ATTACK Wall-mounted Horizontal Tank Z 160 OKCV - right

Product detailed description

ATTACK Wall-mounted horizontal storage tank Z 160 OKCV - right is an indirectly heated wall-mounted domestic hot water (DHW) storage tank with a volume of 160 litres in a horizontal OKCV design with a right-hand connection orientation. The tank is designed to be hung above a suspended ceiling, in the space above a boiler, in a kitchen unit, or in another low-clearance space where a standard upright tank would not fit. Like the other models in the Z range, it is an indirectly heated type - it has no heat source of its own; the water is heated by heating water from the connected ATTACK gas boiler via an internal heat exchanger.

The "right-hand" connection orientation indicates on which side of the tank (viewed from the front) the water and heat exchanger inlets and outlets are located - this orientation must be chosen according to the layout of the pipework and the installation space, which is why the OKCV 160 model is manufactured in both versions (right-hand and left-hand).

Key features

• Inner tank made of steel sheet with a high-quality enamelled (glazed) surface resistant to corrosion and limescale build-up
• Magnesium protective anode against electrochemical corrosion of the tank - extends the service life of the tank and is easily replaceable during a service inspection
• Hardened PUR foam thermal insulation wrapped in an outer casing, which minimises heat loss during hot water storage
• Internal steel heating coil (heat exchanger) with a heat exchange area of 1.2 m² for indirect water heating from the boiler
• Suitable for connection to stationary ATTACK gas boilers (EKO COMBI, PLQ COMBI, KLQ COMBI, E COMBI, EZ COMBI ranges) as well as to other heat sources with a correctly sized heat exchanger
• Opening/pocket for a thermometer or thermostatic sensor for heating control
• Outlet for an optional electric heating element (purchased separately) for additional heating outside the heating season, when the boiler is not running
• Drain valve for easy draining and maintenance of the tank
• Robust construction with enamelling tested according to European standards for drinking water tanks
• Manufactured under the ATTACK brand - a proven Slovak manufacturer of heating technology

Type and version - right-hand orientation

The horizontal OKCV design is installed suspended below the ceiling or in a suspended ceiling using hanging straps or a bracket (it is not designed to stand on the floor). This position is advantageous in spaces with low ceiling height, for example above a wall-hung boiler, in a technical shaft, or in a kitchen unit.

The tank is manufactured in two mirror-image versions - right-hand (P) and left-hand (L) - depending on which side the cold/hot water and heat exchanger connections are located when viewed from the front of the tank. This particular product is in the right-hand version; if the project or existing piping requires the opposite side, a mirrored left-hand version is also available (same 160 l volume, only the connection positions differ).

Before ordering, we recommend verifying the right-hand/left-hand version directly at the installation site according to the pipe routing, to avoid unnecessary replacement.

Technical specification

Note: dimensions and weight are approximate estimates based on the volume and design type of the tank; exact values can be found in the manufacturer's technical data sheet or requested when ordering.

How indirect hot water heating works

The ATTACK Wall-mounted horizontal storage tank Z 160 OKCV - right is not a heat source itself - it has no burner or electric heating cartridge of its own (that is only an optional accessory). The heating principle is as follows: heating water heated in the ATTACK gas boiler flows via a circulation pump into the internal steel heat exchanger (coil) immersed in the tank. Through the wall of the heat exchanger, it transfers heat to the domestic water filling the tank's internal volume of 160 litres. The domestic water and the heating water never physically meet - they are separated by the heat exchanger wall, so there is no mixing or contamination of the drinking water by the heating medium (which may contain corrosion inhibitors and other additives).

Heating is controlled by the boiler's regulation in cooperation with a temperature sensor (surface-mounted or immersed in the tank's pocket) and usually a three-way switching valve, which, upon a DHW demand, redirects the flow of heating water from the radiator circuit to the tank's heat exchanger. As a result, hot water preparation takes priority over space heating, and the household has hot water available practically immediately after the circulation pump starts.

The advantage of this solution over instantaneous heating (a combi boiler without a tank) is that the tank stores a supply of already heated water - so a larger amount of hot water can be drawn at once (for example, filling a bathtub) without the output limitation that instantaneous heating in a boiler has.

How to choose the right tank for your boiler

When choosing the volume of a Z-range tank (100, 125, or 160 litres), it is recommended to base the choice primarily on the number of people in the household and hot water consumption habits:

• 100 litres - suitable for 1-3 people, an apartment or smaller family house with standard consumption (showering, kitchen, bathroom without a bathtub or with occasional filling)
• 125 litres - suitable for 3-4 people, a typical family house, a combination of shower and bathtub
• 160 litres - suitable for 4-5 or more people, households with higher demand for simultaneous consumption (e.g. multiple bathrooms)

This particular model, the ATTACK Wall-mounted horizontal storage tank Z 160 OKCV - right, has a volume of 160 litres with a heat exchange area of 1.2 m². The larger the heat exchange area, the faster the tank can "recharge" consumed hot water at the same boiler output - when choosing between a standard and an "enlarged" heat exchanger (where both are manufactured, e.g. the OKC 125/160 range), also consider the output of your boiler: for boilers with higher output (25-30 kW), it is worth choosing the version with the larger heat exchanger so that its output can actually be used for fast DHW heating as well.

The tank itself does not generate heat - it must be connected to a suitable source, usually a stationary cast-iron gas boiler ATTACK (EKO COMBI, PLQ COMBI, KLQ COMBI, E COMBI, or EZ COMBI range), which has provision for connecting an external DHW tank via a three-way valve. These boilers themselves prepare DHW only instantaneously or not at all, and it is precisely the external Z-range tank that adds the hot water storage function to them. When combined with a heat pump or a solar system, we recommend choosing specialised HP or SOL range models (other products in our range), which have a heat exchanger sized for lower heat carrier temperatures.

Installation and connection

The horizontal tank is installed suspended - most often on two or four suspension rods, brackets, or straps anchored to the ceiling or a load-bearing structure, or above a wall-hung boiler in a shared frame. Before installation, it is necessary to verify the load capacity of the ceiling/structure with regard to the weight of the filled tank (empty weight approx. 41 kg + the weight of 160 l of water, i.e. an additional approx. 160 kg).

The cold and hot water connections, as well as the heat exchanger circuit, are located on the side corresponding to the ordered orientation (right-hand). We recommend fitting shut-off valves on all connections, a safety valve on the cold water inlet (sized according to applicable standards), and, in the case of harder water, also a softening or dosing system to extend the tank's service life. Installation should be carried out by an authorised person (heating engineer/plumber) in accordance with the manufacturer's installation manual and applicable legislation (in particular STN EN 12897 and related regulations for pressure vessels).

Maintenance and service

To ensure the ATTACK Wall-mounted horizontal storage tank Z 160 OKCV - right lasts as long as possible, we recommend following a regular service cycle:

• Checking the magnesium anode at least once a year (more often with harder water) - a worn anode must be replaced in time, otherwise it loses its protective function and corrosion of the tank accelerates from the inside
• Desludging/draining the tank via the drain valve once every 1-2 years, especially in areas with harder water, where limescale and sludge accumulate at the bottom of the tank
• Checking the safety valve on the cold water supply - regularly turning it to verify its function and the patency of the drip pipe
• Checking the tightness of connections and the heat exchanger at every annual boiler service inspection
• With hard water, consider installing a softening or dosing device, which significantly extends the service life of both the heat exchanger and the tank

Regular maintenance is also a condition for warranty recognition in the event of a fault caused by corrosion or limescale deposits.

Safety, standards, and legislation

The ATTACK Wall-mounted horizontal storage tank Z 160 OKCV - right is a pressure vessel that must be installed and operated in accordance with applicable technical standards and regulations, in particular STN EN 12897 (indirectly heated water heaters) and related regulations for pressure equipment. Correct installation always includes a properly sized safety valve on the cold water inlet, which protects the tank from excessive overpressure during heating - its discharge/drip pipe must be routed freely into a space with a fall and must not be shut off or blocked in any way.

We also recommend installing an expansion vessel on the cold water side (especially if there is a check valve or pressure reducing valve on the inlet that prevents water from flowing back into the water supply network during heating and thermal expansion). Without an expansion vessel, the safety valve may open repeatedly, causing unnecessary water loss.

Always entrust installation, connection to the boiler's heating circuit, and initial commissioning to a qualified person authorised to install gas and heating equipment. Only professionally performed installation and a regular annual service inspection (together with a boiler inspection) are also a precondition for warranty recognition in the event of a claim. The 160-litre tank is intended exclusively for heating drinking (domestic) water in the internal plumbing of buildings, not for other technological purposes.

Position in the ATTACK range

The ATTACK Wall-mounted horizontal storage tank Z 160 OKCV - right belongs to the Z range - indirectly heated DHW storage tanks of the ATTACK brand, which, besides this model, also includes other volumes (100, 125, 160, 200 litres), designs (stationary OKH NTR/HV, wall-mounted OKC, horizontal wall-mounted OKCV), and special variants (e.g. with an additional 2.2 kW electric element built into the tank body, a solar version SOL with two heat exchangers, or an HP version designed for heat pumps). Thanks to the wide range of variants, it is possible to find a tank precisely tailored to the boiler room layout and the household's needs.

We recommend combining this model primarily with stationary cast-iron gas boilers ATTACK of the EKO COMBI, PLQ COMBI, KLQ COMBI, E COMBI, and EZ COMBI ranges, which have provision for connecting an external DHW tank, since the boiler itself does not contain a DHW tank.

Frequently asked questions

Do I still need a boiler with the 160 l tank, or does it work on its own?

The ATTACK Wall-mounted horizontal storage tank Z 160 OKCV - right is an indirectly heated type - it does not generate heat on its own. It must always be connected to a heat source, most often a stationary ATTACK gas boiler with provision for an external DHW tank (via a three-way valve), or another suitable source with a sufficiently sized output.

Can the tank also be connected to a heat pump or solar collectors?

Yes, in principle it can, but we recommend the specialised HP range models (for heat pumps, large-area heat exchanger for a low-temperature source) or SOL (with an additional solar heat exchanger), which are directly sized for these sources. This Z-range model is primarily designed for a classic gas boiler.

How long does hot water stay hot in the tank without heating?

Thanks to the high-quality PUR insulation, standby losses are low, but the exact time depends on the room temperature and the difference compared to the water temperature. In general, under normal conditions, the tank keeps water at a usable temperature for several hours up to overnight; for a longer standby mode without the boiler, it is advisable to add the optional electric heating element.

Is it possible to purchase electric additional heating?

Yes, the tank has provision (a pocket/outlet) for an electric heating element with a thermostat, which is purchased separately (for example, output of 2-6 kW depending on the model). This allows DHW heating even outside the heating season, when the boiler is switched off.

What is the warranty on the tank?

We provide a 5-year warranty on the insulated tank and 24 months on other parts (e.g. anode, seals, accessories) from the date of shipping, provided the installation conditions and regular maintenance (in particular checking and replacing the anode) are observed.

How often does the magnesium anode need to be replaced?

We recommend checking the anode at least once a year during the boiler service inspection. With more aggressive or harder water, more frequent checks and an earlier replacement date may be necessary - a worn anode loses its anti-corrosion function.

What is the difference between the 100, 125, and 160-litre volumes?

The difference is mainly in capacity - a larger volume means more accumulated hot water available at once (e.g. when filling a bathtub while showering simultaneously), but also larger physical dimensions and weight. The choice depends on the number of people in the household and water consumption habits.

Why choose the horizontal OKCV design instead of an upright tank?

The horizontal design OKCV is suitable for spaces with low ceiling height, for example above a wall-hung boiler, in a suspended ceiling, or in a kitchen unit, where an upright tank would not fit or would unnecessarily take up floor space.

What is the difference between the right-hand and left-hand versions?

The right-hand/left-hand designation indicates the side on which the water and heat exchanger connections are located when viewed from the front of the tank. The choice depends on the direction of existing or planned pipework - we therefore recommend verifying this side directly at the installation site before ordering.

Warranty and service

For ATTACK brand products, we provide a 5-year warranty on the insulated tank (subject to compliance with installation conditions and regular maintenance, including checking and replacing the magnesium anode) and 24 months on other parts and accessories from the date of shipping from the factory. Service and spare parts (e.g. anodes, seals, accessories) are available in Slovakia. If you have any questions about choosing, installing, or making a claim, feel free to contact us - we will also be happy to advise on choosing a suitable boiler or controller for this tank.