ATTACK 30 EKO COMBI - stationary gas cast iron boiler 30 kW

Product detailed description

ATTACK COMBI - stationary cast-iron gas boiler

Stationary gas boilers with a cast-iron heat exchanger are among the most durable and longest-proven heating solutions on the market. Cast iron as an exchanger material is highly resistant to corrosion and thermal shock, and it tolerates less gentle operating conditions (frequent switching, fluctuating return water temperature) better than thin-walled steel or aluminium exchangers. Thanks to this, cast-iron boilers have long enjoyed a reputation as robust and reliable devices suitable not only for ordinary family houses but also for larger buildings, facilities, workshops, small businesses or multi-generational houses with higher heat demand.

Another advantage of the cast-iron body is easy maintenance and serviceability - a cast-iron exchanger is usually made up of individual sections (segments), which means that if one of them is damaged, only the affected section can be replaced instead of the entire exchanger. In the long run this can mean lower servicing costs compared to one-piece exchangers. The stationary design (a boiler standing on the floor, not wall-mounted) also simplifies installation for higher outputs and makes it easier to connect to a naturally draught chimney, which is commonly used in both older and newer boiler rooms.

The model you are currently viewing belongs to the ATTACK EKO COMBI range and is designed for a nominal heat output of 30 kW. It is a stationary gas boiler in COMBI version - in the context of this cast-iron ATTACK range this means that the boiler itself does not have its own (built-in) domestic hot water (DHW) preparation. To heat hot water, the boiler therefore needs to be supplemented with an external indirectly heated DHW storage tank (e.g. from the ATTACK Z-series - see the "How to connect" section below). This type of solution (boiler + separate storage tank) is common and proven especially where greater comfort is required at multiple hot water draw-off points at the same time, since storage water heaters can cover even a temporarily higher DHW demand better than instantaneous heating.

The ATTACK EKO COMBI range is the basic, entry-level line of ATTACK cast-iron stationary boilers. It is intended for customers looking for a simple, reliable and affordable heating solution for a family house or a smaller facility without unnecessary extra features. EKO COMBI builds on the proven design of the cast-iron exchanger and basic automation, which makes it one of the most accessible stationary cast-iron gas boilers in the ATTACK range. It is a choice for those who expect primarily functionality, long-term operational stability and low purchase costs, and who are willing to trade more advanced comfort features for a lower price.

Why a cast-iron exchanger and not a steel or aluminium one?

When choosing a stationary gas boiler, customers often ask why they should choose a cast-iron exchanger when cheaper steel or lighter aluminium solutions are also available on the market. The answer relates mainly to the long-term durability of the material. Cast iron has higher thermal inertia than thin-walled steel, which in practice means a calmer, less "nervous" combustion process and lower material stress during sudden changes in return water temperature (for example when a cold system starts up after a longer shutdown). At the same time, cast iron is naturally more resistant to condensation corrosion, which can gradually damage thin-walled steel exchangers under unsuitable operating conditions (long-term low return water temperature).

Another practical argument is the already mentioned sectional (segmented) construction. A cast-iron exchanger does not consist of a single piece but of several sections stacked on top of each other and joined by sealing gaskets. If one section were to become damaged over the years of operation (which is unlikely even with cast iron, but theoretically possible, for example due to mechanical damage or extreme neglect of maintenance), a service technician can replace only the affected section without having to replace the entire boiler body. With one-piece steel or aluminium exchangers, this option usually does not exist, and damage to the exchanger means replacing the entire boiler or at least the entire exchanger block.

The disadvantage of cast iron is its higher weight (see the approximate figure in the technical parameters table below) and a somewhat slower thermal response when starting up from a cold state - however, for a stationary boiler intended for long-term, mostly continuous operation (not frequent switching on/off as with a cottage used a few times a year), these are rather marginal disadvantages compared to the benefit of a long service life and easier repairability.

Who is this boiler suitable for

The ATTACK EKO COMBI stationary cast-iron boiler with an output of 30 kW is a suitable choice primarily where a boiler room is available (it is not designed to be wall-mounted like common wall-hung combi boilers) and where a naturally draught chimney is available or planned. Typically this includes:

• Family houses with their own boiler room or utility room, where a long service life and easy serviceability of the equipment matter
• Larger buildings and multi-generational houses with higher heat demand, where the robustness of the cast-iron body is appreciated
• Smaller facilities, workshops, guesthouses or cottages with year-round or almost year-round operation, where the investment in a higher-quality body pays off over a longer service life
• Renovations where an older cast-iron boiler is being replaced and an existing chimney and gas supply sized for the given output are available

On the other hand, if you are looking for a compact wall-mounted solution for an apartment or a smaller housing unit, or a boiler with its own fast hot water preparation without the need for a separate storage tank, a stationary cast-iron COMBI boiler is probably not the most suitable choice - in that case we recommend consulting us about a more suitable alternative from the ATTACK wall-hung condensing boiler range.

Key features

• Stationary (floor-standing) design with a cast-iron heat exchanger - high resistance to corrosion and thermal shock
• Nominal heat output of 30 kW, fuel natural gas (LPG version on request/according to specific order specification)
• COMBI version = boiler without its own DHW preparation, designed to work together with an external indirectly heated storage tank (e.g. ATTACK Z-series)
• Sectional (segmented) cast-iron exchanger - in case of damage allows replacement of a single section instead of the entire body
• Connection to a naturally draught chimney (atmospheric combustion)
• Robust construction suitable also for larger buildings and facilities with higher heating output requirements
• Basic, proven equipment without unnecessary extras - emphasis on simplicity and low purchase price
• The delivery includes the boiler body itself, including the burner and basic control - the external DHW storage tank, circulation pump, expansion vessel, chimney accessories and room thermostat are not included in the basic price unless explicitly stated

Technical parameters

Note: dimensions and weight are given as an approximate estimate based on the output category and the usual construction of cast-iron sectional boilers of this class - we recommend verifying the exact value for a specific unit in the manufacturer's current technical data sheet or directly with us before ordering, especially if you are planning precise construction preparation of a room or recess for the boiler.

How to connect: boiler + external DHW storage tank

Because this is a COMBI version without its own domestic hot water preparation, this boiler needs to be connected together with a separate (external) indirectly heated DHW storage tank. For this purpose, the ATTACK range offers the so-called Z-series of storage tanks (e.g. Z100PLUS, Z125PLUS, Z100NTR, Z125NTRA, Z160NTRA, Z125OKC, Z160OKC, Z200OKC and other versions including OKCV horizontal wall-mounted variants) - we sell these storage tanks as a separate product; they are not included in the boiler's delivery or price.

For this higher output level (24-30 kW), typically used for larger households or smaller facilities with higher hot water consumption, we recommend considering a larger-capacity storage tank, e.g. ATTACK Z 160 OKC/NTR/HV or Z 200 OKC, or consulting the exact volume based on the actual number of draw-off points and peak DHW consumption.

The connection principle is briefly as follows: the boiler heats the heating water, which circulates both into the heating system (radiators, underfloor heating) and through the coil in the DHW storage tank, where it transfers heat to the domestic water. Switching between the heating circuit and heating the storage tank is usually handled by a three-way valve (in the ATTACK range, e.g. models OT02 or OT44), controlled either by the boiler's electronics or by a separate room thermostat/controller. The exact connection (pipe routing, placement of pumps, safety and mixing fittings) depends on the specific boiler room layout and on whether it is a simple two-pipe system or a more complex system with multiple heating circuits - we recommend having the final connection designed and carried out by an authorised heating/gas specialist who will also take into account locally applicable standards and regulations for connecting a gas appliance.

When ordering the boiler and the storage tank, we will be happy to help you choose a suitable combination of boiler output and storage tank volume according to the number of people in the household and the number of hot water draw-off points used simultaneously - do not hesitate to contact us before purchase if you are not sure about the right choice.

Maintenance and servicing in practice

As with any gas appliance, the ATTACK stationary cast-iron boiler also requires a regular service inspection (usually once a year, carried out by an authorised service technician), which is not only a condition for maintaining the warranty but, above all, a prerequisite for safe and economical operation. For cast-iron boilers, servicing usually includes checking and, if necessary, cleaning the exchanger and burner of soot and dust, checking the tightness of the joints between individual sections, checking the chimney draught and the flue gas path, and verifying correct combustion settings.

Compared to modern condensing boilers, maintenance of an atmospheric cast-iron boiler is usually simpler and cheaper - for example, there is no need to take care of a condensate siphon or an exchanger sensitive to low return water temperature. On the other hand, keep in mind that atmospheric cast-iron boilers of this construction do not achieve the efficiency of the most modern condensing solutions, which is a common and fair trade-off between higher initial robustness/simplicity and the highest possible energy efficiency. If the lowest possible gas consumption at any cost is a decisive criterion for you, we will be happy to discuss alternatives from the ATTACK condensing range with you as well.

Frequently Asked Questions

1. Is hot water (DHW) heating included in the price of this boiler?
No. This is a COMBI version without its own DHW preparation - the boiler only heats the heating water. To heat domestic hot water, an external indirectly heated storage tank (e.g. from the ATTACK Z-series) needs to be added, which is ordered and paid for separately.

2. Which DHW storage tank is suitable for a boiler with 30 kW output?
For this higher output level (24-30 kW), typically used for larger households or smaller facilities with higher hot water consumption, we recommend considering a larger-capacity storage tank, e.g. ATTACK Z 160 OKC/NTR/HV or Z 200 OKC, or consulting the exact volume based on the actual number of draw-off points and peak DHW consumption.

3. How does the EKO COMBI range differ from other ranges in the ATTACK COMBI cast-iron lineup (EKO, PLQ, KLQ, E, EZ)?
In short: it is the basic, entry-level range in the ATTACK cast-iron boiler lineup - simpler equipment, lower purchase price, suitable for customers who prefer functionality and price over additional comfort.

4. What type of fuel is the boiler designed for, and can it be converted to another fuel?
In its basic version the boiler is designed for natural gas. An LPG (propane-butane) version is available on request/according to specific order specification - we recommend stating this requirement when ordering or checking in advance with our sales team.

5. What warranty applies to this boiler?
ATTACK stationary gas boilers are covered by a 30-month warranty from commissioning, but no more than 36 months from the date of dispatch from the manufacturer's warehouse. An extended 5-year warranty applies to the cast-iron exchanger body. The exact warranty conditions are governed by the warranty certificate attached to the specific unit, and the prescribed commissioning conditions must be met (usually by a qualified service technician).

6. Can the boiler be connected to an existing naturally draught chimney?
Yes, it is an atmospheric boiler designed to be connected to a naturally draught chimney. The suitability of a specific chimney (diameter, height, material) needs to be assessed individually, ideally during a site inspection or in cooperation with a chimney sweep/inspection technician, especially if the boiler is being connected to an older brick chimney.

7. Can the boiler be connected to a system with multiple heating circuits (e.g. radiators + underfloor heating)?
Yes, combining multiple circuits with different heating water temperatures is common - however, it requires adding a mixing circuit with its own pump and control (in the ATTACK range, e.g. sets DPP25007/DPP25008 or ESBE versions DPP25020-DPP25022). We recommend discussing the connection design with a heating engineer or directly with our team.

8. Can the boiler be ordered without a DHW storage tank, just the body itself?
Yes - this product represents the boiler body itself. The DHW storage tank, circulation pump, chimney accessories, three-way valve and room thermostat/controller are ordered as separate items according to the needs of the specific installation - we will be happy to prepare a complete list of the accessories required, tailored to your project.

9. What is the difference between this atmospheric cast-iron boiler and a modern condensing boiler?
An atmospheric cast-iron boiler operates with a higher flue gas temperature and does not use condensation of water vapour from the flue gas for additional heat gain, so its efficiency does not reach the values of modern condensing boilers. In exchange, it offers a simpler construction, lower sensitivity to the return heating water temperature and usually simpler, cheaper maintenance without the need to deal with condensate drainage. The choice between a cast-iron atmospheric and a condensing solution is always a trade-off between initial robustness/simplicity and the highest achievable efficiency - we will be happy to help you weigh both directions according to your priorities.

10. Where can I order the boiler and how does delivery work?
You can order the boiler directly through the atria.sk online shop. When ordering, we recommend also considering a suitable DHW storage tank from the Z-series and any additional accessories (chimney parts, three-way valve, circulation pump, room thermostat) at the same time, so that you have a complete solution ready for installation. If you are unsure when choosing the combination of boiler + storage tank + accessories, do not hesitate to contact us before ordering - we will be happy to advise you so that you do not order something you will not ultimately need, or conversely, so that nothing essential is missing.

Warranty and service

ATTACK EKO COMBI stationary cast-iron gas boilers are covered by a standard warranty of 30 months from the boiler's commissioning, but no more than 36 months from the date of dispatch from the manufacturer's warehouse (whichever occurs first). The manufacturer provides an extended 5-year warranty on the cast-iron exchanger body itself. To claim the full warranty period, the commissioning conditions set by the manufacturer must be met (usually by a qualified service technician authorised for this activity), and a proper service book/warranty certificate must be kept. If you have any questions about the warranty, servicing, or choosing suitable accessories (DHW storage tank, circulation pump, chimney parts, controls), do not hesitate to contact us - we will be happy to help you choose and order a complete solution tailored to your needs.