Product detailed description

ATTACK Heating Circulation Pump 25/6, 130 mm, Class A

Universal electronic circulation pump of class A with an overall length of 130 mm – a shorter, more compact variant of the 25/6 pump designed for installations with a shorter port spacing, typical especially for more compact wall-mounted boilers and some ATTACK boiler ranges. Thanks to electronic power regulation, it offers the same comfort and efficiency as the 180 mm variant, only in a more space-saving design.

It is a versatile solution for service technicians and installers who need a compact class A pump for the main or mixing circuit without being tied to one specific brand – all that matters is that the 130 mm port spacing and the 1½" thread match.

Energy Class A – What It Really Means for Your Wallet

European legislation (the ErP Directive / EU Regulation No. 622/2012) defines an Energy Efficiency Index (EEI) for circulation pumps instead of the old letter classes A – G, but in everyday communication the term "class A" is still used for the most efficient pumps with EEI ≤ 0.20. This pump meets this value thanks to a wet-rotor motor with permanent magnets and electronic speed control, which continuously evaluates the pressure differential in the circuit and adjusts the output exactly according to need – not according to a fixed setting.

In practice, this brings two effects at once: lower electricity consumption (typically a few watts instead of several dozen watts with older three-speed pumps) and smoother, quieter operation without over-regulating the circuit. If your boiler or manifold has so far been running an old unregulated pump, replacing it with this model can reduce the annual electricity consumption for circulating heating water by tens to hundreds of kilowatt-hours, depending on the length of the heating season and the size of the circuit.

It's also worth remembering that an electronically regulated pump indirectly protects the heating system itself – thanks to smooth power regulation, the noise of flow in thermostatic valves is reduced, and wear on the bearings and seal is decreased, since the pump doesn't needlessly operate at an extreme output point.

How to Choose the Correct Overall Length – 130 mm or 180 mm

For circulation pumps, the "overall" or "installation" length refers to the distance between the axes of both connection ports of the pump. This value is not a matter of choice based on output, but must exactly match the already existing port spacing in the boiler or piping – it is therefore a purely dimensional, not a performance, parameter.

The most reliable approach when choosing a replacement is to remove the original pump and physically measure the distance between the centers of its two connection ports using calipers or a tape measure. If the pump has not yet been removed, the dimension can also be verified from the type designation on the label (manufacturers commonly state the length directly in the model designation, for example as "-130" or "-180" at the end of the type code).

For service work on ATTACK boilers, we always recommend stating the exact serial (manufacturing) number of the boiler before ordering – this makes it possible to clearly verify which overall length and exact pump type was factory-fitted in that particular boiler, since component suppliers may have changed over the course of production runs even within the same boiler output range.

The connection threads of both length variants are standardized to a 1½" internal thread with a union nut, so there is no difference between the 130 mm and 180 mm version in terms of the pipe connection itself – the only difference is the distance between the two ports.

When to Choose the 130 mm Variant

The 130 mm overall length is generally used where there is less installation space available between the ports – typically in more compact wall-mounted boilers, some built-in assemblies, or ATTACK boilers that use this shorter overall length by design. Replacing it with the longer 180 mm variant is not possible without modifying the piping, so it is essential to verify the actual port spacing before ordering.

• main heating circuit in more compact assemblies,
• mixing circuit with limited installation space,
• replacement for an older pump of another brand with the same 130 mm overall length,
• service replacement on ATTACK boilers originally fitted with a 130 mm pump (verify using the boiler's serial number).

Technical Parameters

• Overall (installation) length: 130 mm
• Energy class: A (EEI ≤ 0.20)
• Electrical power input: 3 – 45 W, continuously regulated
• Maximum head: 6 m
• Maximum flow rate: up to 3.5 m³/h
• Connection: 1½" internal thread, union nut
• Medium temperature range: 2 – 110 °C
• Power supply: 230 V / 50 Hz, protection rating IP44

How to Read the Circulation Pump's Type Label

The type label is affixed directly to the body of the pump's electronic head and contains all the information needed for unambiguous identification when ordering a replacement. Besides the manufacturer's type designation (e.g. RS 25/6, Yonos PARA RS25/6), you will also find the overall length there (often directly in the number after the slash or in a note below the type), the supply voltage range, maximum power input, IP protection rating, and the serial/manufacturing number of the specific unit.

If the label is already illegible (for example, after years of operation in the humid environment of a boiler room), the most reliable option is to directly measure the overall length with calipers, or contact our customer service with the serial number of the ATTACK boiler itself – from this we can determine which pump was fitted to that boiler at the factory.

When It's Time to Replace the Circulation Pump

The circulation pump is one of those components that usually don't fail suddenly, but whose performance and reliability gradually deteriorate over the years of operation. Here are a few symptoms to watch out for:

• Uneven heating – some radiators or circuits are noticeably cooler than others even with thermostatic heads fully open, which may indicate insufficient pump head.
• Increased noise – buzzing, squeaking, or knocking during operation that doesn't disappear even after thoroughly bleeding the circuit usually indicates worn bearings.
• Frequent thermal fuse trips or outages – may indicate mechanical seizing of the rotor or an electrical fault in the motor winding.
• Visible leakage at joints or around the shaft – after years of operation, the seal or gasket may wear out.
• High electricity consumption compared to the declared values – an older unregulated pump without class A may consume several times more energy than a modern electronically controlled solution.

If any of these symptoms occur, we recommend replacing the pump before it fails completely, which could cause the boiler to overheat or a heating outage at the most inconvenient moment of the heating season.

Practical Installation Guide

Replacing a circulation pump is a routine service task that an experienced heating technician or service engineer can complete in less than an hour if the correct procedure is followed:

1. Securing the circuit. Close the supply and return lines using shut-off valves (if these are not fitted, we recommend adding them at this opportunity – they will significantly simplify future servicing), and drain the water from the relevant section into a suitable container.
2. Removing the original pump by loosening both union nuts and taking it out of the pipe run, including the old gaskets.
3. Checking the flow direction marked with an arrow on the body of the new pump – it must match the direction of heating water flow at that point in the circuit.
4. Fitting new gaskets and screwing in the pump, making sure the electronic head remains in a horizontal position after tightening (never with the terminal box facing downward), to prevent moisture from getting into the electronics.
5. Filling the circuit and thoroughly bleeding it – air in the pump is the most common cause of noise and reduced performance immediately after installation.
6. Test run while checking the tightness of the joints, noise level, and the pump's response to a change in the circuit's thermal load (e.g. by closing part of the thermostatic heads).

Leave the electrical connection to the 230 V mains to a qualified person – incorrect wiring can damage the pump's electronics and is also a safety risk.

Maintenance and Extending the Pump's Service Life

Electronically controlled circulation pumps of this category are practically maintenance-free – they contain no lubrication points or parts requiring regular servicing beyond a routine check. Nevertheless, a few simple habits will significantly extend their service life and maintain the declared class A energy efficiency throughout their operating life:

• Heating water quality. Excessive sludge, rust, or air in the heating circuit is the most common cause of premature wear on the impeller and bearings of the wet-rotor motor. For older or recently piped systems, consider installing a dirt filter or a sludge separator upstream of the pump.
• Regular visual inspection. Once per heating season, check the tightness of the connections, the absence of corrosion traces on the pump body, and any unusual noises (buzzing, knocking), which may indicate air in the system or an incipient bearing fault.
• Brief shutdown outside the season. If the pump is not operating for a long period (e.g. outside the heating season in systems without year-round circulation), it is recommended to briefly run it occasionally to prevent the rotor from "seizing" due to deposits after prolonged inactivity – most modern pumps handle this automatically via a built-in permanent self-test function.
• Frost protection. In unheated spaces (e.g. shut-down cottages, technical rooms without heating), if there is a risk of frost, either ensure the circuit is drained or use an antifreeze mixture with declared compatibility with the pump's materials.

Safety Notices

Before any intervention on the pump, always disconnect the 230 V power supply and wait until the pump body has sufficiently cooled down – heating water can reach temperatures close to 90 °C, posing a risk of burns. The electrical connection must only be carried out by a person with appropriate electrotechnical qualification in accordance with applicable standards (STN 33 2000 and related). The pump is not designed for operation outside the declared medium temperature and pressure range stated in the technical parameters – exceeding these limits may damage the pump and endanger operational safety.

Frequently Asked Questions

How do I know if my ATTACK boiler needs a 130 mm or 180 mm pump?
Most reliably by measuring the distance between the centers of the original pump's ports, or by contacting our customer service with the boiler's serial number.

Is the 130 mm version less powerful than the 180 mm one?
No, both variants (OT01B and OT01C) have identical hydraulic parameters – the same maximum head and flow rate. They differ solely in overall length, not in performance.

Can I use the 130 mm pump with a reducer instead of the 180 mm one?
We do not recommend this – extending the length using incorrect connecting parts increases the risk of leaks and pipe stress. Always use a pump with the correct overall length.

What is the difference compared to the OEM WILO Yonos PARA 130 mm (OT130A)?
These are functionally very similar but distinct manufacturing designs – the OT130A is an original part identical to the one factory-fitted in selected ATTACK boiler ranges, while this pump is a universal alternative suitable for a wider range of installations.

Can the pump be serviced, or is a complete replacement necessary in case of a fault?
Electronic circulation pumps of this category generally cannot be repaired (they are a sealed wet-rotor unit); in case of a fault, the entire unit is replaced.

Is the necessary installation material included in the package?
Yes, the pump is supplied with union nuts and gaskets for standard connection to a 1½" thread.

Does the pump work at lower flow rates in summer (e.g. only for DHW reheating)?
Yes, thanks to electronic regulation the output automatically adapts even to low flow rates, minimizing electricity consumption outside the main heating season.

Can the pump be installed with the head facing upward in a vertical pipe as well?
Yes, in a vertical pipe the pump is installed by turning the pump body to the side so that the electronic head remains in a horizontal position – a vertical head position (up or down) is not recommended.

How long does a routine service replacement of this pump take?
With the tools and shut-off valves ready and an experienced technician, this is usually a job taking 30 to 60 minutes, including draining and refilling the relevant section of the circuit.

Do I need to state the type of heating medium when ordering?
For standard heating water or a common water-glycol mixture up to the recommended concentration, this is not necessary. For unusual media or chemical additives in the circuit, we recommend consulting compatibility with our customer service in advance.

Overview of Related Circulation Pumps in the ATTACK Range

Our range also includes other variants of class A circulation pumps, which differ in overall length or the degree of originality of the part compared to the factory-fitted units in ATTACK boilers:

• ATTACK PR 25/6, 180 mm – a longer universal variant with the same hydraulic parameters, for installations with a 180 mm port spacing.
• ATTACK WILO Yonos PARA RS25/6 Pump, 130 mm – an original OEM part of the same overall length, recommended for warranty service of ATTACK boilers.
• ATTACK Spare Part - RS 25/6 Pump, 130 mm – a more economical service alternative of the same overall length for post-warranty replacements.

Summary

The ATTACK 25/6, 130 mm is a compact, energy-efficient choice for installations with shorter port spacing. Before ordering, always verify the actual overall length of the original pump to avoid the need for an additional replacement.

Warranty and Support

We provide a warranty of 24 months from the date of dispatch from the warehouse for this product. The warranty covers manufacturing and material defects, provided the installation and operating conditions stated in the enclosed manufacturer's manual are observed. If you have any questions about selecting, compatibility, or installing the pump, do not hesitate to contact our customer service – we will be happy to help identify the correct type based on the serial number of your ATTACK boiler or the parameters of your heating circuit.

We recommend keeping the proof of purchase and, in case of a service intervention on the ATTACK boiler, also stating the type designation and serial number of the boiler – this will speed up any warranty claim process as well as the future identification of spare parts.