Vaillant eloBLOCK VE 18/14 EU III electric boiler 18 kW

Product detailed description

Vaillant eloBLOCK VE 18/14 EU III is a wall-mounted electric boiler with an output of 18 kW, which covers heating and heat preparation for larger family houses up to approx. 170-190 m² or houses with higher heat loss. It is a transitional model between a common home installation and larger buildings with higher consumption. The boiler replaces a conventional gas or solid fuel boiler where gas is not available, or serves as a modern replacement for a worn-out older electric boiler when reconstructing a boiler room.

The boiler is designed for installation into a heating circuit with radiators, underfloor heating or a combination of both, and by default includes everything needed for immediate connection - a high-efficiency 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 quick and does not require purchasing any additional components for the primary circuit.

Technical characteristics

The model VE 18/14 belongs to the Vaillant eloBLOCK VE. /14 EU III range of electric boilers, which is manufactured in power stages from 6 to 28 kW - you choose exactly according to the heat loss of your building, so that you neither pay for output you will not actually use, nor risk undersizing the heat source.

• Rated heating output - 18 kW, with the option of partial loading at 1/2 or 1/3 of output depending on current heat demand
• Electrical connection - 400 V / 50 Hz, three-phase connection, 32 A circuit breaker
• Dimensions (H × W × D) - 740 × 410 × 310 mm (height × width × depth)
• Weight - approximately 34.6 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 a possible connection of a DHW cylinder
• Protection rating - IP40
• Energy class for space heating - D (space heating)
• Number of heating elements - 1 (with partial output switching)
• Integrated accessories - high-efficiency circulation pump, expansion vessel, safety valve, pressure gauge, thermometer, flow temperature sensor, pressure sensor

The control electronics of the VE 18/14 boiler continuously evaluate the flow temperature and system pressure, and switch between individual output stages of the heating element according to current demand - thanks to this, the boiler does not work needlessly at full output if half or a third of the output is sufficient, which saves electrical energy 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 cylinder, it can also fully provide domestic hot water heating for the household.

Installation and electrical connection

The model VE 18/14 is connected to three-phase voltage 400 V/50 Hz, with the supply requiring protection by a 32 A circuit breaker - the exact dimensioning of the supply cable and the type of circuit breaker (characteristic B or C according to the distribution network) must be designed and carried out 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 circuit 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, stove, electric vehicle charger).

When installing, we also recommend considering these points:

• Using a low night tariff (dual tariff) - if the house has a dual-tariff electricity meter with a relay installed, the boiler can use cheaper night-time electricity to heat up the building's thermal mass or the DHW cylinder.
• 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 18/14 electric boiler is fully compatible with common heating systems - radiators (panel and towel rail types), underfloor heating and a combination of both via a mixing station. The boiler can be supplemented with an indirect hot water cylinder (for example the VIH or uniSTOR range) to create a complete source of heat and hot water for the household. Control 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.

If you are not sure whether the 18 kW output will be sufficient for your building, our range also includes the higher-output model eloBLOCK VE 21/14. On the other hand, for smaller buildings we recommend looking at the eloBLOCK VE 14/14 model, which is sufficient for a smaller heated area at a lower purchase and operating cost. Intermediate outputs such as VE 12/14 are also available, in case your heat loss does not exactly match any of the edge outputs.

The boiler is also suitable as:

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

Maintenance and service

The eloBLOCK VE 18/14 electric boiler is a 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 performed 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 build-up.
• Keeping free space around the boiler and not covering the ventilation openings of the casing.

Thanks to the simple construction and the absence of a combustion process, the lifespan of electric boilers in the eloBLOCK range is generally high and the failure rate low, which, combined with a 2-year warranty, represents a safe and long-term investment.

Why choose the eloBLOCK VE 18/14

Vaillant is one of the most trusted heating technology brands in Europe, and the eloBLOCK range brings the same quality of workmanship to the electric boiler segment that you know from the ecoTEC gas condensing boilers. The VE 18/14 model with an output of 18 kW is a transitional model between a common home installation and larger buildings with higher consumption, making it a well-considered choice for larger family houses up to approx. 170-190 m² or houses with higher heat loss. The boiler arrives fully ready for connection, including the pump and all necessary accessories, so the electrician on site only needs to handle the connection to the electrical grid and to the existing heating circuit.

When choosing 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 an approximate 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 will gladly help you choose the right model from the entire eloBLOCK range as well as suggest a suitable control system.

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

The VE 18/14 model, which 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 completely sure whether the selected 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 circuit breaker rating.

Estimated operating costs

The exact operating consumption of an electric boiler is always determined primarily 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 as a rough guide. Assuming a model scenario of approximately 1500 hours of equivalent operation at full output during the heating season (common for larger family houses up to approx. 170-190 m² or houses with higher heat loss), the annual consumption of the VE 18/14 model would reach approximately 27,000 kWh, which at current electricity prices ranging from approx. €0.18 - €0.28/kWh (depending on the tariff and supplier) represents estimated annual costs of approximately €4,860 - €7,560.

Actual consumption can be significantly reduced by using dual-tariff metering (shifting consumption to the cheaper night-time band), quality insulation of the building, weather-compensated control based on outdoor temperature, and reasonable setting of temperature setback 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