ATTACK Boiler Conversion Kit 25-35 DPX to COMBI Pellet with 30 kW Burner

Product detailed description

ATTACK Conversion Set for 25-35 DPX Boiler to COMBI Pellet with 30 kW Burner

The DPD30900 set allows for a subsequent conversion of the ATTACK 25-35 DPX Standard/Profi wood gasification boiler to fully automatic operation with wood pellet combustion. This is a proven solution for households that want to keep the advantages of the massive and durable cast-iron/steel boiler body of the ATTACK DPX Standard/Profi, while also gaining the comfort of automatic feeding without the daily operation typical of wood boilers.

The set includes a pellet burner with an output of 30 kW, a pellet storage tank, a fuel transport system (feeding system/hose depending on the specific tank design), and burner control electronics including connection to the existing boiler control system. After conversion, the boiler can be operated either exclusively on pellets, or in a combined mode, in which the original option of feeding wood as a backup fuel is retained (for example, in case of a pellet supply outage or power failure).

Compatibility

The DPD30900 set is intended exclusively for ATTACK 25-35 DPX Standard/Profi series boilers. Before ordering the set, it is necessary to report the serial number of the boiler to which the set will be fitted – based on the serial number, an ATTACK service technician will verify the exact design of the boiler (dimensions of the loading chamber, door type, control system revision) and prepare the corresponding components and mounting accessories. Installation of any combination of burner and boiler other than the specified one is not possible and could lead to incorrect combustion function or invalidation of the warranty.

How pellet combustion works in a converted boiler

After converting the 25-35 DPX Standard/Profi boiler using the DPD30900 set, the pellet burner takes over the supply and ignition of fuel. The burner automatically doses the precise amount of pellets from the storage tank into the combustion chamber using the feeding system (screw conveyor or pneumatic feeding depending on the specific tank design); the pellets are ignited by a glow coil and burned with precisely controlled air supply. The burner's control electronics continuously evaluate the required output according to the heating water temperature or room thermostat and smoothly adjust the amount of pellets dosed as well as the intensity of combustion air. Thanks to this, the boiler operates with high efficiency even at partial load, unlike manual wood heating, where output regulation depends on the operator and the manner of feeding.

Automatic pellet operation brings a fundamental difference in operating comfort compared to wood heating. While with a wood gasification boiler fuel must be fed manually (usually 1–2× daily depending on frost and the volume of the hopper), with pellet operation it is enough to periodically refill the pellet storage tank, with the interval between refills depending on the volume of the chosen tank and current consumption – with larger tanks, this can amount to weeks of operation without the need for operator intervention. This will be appreciated especially by households where it is not possible to feed fuel during the day (working owners, weekend cottages, elderly persons who are not physically capable of handling heavy wood logs).

Comparison of wood and pellet heating

The decision between keeping the boiler on wood heating and converting to pellets depends on several factors. Wood is generally a cheaper fuel per unit of heat produced, especially if the household has its own or a cheap source of firewood, but it requires physical work with feeding, storage, and preparation (cutting, splitting, drying). Pellets, on the other hand, are more expensive per unit of heat, but eliminate the work of feeding, simplify storage (bags or a large-volume tank instead of space for wood), and allow more precise output regulation thanks to automatic dosing. Combined operation after installing the DPD30900 set allows you to make use of the advantages of both fuels depending on the current situation – for example, heating with wood when the operator is present and has cheap wood available, and switching to automatic pellet operation during absence, vacation, or in periods when wood is not conveniently available.

Storage and refilling of pellets

Wood pellets must be stored in a dry environment protected from moisture – moisture causes pellets to disintegrate and degrade, losing their calorific value and potentially clogging the burner's feeding system. The storage tank supplied as part of the DPD30900 set can be refilled manually (bagged pellets) or, in some designs, connected to a larger external tank/silo to extend the interval between refills. We recommend choosing the tank volume according to the actual annual heat consumption of the building and the available space in the boiler room – an ATTACK sales or service representative will be happy to advise on tank capacity design.

Compatibility with the existing boiler control system

One of the main advantages of the DPD30900 set is the connection of the pellet burner's control unit with the original control system of the ATTACK 25-35 DPX Standard/Profi boiler via a connecting cable supplied as part of the set. Thanks to this, there is no need to change or add to the existing wiring of the heating system – the circulation pump, mixing circuit, and any room thermostat can continue to operate in the same configuration as before the conversion; the burner's control unit merely takes over the function of switching and regulating the heat source output. During installation, the service technician will also check and, if necessary, reprogram the parameters of the original boiler control system so that the two units work together without conflicts (for example, in controlling the circulation pump or signaling fault conditions).

Key features of the DPD30900 set

Why converting to pellets makes sense

• Automatic operation – the burner doses pellets from the storage tank automatically according to the demand from the control system, without the need for daily wood feeding.
• Preservation of the original boiler body – there is no need to replace the entire boiler, which saves costs compared to buying a new pellet boiler.
• Possibility of combined wood/pellet operation – it is possible to switch between automatic pellet combustion and manual wood feeding as needed.
• Suitable for both cottage owners and year-round living – especially appreciated by households that want to reduce the physical demands of heating with wood, but do not want to give up the possibility of heating with wood when it is available.
• Controlled burner output regulation according to current heat demand, which reduces pellet consumption compared to unregulated operation.

Technical data of the DPD30900 set

Detailed composition of the DPD30900 set

The conversion set is supplied as a complete package, which mainly includes the pellet burner itself with an output of 30 kW with a built-in ignition element (glow coil), the burner control unit with its own display and the ability to set operating parameters (power levels, cleaning cycles, time schedules), a pellet storage tank including a lid and a fuel level sensor, a feeding system (screw conveyor or hose feeder depending on the selected design), and mounting accessories needed to install the burner into the door or loading section of the boiler. The delivery also includes a connecting cable between the burner's control unit and the original boiler control system, which ensures that both devices work together as a single functional unit.

Burner service and maintenance

The pellet burner requires considerably less regular operation than classic wood feeding, but it is not completely maintenance-free. We recommend regularly (according to the operating manual, usually once every few weeks of operation) checking and cleaning the burner's combustion bowl of residual ash, which, if not cleaned sufficiently, can restrict the supply of combustion air and reduce the quality of combustion. At least once a year, before the heating season, we recommend having a service inspection of the burner performed by an authorized ATTACK technician, who will check the function of the ignition element, the tightness of the feeding system, the control system settings, and, if necessary, perform combustion calibration. Regular servicing extends the life of the burner and maintains the declared efficiency and low emissions of operation.

Economics and ecology of pellet operation

Wood pellets are among the renewable energy sources, usually produced from waste wood material (sawdust, wood shavings) by compression under high pressure without the addition of chemical binders. Burning pellets in a controlled burner with the DPD30900 set is therefore considered an environmentally friendly way of heating with low ash content and low emissions compared to uncontrolled wood combustion. From an economic point of view, the cost of heat from pellets is usually higher than from cheap own wood, but lower or comparable to heating with electricity or gas, with significantly higher operating comfort. We recommend assessing the exact return on investment in the conversion set individually, according to current fuel prices and the previous heating method of a particular household.

Installation and commissioning

Installation of the DPD30900 set, including connection to the existing boiler, setting up the burner control system, and initial commissioning, must be carried out exclusively by an authorized ATTACK service technician. During installation, the burner is installed into the loading or combustion section of the boiler according to the manufacturer's installation instructions, and it is also connected to the existing chimney draft and the electrical network. The recommendations applicable to the original boiler must continue to be observed – especially protection against low-temperature corrosion using a mixing circuit (min. 60 °C return temperature) and, ideally, the addition of a buffer tank, which evens out fluctuations in heat demand.

Before the actual installation, we also recommend considering the placement of the pellet storage tank in the boiler room so that convenient access is ensured for refilling (for example, close to a door or window in the boiler room for delivering bagged pellets). When planning the space, it is also advisable to allow for a reserve for possible future expansion with an external tank of a larger volume, should future consumption or operating comfort requirements increase.

Frequently Asked Questions

Is it necessary to provide the boiler's serial number when ordering?
Yes, the boiler's serial number is necessary to verify exact compatibility and to prepare the correct mounting components of the DPD30900 set.

Can the boiler still be heated with wood after conversion?
In most designs, yes – the boiler can be operated in a combined wood/pellet mode depending on current needs and fuel availability.

Who can install the set?
Installation and commissioning may only be carried out by an authorized ATTACK service technician, which is also a condition for maintaining the warranty on both the boiler and the set.

What type of pellets is suitable for the burner of the DPD30900 set?
We recommend high-quality certified wood pellets (e.g. ENplus A1) with low dust and ash content, which extends the life of the burner and reduces the need for cleaning.

Will the conversion affect the boiler's warranty?
Installation must be carried out by an authorized service according to the prescribed procedure so as not to affect the warranty of the boiler body. The original warranty conditions for the boiler (36 months from commissioning, or an extended 7-year warranty in case of protection against low-temperature corrosion) remain valid even after conversion, provided that the operating conditions continue to be observed.

Is a buffer tank necessary even with pellet operation?
A buffer tank is not as necessary with automatic pellet operation as it is with wood heating, but it still brings advantages in evening out heat demand and reducing the number of burner switching cycles.

Can the set later be moved to another boiler?
The DPD30900 set is manufactured and set up specifically for a particular boiler model range (25-35 DPX Standard/Profi) and, in some cases, also for a specific boiler serial number. Relocation to another type of boiler is not possible without the intervention of an ATTACK service technician, or it would require adaptation of the mounting components.

How often is it necessary to refill the pellet storage tank?
The refilling interval depends on the chosen tank volume, the output at which the burner operates, and the heat loss of the heated building. With larger tanks, refilling at intervals of several days to weeks is common, however each household will only determine the exact interval after the first season of actual operation.

Does the burner make noise during operation?
The pellet burner makes a slight hum during dosing and combustion (fan, feeding system), but the noise level is comparable to common automatic heating technologies and, with proper placement in the boiler room, does not present a problem for the household.

What happens in the event of a power outage?
The pellet burner and the feeding system both need electricity to operate, so in the event of a power outage the burner automatically stops dosing and burning fuel. If the boiler was left in a combined design, it is possible to temporarily switch to manual wood heating; for critical buildings, we recommend considering a backup power source (UPS), at least for the control electronics and circulation pump.

Related ATTACK boilers to which the DPD30900 set can be fitted

The DPD30900 set is intended for boilers from the range of ATTACK 25-35 DPX Standard/Profi wood gasification boilers, which can be found in the same category of the e-shop (Stationary boilers and tanks > Classic and gasification boilers > Attack). When selecting a specific boiler model, we recommend taking into account the calculated heat loss of the building and then choosing the corresponding output within the given range, to which this conversion set is fully compatible.

If you are still choosing a specific boiler and considering conversion to pellets already at the time of purchase, we recommend consulting this information directly with an ATTACK sales representative – some revisions of the boiler body and doors may have slightly different dimensions suitable for fitting the burner, so it is advisable to plan a possible future conversion already when choosing a specific model and its output range.

Warranty

The DPD30900 set is covered by a warranty according to the general warranty conditions of the manufacturer ATTACK, s.r.o. The boiler to which the set is fitted retains the original warranty conditions applicable to the DPX Standard/Profi gasification boilers – standard 36 months from commissioning (max. 42 months from dispatch), with the option of an extended 7-year warranty on the boiler body if permanent protection against low-temperature corrosion is ensured (mixing circuit min. 60 °C). Exact conditions can be found in the warranty certificate supplied with the set and the boiler.