ATTACK Stationary Stainless Steel Storage DHW Heater HP 200 INOX

Product detailed description

The ATTACK Stationary Stainless Steel DHW Tank HP 200 INOX is a stationary domestic hot water (DHW) storage tank made of stainless steel with a capacity of 200 litres, optimized for cooperation with a heat pump (heat exchanger with a larger heat transfer area suitable for the lower heating water temperatures typical of heat pumps). The stainless steel (INOX) design guarantees permanent corrosion resistance without the need for a magnesium anode and its regular replacement, which represents a significant saving in maintenance and operating costs over time compared to classic enamelled tanks.

Key features

• Capacity of 200 litres of domestic hot water, stainless steel (INOX) design without the need for anode protection
• Internal heat exchange surface with an area of approx. 2.0 m² for efficient heat transfer from the source to the DHW
• Hygienically safe, smooth inner surface limiting limescale build-up
• HP series - especially suitable in combination with the ATTACK Inverter R32 heat pump
• Thermal insulation jacket limiting heat losses of the prepared DHW
• Set of G 6/4" threaded fittings for connecting the heat source, circulation, sensors, and an electric heating element
• Possibility of adding an electric heating element for additional heating or as a backup source
• Low maintenance requirements - no need to check/replace the anode typical of enamelled tanks

How DHW preparation works in this tank

The heat source (heat pump, solar collectors or boiler) heats the heat transfer medium, which circulates through the built-in heat exchanger inside the stainless steel vessel. Heat is transferred to the cold utility water filled in the tank, which stratifies due to temperature differences - the warmest water accumulates at the top near the outlet fitting, while the coldest water flows in from below from the cold water inlet. This allows hot water to be drawn practically continuously, even during reheating.

In the HP variant, the heat exchanger is designed to match the nature of the given source - for a heat pump, this means lower heating water temperatures, and therefore a larger heat exchange area, which compensates for the smaller temperature gradient.

Overview of the ATTACK stationary stainless steel DHW tank series

For better orientation in the product range, here is an overview of the entire series of stainless steel stationary DHW tanks, of which this specific model, the ATTACK Stationary Stainless Steel DHW Tank HP 200 INOX, is a part.

Installation and use

The ATTACK Stationary Stainless Steel DHW Tank HP 200 INOX is installed in a vertical position on a flat and sufficiently load-bearing surface (empty weight approx. 55.0 kg, significantly more when filled, so the load-bearing capacity of the floor at the installation site must be taken into account). Connection of the primary circuit (heat source) and the secondary DHW circuit is made via a set of G 6/4" threaded fittings. On the hot water outlet, we recommend installing a thermostatic mixing valve to protect against scalding, and on the cold water inlet, a check valve and a safety valve in accordance with applicable standards for pressure vessels.

Water quality and system filling

On the domestic hot water side, for harder water (above approx. 15-20 °dH), we recommend considering upstream water treatment (a softener or dosing device), which will limit limescale formation on the heat exchanger and extend intervals between service descaling. On the primary (heating) side, the same principles apply as for other hot water systems - suitable treatment of the fill water, thorough air removal, and, if necessary, a corrosion inhibitor compatible with the aluminium heat exchangers of the heat pump.

Energy efficiency of DHW preparation

Preparing domestic hot water via the large-area heat exchanger in the ATTACK Stationary Stainless Steel DHW Tank HP 200 INOX allows for more efficient use of either the lower outlet temperatures of a heat pump (HP series) or the variable heat gain of solar collectors (SOL series) than would be the case with direct instantaneous heating. A larger accumulated volume also reduces the number of heat source starts and allows better use of cheaper electricity (e.g. during off-peak tariffs) to preheat the tank outside peak hours.

Practical application examples

Family house with a heat pump: The ATTACK Stationary Stainless Steel DHW Tank HP 200 INOX is connected to the primary circuit of an ATTACK Inverter R32 heat pump, which usually prepares domestic hot water outside heating peak periods (e.g. in the early morning or afternoon hours) so as not to limit the output intended for space heating. Thanks to the large-area heat exchanger, the tank can efficiently use even the lower outlet temperatures typical of heat pump operation.

Combination with solar collectors (SOL series): For SOL series models, the tank is connected to the solar collector circuit, which covers most of the DHW heating needs practically free of charge during sunny months. During cloudy days or in winter, an electric heating element or connection to a boiler/heat pump is used as a supplementary (bivalent) source.

Compatibility with ATTACK heat pumps and boilers

The ATTACK Stationary Stainless Steel DHW Tank HP 200 INOX is a suitable addition to heat pumps from the ATTACK Inverter R32 Air/Water series as well as to stationary boilers from the ATTACK product range (e.g. wood gasification boilers or cast iron combined boilers) that require an external tank for DHW preparation. When combining several sources (e.g. solar collectors + heat pump), it is advisable to design the hydraulic connection with a controller that prioritizes the cheaper/renewable heat source over more expensive reheating.

Stainless steel (INOX) tank vs. classic enamelled tank

The higher purchase price of the ATTACK Stationary Stainless Steel DHW Tank HP 200 INOX stainless steel tank is generally offset over time by lower maintenance costs and a longer expected service life compared to the enamelled version, especially in areas with more aggressive water.

Safety features and related standards

The installation of the DHW tank must include a safety valve on the hot water side with the appropriate opening pressure, an expansion vessel for DHW, and a check valve on the cold water inlet. We also recommend a thermostatic mixing valve on the hot water outlet for both hygienic and safety reasons (protection against scalding). Installation should comply with the requirements of the relevant technical standards and should be carried out by a professionally qualified person.

Tank maintenance

The recommended scope of annual maintenance includes checking the function of the safety valve, checking the tightness of flanges and connections, possible descaling of the heat exchanger in harder water, and checking the setting of the mixing valve. Since the vessel is made of stainless steel, there is no need to care for a magnesium anode as is typical for enamelled tanks.

Environmental and sustainability aspect

More efficient DHW preparation using a heat pump or solar collectors instead of direct electric heating means lower primary energy consumption and lower emissions associated with hot water production. The stainless steel design of the tank without a magnesium anode also reduces the amount of consumable material replaced over the entire service life of the device.

Delivery and handling

The product is delivered by pallet transport, usually within a few business days of ordering (we will confirm the exact delivery date after receiving your order, as some models are manufactured or completed to order). Given the weight of the product (approx. 55.0 kg), we recommend ensuring suitable handling equipment (pallet truck, or a second person) when receiving the shipment, and checking that the packaging is undamaged upon receipt in order to preserve any potential claim for transport damage.

About the manufacturer ATTACK

ATTACK, s.r.o. is a Slovak manufacturer of heating technology with a long tradition in the development and production of boilers, heat pumps and related accessories, including storage and buffer tanks. Production directly in Slovakia ensures good availability of spare parts and service support for both end customers and installation companies.

Technical parameters

Note: dimensions, weight and heat exchanger area are approximate estimates for the given type series based on tank volume; please verify exact values in the manufacturer's current data sheet or request them when ordering.

Frequently asked questions

Why choose a stainless steel (INOX) DHW tank instead of an enamelled one?

Stainless steel is corrosion-resistant by nature of the material, so the tank does not need a magnesium anode or its replacement. The inner surface is smooth and hygienically safe, which reduces the risk of limescale build-up and is also suitable for areas with more aggressive water.

How often does this tank need servicing?

We recommend checking the function of the safety valve once a year, possibly descaling the heat exchanger (if the water is harder), and checking the tightness of the flanges. Since there is no need to care for an anode, the servicing requirements are lower compared to enamelled tanks.

Can the tank be combined with both solar collectors and a heat pump at the same time?

Yes, for models with a heat exchanger (SOL, HP), reheating can also be solved in combination - for example, a solar circuit as the primary source and a heat pump/boiler as reheating via a second fitting or an electric heating element, depending on the specific hydraulic scheme of the project.

What is the difference between the HP and SOL series?

The HP series is optimized for operation with a heat pump (heat exchanger with a larger heat transfer area for the lower heating water temperatures typical of heat pumps), while the SOL series is designed primarily for solar collector systems (heat exchanger sized for the nature of the solar circuit). Both can in practice be combined with another heat source; the specific recommendation depends on the project.

What does the HYDRO COMBI designation mean and how does it differ from a regular DHW tank?

HYDRO COMBI combines a buffer tank for heating water and a separate space/heat exchanger for domestic hot water preparation in one stainless steel unit. This simplifies installation and reduces the number of components and space requirements in the boiler room compared to two separate tanks.

Is it necessary to use a mixing valve on the DHW outlet?

For models with higher achievable temperatures (e.g. when reheating with an electric element or a solar circuit), we strongly recommend a thermostatic mixing valve on the hot water outlet, which protects against scalding and extends the service life of the DHW piping.

What is the maximum operating temperature and pressure?

ATTACK stainless steel tanks are typically designed for an operating pressure of up to 6 bar on the DHW side and up to 3 bar on the heating water side, with a maximum temperature of up to approx. 95 °C on the primary circuit - exact values can be found on the type plate of the specific model.

Is an expansion vessel also needed on the DHW side?

Yes, in a closed cold water distribution system (e.g. with a shut-off valve upstream of the water meter or a check valve), an expansion vessel for DHW must be installed on the cold water inlet to the tank, which absorbs the volumetric expansion of the heated water and protects against unnecessary opening of the safety valve.

How long does it take to heat the entire tank volume to the desired temperature?

The heating time depends on the output of the connected heat source (heat pump, boiler, solar collectors) and the temperature gradient, usually ranging from 1 to 3 hours for typical outputs of sources used in family houses. We can provide a precise estimate if we know the specific combination of heat source and tank volume.

Can the tank later be extended with a second heat exchanger, for example for solar collectors?

The tank's construction is fixed from manufacturing; it is not possible to additionally install another heat exchanger into an existing tank. If you plan to add solar collectors in the future, we recommend taking this requirement into account when choosing the model (SOL series or a model with two heat exchangers) before purchase.

What to do if there is an odour at the outlet or the water is cloudy?

If the tank is not used for a long time or if the cold water supply is interrupted, water stagnation and bacterial growth can occur. We recommend flushing the tank with a larger volume of water after a longer period of inactivity, and if problems persist, contacting a service technician who will check the temperature setting (regular heating above 60 °C is recommended as prevention against Legionella growth).

Warranty and service

This ATTACK brand product is covered by a standard warranty period of 24 months from commissioning, but no more than 30 months from the date of dispatch from the factory. For selected products and upon registration of commissioning by an authorized service technician, an extended warranty can also be arranged - please check the specific conditions when ordering or with our sales department. Service and spare parts are provided by the ATTACK authorized service partner network in Slovakia; spare parts are usually in stock.

Before commissioning, we recommend having the connection and filling of the system checked by a professionally qualified person (heating technician/service technician) in order to meet the conditions for full warranty coverage.

Summary

ATTACK Stationary Stainless Steel DHW Tank HP 200 INOX - a stationary stainless steel DHW tank with a capacity of 200 l, HP series, without a magnesium anode, suitable for use with an ATTACK Inverter R32 heat pump.