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Comparison Viessmann Vitodens 050-W Z024391 25kW 25 kW vs Viessmann Vitodens 100-W B1KF 25 kW 25 kW

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Viessmann Vitodens 050-W Z024391 25kW 25 kW
Viessmann Vitodens 100-W B1KF 25 kW 25 kW
Viessmann Vitodens 050-W Z024391 25kW 25 kWViessmann Vitodens 100-W B1KF 25 kW 25 kW
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Main
Weather-compensated automation allows you to connect an outdoor temperature sensor. Equipped with a three-way valve.
Energy sourcegasgas
Installationwallwall
Typedual-circuit (heating and DHW)dual-circuit (heating and DHW)
Heating area200 m²200 m²
Condensing
Technical specs
Heat output25 kW25 kW
Min. heat output3.2 kW3.2 kW
Power supply230 V230 V
Power consumption64 W45 W
Coolant min. T65 °С20 °С
Coolant max. T82 °С72 °С
Heating circuit max. pressure3 bar3 bar
DHW circuit max. pressure10 bar
Consumer specs
DHW min. T30 °С
DHW max. T60 °С
Performance (ΔT ~30 °C)14.5 L/min
Wi-Fi
"Summer" mode
Heated floor mode
Circulation pump
Boiler specs
Efficiency109 %109 %
Combustion chamberclosed (turbocharged)closed (turbocharged)
Flue diameter60/100 mm60/100 mm
Inlet gas pressure20 mbar20 mbar
Max. gas consumption2.48 m³/h2.8 m³/h
Expansion vessel capacity8 L8 L
Expansion vessel pressure0.75 bar1 bar
Heat exchangerstainless steelstainless steel
Connections
Mains water intake1/2"1/2"
DHW flow1/2"1/2"
Gas supply3/4"3/4"
Central heating flow3/4"3/4"
Central heating return3/4"3/4"
Safety
Safety systems
gas pressure drop
water overheating
flame loss
draft control
 
frost protection
 
water overheating
flame loss
draft control
water circulation failure
frost protection
More specs
Dimensions (HxWxD)700x400x300 mm700x400x360 mm
Weight35 kg33 kg
Added to E-Catalogseptember 2022july 2021

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 min. T

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

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.

Performance (ΔT ~30 °C)

The performance of a dual-circuit boiler in hot water mode when water is heated by approximately 30 °C above the initial temperature.

Performance is the maximum amount of hot water the unit can produce in a minute. It depends not only on the power of the heater as such, but also on how much water needs to be heated: the higher the temperature difference ΔT between cold and heated water, the more energy is required for heating and the smaller the volume of water with which the boiler can handle in this mode. Therefore, the performance of dual-circuit boilers is indicated for certain ΔT — namely 25 °C, 30 °C and/or 50 °C. And it is worth choosing according to this indicator, taking into account the initial water temperature and taking into account what kind of hot water demand there is at the installation site of the boiler (how many points of water intake, what are the temperature requirements, etc.). Recommendations on this subject can be found in special sources.

We also recall that water begins to be felt by a person as warm somewhere from 40 °C, as hot — somewhere from 50 °C and the temperature of hot water in central water supply systems (according to official standards) is at least 60 °C. Thus, for the boiler to operate in the mode ΔT ~ 30 °C and give out at least warm water at 40 °C, the initial temperature of cold water should be about 10 °C (10 + 30=40 °C). A similar temperature can be found in wells in the warm season, and cold water in the ce...ntralized water supply system often warms up to 10 °C in the warm season. However, boilers, including dual-circuit boilers, are switched on mainly in cold weather, when the initial water temperature is noticeably lower. Accordingly, if the boiler is used as the main water heater, heating to the claimed temperatures (see "DHW min. T", "DHW max. T") often requires a greater ΔT than 30 °C, and the performance is less than indicated in this paragraph. But when operating in the preheating mode (when the water is heated to the desired temperature by an additional device like a boiler), this parameter describes the capabilities of the unit very reliably.

Wi-Fi

The boiler has a Wi-Fi module. This function is often used to remotely control the unit from a smartphone, tablet or other device. The specific features of such control may be different: for some models, you need to install a special application, for others, control is available through a page in any browser; the gadget can be connected directly or via the Internet, etc. The details of using Wi-Fi in each case should be clarified separately. Note that through such a communication channel, you can not only control the unit but also receive notifications from it — about the operating mode and parameters, about the current state, about failures and malfunctions, etc. At the same time, this function is relatively rare. In most cases, traditional control is sufficient.

Heated floor mode

The boiler has a special mode for underfloor heating systems.

Underfloor heating differs from conventional heating systems primarily by a lower coolant temperature — otherwise the floor could be too hot for comfortable use (plus, high temperatures are also undesirable for flooring and furniture installed on it). In addition, boilers with this function are distinguished by increased pump power. In order to ensure efficient circulation of the coolant through branched heating circuits that have rather high resistance.
Viessmann Vitodens 050-W Z024391 25kW often compared