USA
Catalog   /   Climate, Heating, Water Heating   /   Heating & Boilers   /   Boilers

Comparison Italtherm CITY CLASS 25 F 24 kW vs Vaillant ecoTEC pure VUW 286/7-2 24 kW

Add to comparison
Italtherm CITY CLASS 25 F 24 kW
Vaillant ecoTEC pure VUW 286/7-2 24 kW
Italtherm CITY CLASS 25 F 24 kWVaillant ecoTEC pure VUW 286/7-2 24 kW
Outdated ProductOutdated Product
TOP sellers
Energy sourcegasgas
Installationwallwall
Typedual-circuit (heating and DHW)dual-circuit (heating and DHW)
Heating area192 m²192 m²
Condensing
Technical specs
Heat output24 kW24 kW
Min. heat output8.5 kW7.6 kW
Power supply230 V230 V
Power consumption103 W110 W
Coolant min. T35 °С30 °С
Coolant max. T80 °С80 °С
Heating circuit max. pressure3 bar3 bar
DHW circuit max. pressure6 bar10 bar
Consumer specs
DHW min. T35 °С35 °С
DHW max. T55 °С60 °С
Performance (ΔT=25°C)13.7 L/min
Performance (ΔT ~30 °C)11.6 L/min
"Summer" mode
Heated floor mode
Warm start
Circulation pump
Boiler specs
Efficiency93.3 %105.4 %
Combustion chamberclosed (turbocharged)closed (turbocharged)
Flue diameter
60/100 mm /80/80 for split flue/
60/100 mm
Inlet gas pressure20 mbar20 mbar
Max. gas consumption2.72 m³/h3 m³/h
Expansion vessel capacity8 L
Expansion vessel pressure1 bar
Heat exchangerstainless steel
Connections
Mains water intake1/2"3/4"
DHW flow1/2"3/4"
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)727x400x300 mm720x440x372 mm
Weight30 kg33.5 kg
Added to E-Catalogaugust 2017june 2017

Condensing

Boilers generate additional heat by condensing water vapour from combustion products. In such units, the combustion gases, before entering the flue, are passed through an additional heat exchanger, in which they are cooled, and the water vapour condenses and transfers thermal energy to the coolant. It allows you to increase the efficiency by 10 – 15% compared to boilers of the classical design — up to the fact that in many similar models, the efficiency exceeds 100% (for more details, see "Efficiency").

The condensation principle of operation is most often found in gas models (see "Power source"); however, solid and liquid fuel boilers with this feature are also produced.

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 min. T

The minimum 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 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=25°C)

The performance of a dual-circuit boiler in the DHW supply mode when the water is heated by 25 °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 options ΔT — namely 25 °C, 30 °C and/or 50 °C. And it’s 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 ΔT=25 °C mode and produce at least warm water at 40 °C, the initial temperature of cold water must be at least 15 °C (15+25=40 °C). It is a rather high value — for example, in a centralized water supply system, cold water...reaches 15 °C, except in summer, when the water pipes warm up noticeably; the same applies to water supplied from wells. So this performance is a very conditional value. The boiler does not work so often with a temperature difference of 25 °C. Nevertheless, the data for ΔT=25°C is still often given in the specifications — including for advertising purposes since it is in this mode that the performance figures are the highest. In addition, this information may be useful if the boiler is used as a pre-heater, and heating to operating temperature is provided by another device, such as an electric boiler or instantaneous water heater.

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.

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.
Italtherm CITY CLASS 25 F often compared
Vaillant ecoTEC pure VUW 286/7-2 often compared