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Comparison Vaillant ecoTEC plus VU 15CS/1-5 16.4 kW vs Vaillant ecoTEC pure VUW 246/7-2 18.5 kW

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Vaillant ecoTEC plus VU 15CS/1-5 16.4 kW
Vaillant ecoTEC pure VUW 246/7-2 18.5 kW
Vaillant ecoTEC plus VU 15CS/1-5 16.4 kWVaillant ecoTEC pure VUW 246/7-2 18.5 kW
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Main
Modern control panel with touch screen and setting assistant. System of automatic make-up and pressure control. Three-way valve for connecting an indirect heating boiler. Possibility of connection of the gateway for management through the Internet.
Energy sourcegasgas
Installationwallwall
Typesingle-circuit (heating only)dual-circuit (heating and DHW)
Heating area131 m²148 m²
Condensing
Technical specs
Heat output16.4 kW18.5 kW
Min. heat output2.8 kW6.5 kW
Power supply230 V230 V
Power consumption75 W100 W
Coolant min. T30 °С30 °С
Coolant max. T85 °С80 °С
Heating circuit max. pressure3 bar3 bar
DHW circuit max. pressure10 bar
Consumer specs
DHW min. T35 °С
DHW max. T60 °С
Performance (ΔT ~30 °C)9.9 L/min
"Summer" mode
Warm start
Circulation pump
Control buseBus
Programmable thermostat
Boiler specs
Efficiency105.7 %
Combustion chamberclosed (turbocharged)closed (turbocharged)
Flue diameter60/100 mm60/100 mm
Inlet gas pressure13 mbar20 mbar
Max. gas consumption2.2 m³/h2.6 m³/h
Expansion vessel capacity10 L
Expansion vessel pressure1 bar
Coolant performance636 L/h
Heat exchangerstainless steelstainless steel
Connections
Mains water intake3/4"
DHW flow3/4"
Gas supply1/2"1/2"
Central heating flow3/4"3/4"
Central heating return3/4"3/4"
Safety
Safety systems
gas pressure drop
water overheating
flame loss
draft control
water circulation failure
frost protection
gas pressure drop
water overheating
flame loss
draft control
water circulation failure
frost protection
More specs
Dimensions (HxWxD)720x440x348 mm720x440x372 mm
Weight34 kg33.5 kg
Added to E-Catalogaugust 2021june 2017

Type

Depending on the set of functions, boilers are divided into single-circuit and dual-circuit.

- Single-circuit boilers are equipped with one heat exchanger, in which the heat from fuel combustion is transferred to the heat medium of the heating system. The only function of such boilers is space heating. It is technically possible to use single-circuit boilers to provide hot water, but this requires an additional tank (the so-called indirect water heater).

- In dual-circuit boilers, the primary heat exchanger is supplemented by a secondary one. Due to this, such a boiler, in addition to heating the room, also provides a hot water supply. In this case, both running water and water accumulated in a special tank(see Built-in water heater tank) can be used.

Heating area

A very conditional parameter that slightly characterizes the purpose based on the size of the room. And depending on the height of the ceilings, layout, building design and equipment, actual values may differ significantly. However, this item represents the maximum recommended area of the room that the boiler can effectively heat. However, it is worth considering that different buildings have different thermal insulation properties and modern buildings are much “warmer” than 30-year-old and especially 50-year-old houses. Accordingly, this item is more of a reference nature and does not allow us to fully assess the actual heated area. There is a formula by which you can derive the maximum heating area, knowing the useful power of the boiler and the climatic conditions in which it will be used; For more information on this, see "Useful Power". In our case, the heating area is calculated using the formula “boiler power multiplied by 8”, which is approximately equivalent to use in houses that are several decades old.

Heat output

It is the maximum useful power of the boiler.

The ability of the device to heat a room of a particular area directly depends on this parameter; by power, you can approximately determine the heating area, if this parameter is not indicated in the specs. The most general rule says that for a dwelling with a ceiling height of 2.5 – 3 m, at least 100 W of heat power is needed to heat 1 m2 of area. There are also more detailed calculation methods that take into account specific factors: the climatic zone, heat gain from the outside, design features of the heating system, etc.; they are described in detail in special sources. Also note that in dual-circuit boilers (see "Type"), part of the heat generated is used to heat water for the hot water supply; this must be taken into account when evaluating the output power.

It is believed that boilers with a power of more than 30 kW must be installed in separate rooms (boiler rooms).

Min. heat output

The minimum heat output at which the heating boiler can operate in constant mode. Operation at minimum power allows you to reduce the number of on-and-off cycles that adversely affect the durability of heating boilers.

Power consumption

The maximum electrical power consumed by the boiler during operation. For non-electric models (see Energy source), this power is usually low, as it is required mainly for control circuits and it can be ignored. Regarding electric boilers, it is worth noting that the power consumption in them is most often somewhat higher than the useful one since part of the energy is inevitably dissipated and not used for heating. Accordingly, the ratio of useful and consumed power can be used to evaluate the efficiency of such a boiler.

Coolant max. T

The maximum operating temperature of the heat medium in the boiler system when operating in heating mode.

DHW circuit max. pressure

The maximum pressure in the hot water circuit (DHW) at which it can operate for a long time without failures and damage. See "Heating circuit maximum pressure".

DHW min. T

The minimum temperature of domestic hot water (DHW) supplied by a dual-circuit boiler. For comparison, we note that water begins to be perceived as warm, starting from 40 °C, and in centralized hot water supply systems, the temperature of hot water is usually about 60 °C (and should not exceed 75 °C). At the same time, in some boilers, the minimum heating temperature can be only 10 °C or even 5 °C. A similar mode of operation is used to protect pipes from freezing during the cold season: the circulation of water with a positive temperature prevents the formation of ice inside and damage to the circuits.

It is also worth keeping in mind that when heated to a given temperature, the temperature difference ("ΔT") may be different — depending on the initial temperature of the cold water. And the performance of the boiler in the DHW mode directly depends on ΔT; see below for performance details.

DHW max. T

The maximum temperature of domestic hot water supplied by a dual-circuit boiler. For comparison, we note that water begins to be perceived as warm, starting from 40 °C, and in centralized hot water supply systems, the temperature of hot water is usually about 60 °C (and should not exceed 75 °C). Accordingly, even in the most modest models, this figure is about 45 °C, in the vast majority of modern boilers, it is not lower than 50 °C, and in some models, it can even exceed 90 °C.

Also when heated to a given temperature, the temperature difference ("ΔT") may be different — depending on the initial temperature of the cold water. And the performance of the boiler in the DHW mode directly depends on ΔT; see below for performance details.
Vaillant ecoTEC plus VU 15CS/1-5 often compared
Vaillant ecoTEC pure VUW 246/7-2 often compared