring or replace the sensor |
| F12 | Sanitary Sensor Anomaly | Sensor damaged or wiring short-circuited | Check the wiring or replace the sensor |
| Interrupted wiring | Verify the presence of interruptions in the wiring and proceed with repair or replacement if necessary | ||
| F13 | Flue Gas Sensor Anomaly | Sensor damaged or wiring short-circuited | Check the wiring or replace the sensor |
| Interrupted wiring | Verify the presence of interruptions in the wiring and proceed with repair or replacement if necessary | ||
| F14 | Supply Sensor 2 Anomaly | Sensor damaged or wiring short-circuited | Check the wiring or replace the sensor |
| Interrupted wiring | Verify the presence of interruptions in the wiring and proceed with repair or replacement if necessary | ||
| F15 | Fan Anomaly | Lack of 230V power supply or interrupted tachometric signal | Check the wiring of the 3-pole and 5-pole connectors |
| Damaged fan | Check the fan | ||
| F34 | Supply Voltage Below 170V | Electrical network issues | Check the electrical system |
| F35 | Abnormal Network Frequency | Electrical network issues | Check the electrical system |
| F37 | Incorrect Water Pressure in the System | Pressure too low or water pressure switch not connected or damaged | Recharge the system or check the sensor |
| F39 | External Probe Anomaly | Damaged probe or short-circuited wiring | Check the wiring or replace the sensor |
| Probe disconnected after activating the sliding temperature | Reconnect the external probe or disable the sliding temperature | ||
| A41 | Sensor Positioning | Supply sensor detached from the pipe | Check the correct positioning and functioning of the heating sensor |
| F42 | Heating Sensor Anomaly | Damaged sensor | Replace the sensor |
Possible Improvement Works
The condensing boiler Euroterm AURA R K 35 S 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 AURA R K 35 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 AURA R K 35 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 AURA R K 35 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
You might consider a range of accessories that would enhance the functionality of the AURA R K 35 S boiler.
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.
Polyphosphate Dosing Pump
If the hardness of the tap water exceeds 20 French degrees, we suggest equipping the Euroterm AURA R K 35 S boiler with a polyphosphate doser.
Polyphosphates, available in powder or liquid form, are mixed with the cold water entering the Euroterm AURA R K 35 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.
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: 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 Euroterm AURA R K 35 S 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.
Aluminum Anode
The aluminum anode, used in boilers such as the Euroterm AURA R K 35 S, offers a longer lifespan compared to magnesium anodes. This flexible material allows for easy insertion and provides effective protection against corrosion.
The aluminum anode can last over 6 years, making it a cost-effective option for boiler maintenance.
Electronic Anode
The electronic anode is an advanced solution for corrosion protection in boilers like the Euroterm AURA R K 35 S. Thanks to its electronic control system, it monitors and adjusts the protective action according to the water conditions.
This type of anode requires less maintenance compared to traditional anodes and ensures more effective and long-lasting protection.
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 Euroterm AURA R K 35 S 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.
What is the difference between COMFORT 1 and COMFORT 2?
The manufacturer offers two COMFORT functions for the AURA R K 35 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.
Does the boiler support the Opentherm protocol?
YES: The boiler’s thermostat contacts are voltage-free (no tension) and can communicate with an Advanced Thermostat or Remote Control.
This allows you to:
- Set the domestic hot water temperature: Especially useful if the AURA R K 35 S boiler is difficult to reach (attic, basement, external technical room).
- Set the radiator temperature: In addition to room temperature, the advanced Opentherm chronothermostat can communicate with the boiler to adjust radiator temperatures.
- Set operating hours for domestic hot water: Useful for boilers with storage tanks, it can save on boiler maintenance costs (like gas).
- Error Management: With Opentherm 2 or with proprietary 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.
