ATTACK TUV 500 Storage Tank with Stainless Steel Coil for DHW Heating (insulation included in price)

Product detailed description

ATTACK Buffer Tank TUV 500 with Stainless Steel Coil for DHW Heating (insulation included in price)

ATTACK buffer tanks with heat exchanger form a complete range of five solutions, which differ from each other in the way domestic hot water (DHW) is prepared and in the number of built-in heat exchangers for charging heating water. This choice is exactly what determines how simply and at what cost you can connect the tank to a heat pump, a wood gasification boiler, a gas boiler, or solar collectors:

• AS – a tank with one heat exchanger, purely for heating accumulation. It has no built-in DHW preparation inside, it serves exclusively for accumulating heating water and hydraulically separating the heat source (e.g. a heat pump or gasification boiler) from the heating circuit. DHW preparation in this case is solved by an external storage tank (e.g. the ATTACK Z range).
• HR – a tank with a built-in enamelled DHW storage tank with a volume of 160 l inside the buffer tank body (a "tank in a tank" principle). It contains no additional heat exchanger – heating water is fed directly into the buffer tank, therefore it is best suited to heat sources that do not require hydraulic separation (typically solid fuel boilers with their own circulation pump).
• HRS – the same design as HR (built-in enamelled DHW tank 160 l), supplemented with one additional external heat exchanger for charging heating water. Thanks to this heat exchanger, HRS is also suitable for heat sources that require hydraulic separation, for example a heat pump.
• TUV – a tank with a stainless steel coil inside, which ensures instantaneous heating of domestic hot water – cold water flows through the coil and is heated immediately, without the need for a separate DHW storage tank. Heating water is fed in directly, without any additional heat exchanger.
• TUVS – a combination of TUV (stainless steel coil for instantaneous DHW heating) and one additional external heat exchanger for charging heating water – the most versatile solution in the range, also suitable for heat sources requiring hydraulic separation (heat pump, combination of multiple sources).

ATTACK Buffer Tank TUV 500 with Stainless Steel Coil for DHW Heating (insulation included in price) belongs to the ATTACK range of buffer tanks with heat exchanger in the 500-litre volume category. It is the TUV – buffer tank with stainless steel coil for instantaneous DHW heating variant – a stainless steel coil inside the tank for instantaneous heating of domestic hot water, without any additional heat exchanger – heating water is fed in directly. This page describes exactly this specific model including its technical parameters, recommended heat sources, and frequently asked customer questions.

Key features

• Removable soft insulation 100 mm thick in a durable leatherette (PVC) cover – easily removed and reattached during connection servicing, without the need to permanently damage the tank surface.
• Internal stainless steel coil for instantaneous (hygienic) heating of domestic hot water with an estimated heat exchange area of approx. 2.5 m² – no stagnant water, minimal risk of bacteria growth including legionella.
• External heat exchanger for charging heating water with an estimated heat exchange area of approx. 2.5 m², allowing hydraulic separation of the heat source (e.g. a heat pump) from the heating circuit.
• Welded steel body with an anti-corrosion internal coating, designed for a max. operating pressure of 3 bar and water temperature up to 95 °C.
• Prepared port with G 6/4" thread for installation of an ATTACK TH electric heating element (2 – 6 kW) as a backup or supplementary heat source.
• Several ports (approx. 7 in total) for connecting heat source(s), heating circuits, temperature sensors, and venting – exact port layout according to the manufacturer's documentation.
• Compact footprint with a height/diameter ratio optimised for passing through standard doors and staircases when installing into a boiler room or utility room.
• Possibility of combining multiple heat sources simultaneously (heat pump, wood gasification boiler, solar system, electric heating element) thanks to multiple connection levels on the tank shell.
• Manufactured in Slovakia, 24-month warranty from commissioning (max. 30 months from dispatch from production).

Technical parameters

Installation recommendations

Thanks to the removable soft insulation 100 mm thick with a practical leatherette cover, the tank retains water temperature over the long term even outside the heating season, and access to the insulation during connection servicing is easy – the insulation can be removed and reattached at any time without damage. Instantaneous heating via the stainless steel coil means practically unlimited amounts of hot water without the risk of bacterial growth (legionella) typical of stagnant water in a classic storage tank, since the water in the coil does not stagnate. Without a heat exchanger on the heating water side, the TUV variant is suitable for sources with their own circulation pump, e.g. ATTACK DPX/SLX gasification boilers connected directly.

The TUV500K tank is suitable for a system with ATTACK heat sources – with ATTACK DPX/SLX wood gasification boilers (which require heating water accumulation due to the combustion process), with heat pumps, as well as with ATTACK EKO/PLQ/KLQ/E/EZ COMBI stationary cast-iron gas boilers, which need an external indirect DHW storage tank for hot water preparation (these boilers themselves do not include a storage tank). We always recommend having the exact sizing of pipework, pumps, and safety fittings assessed by a qualified heating technician according to the project documentation of the specific building.

When installing, allow for sufficient space around the tank for service access to the ports, sensors, and any electric heating element. We recommend installing a safety valve, an expansion vessel, and a venting valve at the highest point of the system in accordance with applicable standards for closed heating systems.

How to correctly size the buffer tank volume

The buffer tank volume should be based primarily on the heat source output, the heat loss of the building being heated, and the mode of operation. For wood gasification boilers (e.g. ATTACK DPX/SLX), a guideline of approximately 20 – 40 litres of accumulation per 1 kW of boiler output is usually recommended, so the boiler can burn down at full output even outside the immediate heat demand of the house. For heat pumps, the volume is more a matter of hydraulic circuit balancing and the number of heating zones, and usually a smaller volume suffices than for wood boilers. The TUV500K model with a volume of 500 litres is roughly suitable for a heat source with an output in the corresponding range – however, we always recommend having the exact calculation done by a heating technician based on the energy label, i.e. a heat calculation of the specific building, not just a table estimate.

Other volumes in the same TUV variant

If a volume of 500 litres is not exactly what you are looking for, we also offer the same design solution (a stainless steel coil inside the tank for instantaneous heating of domestic hot water, without any additional heat exchanger – heating water fed in directly) in our shop in other volume ranges:

• ATTACK Buffer Tank TUV 600 with Stainless Steel Coil for DHW Heating (insulation included in price) – 600 l
• ATTACK Buffer Tank TUV 800 with Stainless Steel Coil for DHW Heating (insulation included in price) – 800 l
• ATTACK Buffer Tank TUV 1000 with Stainless Steel Coil for DHW Heating (insulation included in price) – 1000 l

A larger volume means a longer accumulation time and fewer charge/discharge cycles per day, which saves the heat source, but also requires more space in the boiler room and a higher purchase price. A smaller volume is cheaper and more compact, but if undersized, the heat source may cycle more frequently.

Maintenance and operation

The TUV500K buffer tank requires minimal maintenance – we recommend checking the tightness of all ports and connections, the function of the safety valve, and the condition of the insulation once a year. For tanks with a stainless steel coil (TUV/TUVS), it is advisable to occasionally check the flow rate, and in harder water areas, consider filtration at the cold water inlet, which extends the coil's service life and maintains stable flow performance. For variants with a built-in storage tank (HR/HRS), we recommend following the usual DHW storage tank maintenance principles, including occasional inspection of the anode, if included in the design. The removable insulation allows quick and safe access for all these service tasks without the need for permanent damage.

Before initial commissioning, we recommend having the system filled, vented, and set up by a qualified technician, who will also confirm the commissioning date, which is decisive for the warranty period.

Safety and standards

The TUV500K tank is intended for operation in closed heating systems and must always be supplemented with a safety valve with the appropriate opening pressure, an expansion vessel with sufficient volume, and a venting valve at the highest point of the circuit. Installation, connection, and initial commissioning may only be carried out by a person with the appropriate authorisation in accordance with applicable legislation and technical standards for pressure vessels and heating systems. Failure to comply with these principles may result in the limitation or voiding of the warranty.

Delivery and installation

We deliver the TUV500K tank to Slovakia by standard pallet transport; for larger volumes (from approx. 800 l upwards), we recommend checking in advance the passability of doors and corridors on the route to the boiler room – the weight and dimensions in the parameters table are approximate estimates, we will gladly confirm exact values for a specific unit before ordering. We recommend entrusting the actual connection to the heat source, electric heating element, and control system to a professional installation company.

Who is this solution suitable for

The TUV500K tank with a volume of 500 litres is recommended especially for family houses and smaller operations that want to efficiently accumulate heating water while also solving domestic hot water preparation in the manner typical of the chosen series (TUV – buffer tank with stainless steel coil for instantaneous DHW heating). We recommend consulting the specific choice of volume and variant (AS/HR/HRS/TUV/TUVS) with a heating technician according to the building's heat loss, the number of people in the household, the chosen heat source(s), and the required comfort of hot water preparation.

Frequently asked questions

What is the difference between the TUV500K tank and other types in the AS/HR/HRS/TUV/TUVS range?
The TUV500K tank has a stainless steel coil inside the tank for instantaneous heating of domestic hot water, without any additional heat exchanger – heating water is fed in directly. The other types in the range differ mainly in whether they have a built-in DHW storage tank (HR, HRS), a stainless steel coil for instantaneous heating (TUV, TUVS), or no hot water preparation at all (AS), and in how many external heat exchangers for charging heating water they contain (0 or 1).

What volume of TUV500K tank do I need for a typical family household?
A tank with a volume of 500 litres is intended for households and buildings where accumulation corresponding roughly to this output and consumption range is needed. We always recommend calculating the exact volume based on the building's heat loss, heat source output, and number of people in the household – we will gladly help you choose based on your specific input data.

What is the area of the heat exchanger for charging heating water?
The TUV500K tank has a heat exchanger with an estimated heat exchange area of approximately 2.5 m², which, under normal heat source inlet temperatures, is sufficient for efficient charging of the accumulated water volume within a reasonable time. The exact heat exchanger performance depends on the temperature difference and flow rate on the heat source side.

Why is a stainless steel coil better than a classic DHW storage tank?
Water intended for drinking and cooking continuously flows through the coil and does not remain stagnant for long periods in a separate volume, which significantly reduces the risk of bacterial growth including legionella. At the same time, there is no need to keep a hot water storage tank on standby, which saves energy outside of peak demand.

Is the TUV500K tank suitable for a heat pump?
Yes, the tank has an external heat exchanger for charging heating water, which provides the necessary hydraulic separation of the heat pump circuit from the house's heating circuit – a common connection for ATTACK heat pumps as well as those of other manufacturers.

What is the maximum operating pressure and temperature load of the tank?
The buffer section of the tank is designed for a max. operating pressure of 3 bar and a max. water temperature of 95 °C. The heat exchanger/coil circuit withstands comparable values; exact maximum parameters can be found in the technical table below and always also in the accompanying documentation supplied with the tank.

How is the TUV500K tank insulated, and can the insulation be removed later for servicing?
The tank is equipped with soft removable insulation 100 mm thick in a leatherette cover, which is easily removed and reattached using hook-and-loop fasteners/straps without damage – useful when connecting ports, servicing, or additionally installing sensors and heating elements.

Can the tank be combined with multiple heat sources at once (e.g. heat pump and solar)?
Yes, that is one of the main purposes of a buffer tank with heat exchanger – it allows combining multiple heat sources (heat pump, wood gasification boiler, solar system, electric heating element) into a single buffer tank body. We recommend having the exact connection and the number of required ports designed by a heating technician according to the specific combination of sources.

Is it possible to additionally fit an electric heating element?
Yes, the tank has a prepared port with a G 6/4" thread for ATTACK TH electric heating elements (e.g. TH100, TH102, TH103, TH107 with an output of 2 – 6 kW), which serve as a backup or supplementary heat source.

Is the price difference between AS, HR, HRS, TUV, and TUVS just about additional equipment?
Yes, the price difference between the individual variants of the same volume reflects the amount of built-in components – a built-in enamelled DHW storage tank (HR/HRS), a stainless steel coil (TUV/TUVS), and/or an additional external heat exchanger (HRS/TUVS compared to HR/TUV). The more functions a tank integrates, the higher the purchase price, but at the same time you do not need to buy and install separate additional devices.

How does ordering and delivery of the TUV500K tank work?
After ordering, we dispatch the tank from the production warehouse in Slovakia, and we will inform you of the delivery date by e-mail or phone. If you are interested, we can also recommend compatible accessories (ATTACK TH electric heating elements, circulation pumps, controls) so that you receive a complete functional set with a single order.

Warranty

We provide a warranty period of 24 months from the date of commissioning for the TUV500K buffer tank, but no more than 30 months from the date of dispatch from production. If you have any questions about choosing, connecting, or servicing the tank, please do not hesitate to contact our sales department – we will gladly help design the entire system, including the heat source, circulation pumps, and controls.