ATTACK TUV 800 Storage Tank with Stainless Steel Coil for DHW Heating (insulation included in price)

Product detailed description

ATTACK Buffer Tank TUV 800 with Stainless Steel Coil for DHW Heating (insulation included)

ATTACK buffer tanks with a heat exchanger form a complete range of five solutions, which differ from one another in the method of domestic hot water (DHW) preparation and the number of built-in heat exchangers for charging the heating water. It is precisely this choice that 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 – tank with one heat exchanger, purely 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 a gasification boiler) from the heating circuit. DHW preparation is in this case handled by an external cylinder (e.g. the ATTACK Z range).
• HR – tank with a built-in enamelled DHW cylinder with a volume of 160 l inside the accumulation body (a "tank-in-tank" principle). It does not contain any additional heat exchanger – heating water is fed directly into the buffer tank, which is why it is especially suitable for heat sources that do not require hydraulic separation (typically solid fuel boilers with their own circulation pump).
• HRS – the same construction as HR (built-in enamelled DHW cylinder, 160 l), supplemented with one additional external heat exchanger for charging the heating water. Thanks to this heat exchanger, the HRS is also suitable for heat sources requiring hydraulic separation, such as a heat pump.
• TUV – 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 cylinder. Heating water is fed in directly, without an additional heat exchanger.
• TUVS – a combination of TUV (stainless steel coil for instantaneous DHW heating) and one additional external heat exchanger for charging the heating water – the most versatile solution in the range, suitable also for heat sources requiring hydraulic separation (heat pump, combination of multiple sources).

ATTACK Buffer Tank TUV 800 with Stainless Steel Coil for DHW Heating (insulation included) belongs to the ATTACK range of buffer tanks with a heat exchanger in the 800-litre volume category. It is the TUV – buffer tank with a stainless steel coil for instantaneous DHW heating variant – a stainless steel coil inside the tank for instantaneous heating of domestic hot water, with no additional heat exchanger – heating water is fed in directly. This page describes precisely this specific model, including its technical parameters, recommended heat sources and the most frequently asked customer questions.

Key Features

• Removable soft insulation, 100 mm thick, in a durable leatherette (PVC) cover – easily removed and refitted during connection servicing, without the need to permanently damage the tank's surface.
• Internal stainless steel coil for instantaneous (hygienic) heating of domestic hot water with an estimated heat exchange area of approx. 3.2 m² – no stagnant water, minimal risk of bacteria proliferation including legionella.
• External heat exchanger for charging the heating water with an estimated heat exchange area of approx. 3.2 m², enabling hydraulic separation of the heat source (e.g. a heat pump) from the heating circuit.
• Welded steel body with an internal anti-corrosion treatment, designed for a max. operating pressure of 3 bar and a water temperature of up to 95 °C.
• Prepared connection with a G 6/4" thread for installing an ATTACK TH electric heating element (2 – 6 kW) as a backup or supplementary heat source.
• Multiple connections (approx. 7 in total) for connecting the heat source(s), heating circuits, temperature sensors and venting – exact layout of connections according to the manufacturing documentation.
• Compact footprint with a height/diameter ratio optimised to pass through standard doors and staircases when installing in a boiler room or utility room.
• Option to combine several heat sources simultaneously (heat pump, wood gasification boiler, solar system, electric heating element) thanks to multiple connection levels on the tank's shell.
• Made in Slovakia, 24-month warranty from commissioning (max. 30 months from dispatch from production).

Technical Parameters

Installation Recommendations

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

The TUV800K 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 require an external indirectly heated cylinder for DHW preparation (these boilers do not include a cylinder themselves). We always recommend having the exact sizing of the piping, pumps and safety fittings assessed by a qualified heating engineer according to the specific building's project documentation.

When installing, allow for sufficient space around the tank for service access to the connections, sensors and a possible 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 heated building 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 out at full output even outside immediate heat demand in the house. For heat pumps, the volume is more a matter of hydraulic balancing of the circuit and the number of heating zones, and a smaller volume than for wood boilers is usually sufficient. The TUV800K model with an 800-litre volume is roughly suitable for a heat source with output in the corresponding range – however, we always recommend having the exact calculation done by a heating engineer based on the energy label or a heat calculation of the specific building, not just according to a table estimate.

Other Volumes in the Same TUV Variant

If an 800-litre volume 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, with no additional heat exchanger – heating water is fed directly) in our e-shop in other volume ranges:

• ATTACK Buffer Tank TUV 500 with Stainless Steel Coil for DHW Heating (insulation included) – 500 l
• ATTACK Buffer Tank TUV 600 with Stainless Steel Coil for DHW Heating (insulation included) – 600 l
• ATTACK Buffer Tank TUV 1000 with Stainless Steel Coil for DHW Heating (insulation included) – 1000 l

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

Maintenance and Operation

The TUV800K buffer tank requires minimal maintenance – we recommend checking the tightness of all connections once a year, the function of the safety valve and the condition of the insulation. For tanks with a stainless steel coil (TUV/TUVS), it is advisable to occasionally check the flow rate and, in hard water areas, to 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 cylinder (HR/HRS), we recommend following standard DHW cylinder maintenance practices, including occasional checks of the anode, if included in the design. The removable insulation allows quick and safe access for all these servicing tasks without the need to permanently damage it.

Before first 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 TUV800K 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 of 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 relevant authorisation in accordance with applicable legislation and technical standards for pressure vessels and heating systems. Failure to comply with these principles may lead to limitation or loss of the warranty.

Delivery and Installation

We deliver the TUV800K tank within Slovakia by standard palletised transport; for larger volumes (from approx. 800 l upwards), we recommend checking in advance the passability of doors and corridors along the route to the boiler room – the weight and dimensions in the parameters table are approximate estimates, we will gladly confirm the exact values for a specific unit before ordering. We recommend entrusting the actual connection to the heat source, the electric heating element and the controls to a professional installation company.

Who This Solution Is Suitable For

We recommend the TUV800K tank with an 800-litre volume primarily for family houses and smaller facilities 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 a 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 engineer according to the building's heat loss, the number of people in the household, the chosen heat source(s) and the desired comfort level of hot water preparation.

Frequently Asked Questions

What is the difference between the TUV800K tank and the other types in the AS/HR/HRS/TUV/TUVS range?
The TUV800K tank has a stainless steel coil inside the tank for instantaneous heating of domestic hot water, with no additional heat exchanger – heating water is fed directly. Other types in the range differ mainly in whether they have a built-in DHW cylinder (HR, HRS), a stainless steel coil for instantaneous heating (TUV, TUVS), or no DHW preparation at all (AS), and in how many external heat exchangers for charging the heating water they contain (0 or 1).

What volume of the TUV800K tank do I need for a typical family household?
A tank with an 800-litre volume 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 according to the building's heat loss, the heat source output and the number of people in the household – we are happy to help you choose based on specific input data.

What is the area of the heat exchanger for charging the heating water?
The TUV800K tank has a heat exchanger with an estimated heat exchange area of approximately 3.2 m², which, at typical heat source inlet temperatures, is sufficient for efficiently charging the accumulated volume of water within a reasonable time. The exact performance of the heat exchanger depends on the temperature difference and flow rate on the heat source side.

Why is a stainless steel coil better than a classic DHW cylinder?
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 bacteria proliferation, including legionella. At the same time, there is no need to keep a hot water cylinder on standby, which saves energy outside of peak demand.

Is the TUV800K tank suitable for a heat pump?
Yes, the tank has an external heat exchanger for charging the heating water, which provides the necessary hydraulic separation of the heat pump circuit from the house's heating circuit – a standard 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 accumulation 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; the 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 TUV800K 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 refitted using Velcro/straps without damage – useful when connecting fittings, servicing, or additionally installing sensors and heating elements.

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

Is it possible to additionally install an electric heating element?
Yes, the tank has a prepared connection 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 cylinder (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 TUV800K 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 interested, we can also recommend compatible accessories (ATTACK TH electric heating elements, circulation pumps, controls) so that you receive a complete functional set in a single order.

Warranty

We provide a 24-month warranty period for the TUV800K buffer tank from the date of commissioning, 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 are happy to help design the whole system, including the heat source, circulation pumps and controls.