ATTACK HRS 600 Buffer Tank with Built-in 160L DHW Tank and One Heat Exchanger (insulation included)

Product detailed description

ATTACK Buffer Tank HRS 600 with built-in 160L DHW tank and one heat exchanger (insulation included)

ATTACK buffer tanks with a 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 heating water charging. This choice determines how easily 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 a heating buffer. It has no DHW preparation built in, it serves solely to accumulate heating water and to hydraulically separate the heat source (e.g. a heat pump or a gasification boiler) from the heating circuit. DHW preparation in that case is solved with an external tank (e.g. the ATTACK Z range).
• HR – a tank with a built-in enamelled DHW tank with a volume of 160 l inside the buffer body (the "tank-in-tank" principle). It does not contain any additional heat exchanger – heating water is fed into the buffer tank directly, which makes it suitable especially 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 tank 160 l), complemented by one additional external heat exchanger for heating water charging. Thanks to this heat exchanger, HRS is also suitable for heat sources requiring hydraulic separation, for example a heat pump.
• TUV – a tank with a stainless steel coil inside, which ensures instantaneous (flow-through) heating of domestic hot water – cold water flows through the coil and is heated instantly, without the need for a separate DHW 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 heating water charging – the most versatile solution of the range, suitable also for heat sources requiring hydraulic separation (heat pump, combination of multiple sources).

ATTACK Buffer Tank HRS 600 with built-in 160L DHW tank and one heat exchanger (insulation included) belongs to the range of ATTACK buffer tanks with a heat exchanger in the 600-litre volume category. It is the HRS – buffer tank with built-in DHW tank and heat exchanger variant – a built-in enamelled DHW tank with a volume of 160 l inside the tank, complemented by one additional external heat exchanger for heating water charging. This page describes precisely this particular model, including its technical parameters, recommended heat sources and the most frequently asked customer questions.

Key features

• Removable soft insulation with a thickness of 100 mm in a durable leatherette (PVC) cover – easily removed and refitted during connection servicing, without permanently damaging the tank surface.
• Built-in enamelled domestic hot water tank with a volume of 160 l inside the buffer body (the "tank-in-tank" principle) – hot water prepared directly inside the tank body without the need for a separate external boiler.
• External heat exchanger for heating water charging with an estimated heat exchange surface of approx. 2.2 m², enabling 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 a water temperature of up to 95 °C.
• A prepared port with a G 6/4" thread for mounting an ATTACK TH electric heating element (2 – 6 kW) as a backup or supplementary heat source.
• Multiple ports (approx. 9 in total) for connecting the heat source(s), heating circuits, temperature sensors and venting – exact port layout according to the manufacturing documentation.
• Compact footprint with a height/diameter ratio optimised for passing 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 shell.
• Made in Slovakia, 24-month warranty from commissioning (max. 30 months from dispatch from the factory).

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 over the long term 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. The added external heat exchanger makes HRS a more versatile choice than HR – it is also suitable for heat sources requiring hydraulic separation, for example a heat pump, while retaining the convenience of the built-in 160 l DHW tank without the need for an external boiler.

The HRS600K tank is suitable for pairing 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 tank for DHW preparation (these boilers do not contain a tank themselves). We always recommend having the exact sizing of the pipework, pumps and safety fittings assessed by an authorised heating technician according to the project documentation of the specific building.

When installing, allow 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 heated building and the mode of operation. For wood gasification boilers (e.g. ATTACK DPX/SLX), a guideline of approx. 20 – 40 litres of buffer volume per 1 kW of boiler output is usually recommended, so that the boiler can burn out at full output even when there is no 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 usually a smaller volume than with wood boilers is sufficient. The HRS600K model with a volume of 600 litres is suitable as a guideline for a heat source with an output in the corresponding range – however, we always recommend having the exact calculation made by a heating technician based on the energy label or heat loss calculation of the specific building, not just on a table estimate.

Other volumes in the same HRS variant

If 600 litres is not exactly what you are looking for, we also offer the same design solution (a built-in enamelled DHW tank with a volume of 160 l inside the tank, complemented by one additional external heat exchanger for heating water charging) in our shop in other volume ranges:

• ATTACK Buffer Tank HRS 800 with built-in 160L DHW tank and one heat exchanger (insulation included) – 800 l
• ATTACK Buffer Tank HRS 1000 with built-in 160L DHW tank and one heat exchanger (insulation included) – 1000 l

A larger volume means a longer accumulation time and fewer charging/discharging cycles per day, which is gentler on the heat source, but at the same time 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 switch on more frequently.

Maintenance and operation

The HRS600K 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, 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 tank (HR/HRS), we recommend following the usual DHW 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 permanently damaging it.

Before first commissioning, we recommend having the system filled, vented and set up by an authorised technician, who will also confirm the commissioning date decisive for the warranty period.

Safety and standards

The HRS600K tank is intended for operation in closed heating systems and must always be complemented by a safety valve with the appropriate opening overpressure, 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 appropriate 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.

Transport and installation

We deliver the HRS600K tank within Slovakia by standard palletised transport; for larger volumes (from approx. 800 l upwards), we recommend checking in advance the clearance of doors and hallways along the route to the boiler room – the weight and dimensions in the parameters table are estimates, and we will gladly confirm the exact values for a specific unit before ordering. We recommend entrusting the actual connection to the heat source, electric heating element and controls to a professional installation company.

Who this solution is suitable for

We recommend the HRS600K tank with a volume of 600 litres especially for family houses and smaller premises that want to efficiently accumulate heating water while also solving DHW preparation in the manner typical of the chosen series (HRS – buffer tank with built-in DHW tank and heat exchanger). We recommend consulting the specific choice of volume and variant (AS/HR/HRS/TUV/TUVS) with a heating technician based on the building's heat loss, the number of people in the household, the chosen heat source(s) and the desired level of DHW comfort.

Frequently asked questions

What is the difference between the HRS600K tank and the other types in the AS/HR/HRS/TUV/TUVS range?
The HRS600K tank has a built-in enamelled DHW tank with a volume of 160 l inside the tank, complemented by one additional external heat exchanger for heating water charging. The other types in the range differ mainly in whether they have a built-in DHW tank (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 heating water charging they contain (0 or 1).

What volume of the HRS600K tank do I need for an average family household?
A tank with a volume of 600 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 according to the building's heat loss, the heat source output and the number of people in the household – we will gladly help you choose based on your specific input data.

What is the surface area of the heat exchanger for heating water charging?
The HRS600K tank has a heat exchanger with an estimated heat exchange surface of approximately 2.2 m², which is sufficient for efficiently charging the accumulated water volume in a reasonable time at typical heat source inlet temperatures. The exact heat exchanger output depends on the temperature difference and flow rate on the heat source side.

Is the built-in 160 l tank enough for hot water for the whole household?
The built-in enamelled tank with a volume of 160 l covers the normal operating consumption of a standard household (approx. 3 – 5 people) with adequate reheating. For higher peak consumption (e.g. several bathrooms at once), we recommend adding an external DHW tank or considering the TUV/TUVS variant with instantaneous heating, which is not limited by volume.

Is the HRS600K tank suitable for a heat pump?
Yes, the tank has an external heat exchanger for heating water charging, which provides the necessary hydraulic separation of the heat pump circuit from the house's heating circuit – a common connection for heat pumps by ATTACK as well as other manufacturers.

What is the maximum operating pressure and temperature load of the tank?
The buffer part 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 HRS600K tank insulated, and can the insulation be removed later for servicing?
The tank is equipped with soft removable insulation with a thickness of 100 mm in a leatherette cover, which is easily removed and refitted using hook-and-loop fasteners/straps without damage – useful when connecting ports, performing service work, 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, this is one of the main purposes 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 buffer 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 – the built-in enamelled DHW tank (HR/HRS), the stainless steel coil (TUV/TUVS) and/or the additional external heat exchanger (HRS/TUVS compared to HR/TUV). The more functions a tank integrates within itself, 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 HRS600K tank work?
After ordering, we dispatch the tank from the manufacturing 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 warranty period of 24 months from the commissioning date for the HRS600K buffer tank, but no more than 30 months from the date of dispatch from the factory. If you have any questions about choosing, connecting or servicing the tank, please do not hesitate to contact our sales department – we will be happy to help design the complete set including the heat source, circulation pumps and controls.