Vaillant eloBLOCK VE 28/14 EU III electric boiler 28 kW

Product detailed description

Vaillant eloBLOCK VE 28/14 EU III is a powerful wall-mounted electric boiler with an output of 28 kW, designed for large family houses, guesthouses, commercial premises, or as a backup/supplementary source in a cascade for approx. 260 m² and more. It is the flagship, most powerful model of the entire eloBLOCK VE .. /14 EU III range, with sufficient power reserve even for more demanding heating seasons and lower outdoor temperatures, when a classic heat pump loses part of its output and efficiency.

The boiler is designed for installation into a heating circuit with radiators, underfloor heating, or a combination thereof, and by default includes everything needed for immediate connection - a highly efficient circulation pump, expansion vessel, safety valve, pressure gauge, thermometer, and a digital control and information system on the front panel. Thanks to this, installation is fast and does not require purchasing any additional components for the primary circuit.

Technical characteristics

The VE 28/14 model belongs to the Vaillant eloBLOCK VE .. /14 EU III range of electric boilers, which is manufactured in output levels from 6 to 28 kW - you choose exactly according to the heat loss of your building, so you don't pay for output you won't actually use, nor risk undersizing the heat source.

• Rated heating output - 28 kW, with the option of partial load at 1/2 or 1/3 output depending on current heat demand
• Electrical connection - 400 V / 50 Hz, three-phase connection, 50 A fuse protection
• Dimensions (H × W × D) - 740 × 410 × 310 mm (height × width × depth)
• Weight - approximately 35.4 kg
• Water volume in the boiler - 10 litres in the boiler body
• Expansion vessel - 7 litres, pressure 0.75 bar
• Maximum operating pressure - 3 bar
• Maximum adjustable heating water temperature - 70 °C
• Heating circuit connections - 3/4" for the heating circuit and also for potential DHW tank connection
• Protection rating - IP40
• Space heating energy class - D (space heating)
• Number of heating elements - 1 (with partial output switching)
• Integrated accessories - highly efficient circulation pump, expansion vessel, safety valve, pressure gauge, thermometer, flow temperature sensor, pressure sensor

The control electronics of the VE 28/14 boiler continuously evaluate the flow temperature and system pressure and switch between individual output levels of the heating element according to current demand - this means the boiler does not needlessly run at full output when half or one-third output is sufficient, saving electricity even during long-term operation. The boiler is intended exclusively for a closed heating circuit (not for instantaneous heating of drinking water) - however, in combination with an indirect DHW tank, it can fully provide domestic hot water heating for the household as well.

Installation and electrical connection

The VE 28/14 model connects to a three-phase 400 V/50 Hz supply, and the feed must be protected by a 50 A circuit breaker - the exact dimensioning of the supply cable and the type of breaker (characteristic B or C depending on the distribution network) must be designed and implemented by a qualified electrician with a valid inspection report, as this is an appliance with high current draw. We recommend consulting the dimensioning of the main protective element of the house (main breaker before the electricity meter) with the electricity distributor in advance, especially if you plan to combine the boiler with other large appliances (heat pump, cooker, electric vehicle charger).

During installation, it is also worth considering the following points:

• Using a low night tariff (dual tariff meter) - if the house has a dual-tariff meter with a ripple control relay installed, the boiler can use cheaper night-time electricity to heat the building's thermal mass or the DHW tank.
• Placing the boiler as close as possible to the heating circuit distribution to minimise heat losses in the piping and the length of the electrical supply.
• Ensuring sufficient space around the boiler for service access and ventilation of the boiler room.
• Adding a room thermostat or Vaillant weather-compensated control (e.g. sensoCOMFORT VRC 720 or VRT 350f) for more precise and economical temperature control in individual rooms.

Use, compatibility and control

The VE 28/14 electric boiler is fully compatible with common heating systems - radiators (panel or column type), underfloor heating, or a combination of both via a mixing station. The boiler can be complemented with an indirect hot water tank (for example the VIH or uniSTOR series) to create a complete source of heat and hot water for the household. The control system can be extended with room thermostats, weekly programmers, or modern weather-compensated control with a mobile app output, which evaluates the outdoor temperature and regulates the heating water temperature accordingly - this significantly increases comfort and operating savings.

Conversely, for smaller buildings we recommend looking at the eloBLOCK VE 24/14 model, which is sufficient for a smaller heated area at a lower purchase and operating cost.

The boiler is also suitable as:

• The main heat source in the absence of a gas connection or where the burning of solid fuels is prohibited in the given location.
• A supplementary/backup source alongside a heat pump, especially in a bivalent setup at very low outdoor temperatures.
• A temporary solution during renovation, until a gas connection or other permanent source is implemented.
• A solution for recreational properties - cottages and cabins, where consumption occurs only occasionally and investing in a gas connection would not be worthwhile.

Maintenance and service

The eloBLOCK VE 28/14 electric boiler is a virtually maintenance-free heat source compared to gas condensing boilers or solid fuel boilers - it contains no burner, flue, or chimney that would need to be regularly cleaned. Nevertheless, we recommend:

• Having a service inspection carried out once a year by a qualified technician - checking the tightness of the circuit, the function of the safety valve, the pressure in the expansion vessel, and the condition of the heating element.
• Monitoring the heating water pressure on the boiler's pressure gauge and, if it drops below the recommended value, topping up the system according to the instructions in the operating manual.
• In areas with harder water, consider treating the fill water (softening/demineralisation), which extends the life of the heating element and reduces the risk of scale deposits.
• Keeping the space around the boiler clear and not covering the ventilation openings of the casing.

Thanks to its simple construction and the absence of a combustion process, the service life of eloBLOCK series electric boilers is generally high and the failure rate low, which, combined with a 2-year warranty from the supplier WINTNER s.r.o., represents a safe and long-term investment.

Why choose the eloBLOCK VE 28/14

Vaillant is one of the most trusted heating technology brands in Europe, and the eloBLOCK range brings the same build quality to the electric boiler segment as you know from the ecoTEC gas condensing boilers. The VE 28/14 model with an output of 28 kW is the flagship, most powerful model of the entire eloBLOCK VE .. /14 EU III range, making it a well-considered choice for large family houses, guesthouses, commercial premises, or as a backup/supplementary source in a cascade for approx. 260 m² and more. The boiler arrives fully ready for connection, including the pump and all necessary accessories, so the electrician on site only needs to deal with connecting it to the mains and to the existing heating circuit.

When selecting the correct output, it is worth basing the decision on an actual calculation of the building's heat loss (or a designer's recommendation), not just on the approximate floor area - the quality of insulation, ceiling height, number and size of windows, and location all have a significant impact on the required output. If in doubt, we are happy to help you choose the right model from the entire eloBLOCK range and suggest suitable controls.

Comparison of the entire eloBLOCK VE .. /14 EU III range

The VE 28/14 model you are currently viewing is highlighted in the table below along with the rest of the eloBLOCK range. The table serves as a quick reference if you are not entirely sure whether the chosen output is the right one for your building - all models have the same body dimensions and the same basic equipment (circulation pump, expansion vessel, safety valve), differing in the output of the heating element, weight, and required fuse protection.

Approximate operating costs

The exact operating consumption of an electric boiler is primarily determined by the heat loss of the specific building, the quality of insulation, the set room temperature, and the length of the heating season - the following calculation is therefore only approximate and serves to give a rough idea. Assuming a model scenario of approximately 1700 hours of equivalent full-output operation during the heating season (typical for large family houses, guesthouses, commercial premises, or as a backup/supplementary source in a cascade for approx. 260 m² and more), the annual consumption of the VE 28/14 model would reach approximately 47,600 kWh, which, at current electricity prices ranging from approx. 0.18 - 0.28 €/kWh (depending on the tariff and supplier), represents approximate annual costs of around €8,568 - €13,328.

Actual consumption can be significantly reduced by using dual-tariff metering with a ripple control relay (shifting consumption to the cheaper night-time band), good building insulation, weather-compensated control based on outdoor temperature, and sensible setback of the temperature during absence or at night. We recommend consulting a heating designer or energy auditor for an accurate estimate of operating costs for your specific building.

Frequently asked questions