Bosch BASIC 22/25 2300 CT 200

Product detailed description

Frequently Asked Questions

• How exactly do I choose the output of a BOSCH condensing boiler? The starting point is the calculated heat loss of the heated building (most reliably taken from the project documentation or an energy certificate). If you don't have a project, you can roughly estimate about 60-100 W per m² of floor area for a commonly insulated house built after 2000, or 100-150 W/m² for an older, uninsulated house - the exact figure varies depending on the number of floors, ceiling height, the number and quality of windows, and the building's orientation. A boiler oversized for its output switches on and off more often (so-called cycling), which shortens its service life and reduces efficiency; an undersized boiler, on the other hand, cannot heat the house sufficiently on frosty days.
• Why is a condensing boiler more economical than a conventional one? A condensing boiler additionally uses the heat hidden in the water vapour produced when gas is burned - in a conventional boiler this heat escapes unused through the flue, while in a condensing unit it is cooled below the so-called dew point, the vapour condenses, and the released heat is returned to the heating circuit. Thanks to this, condensing boilers achieve an efficiency of approximately 105-110% relative to the calorific value of the gas, compared to the usual 85-92% for conventional boilers.
• What type of flue does this boiler need? Most modern condensing boilers are so-called “turbo” units (with a sealed combustion chamber) and require a concentric (coaxial) or separate flue gas outlet and combustion air intake routed through an outer wall or the roof - so a functioning chimney is not needed. The exact type and maximum length of the flue (depending on the 60/100 or 80/125 mm diameter) can be found in the technical documentation for the specific model, or you can consult our customer service.
• What does the ErP energy class stated for the boiler mean? This is a mandatory efficiency label for heating appliances under the EU ErP (Ecodesign) directive, similar to the energy labels used for refrigerators. Condensing boilers commonly achieve class A, or even higher in combination with room controls (e.g. A+ when using weather-compensated control and a room thermostat).
• Can I install and connect this boiler myself? No. Connection to the natural gas supply, the electrical network, and the flue is by law reserved exclusively for a person with the appropriate qualification (usually an authorised service technician for the given brand or a certified gas appliance inspector). After installation, the boiler must be commissioned by the manufacturer's authorised service, which is usually also a condition for the warranty to be valid.
• What about servicing and the warranty? Most manufacturers require a regular annual service inspection by an authorised service provider in order for the warranty to remain valid even after its standard expiry (an extended warranty subject to regular servicing is common especially with the brands Vaillant, Protherm, and Viessmann). The exact warranty terms can be found in the warranty certificate supplied with the boiler.
• What is included in the delivery of this specific product? The exact package contents (the boiler itself, possibly a hot water tank, room controls, and other accessories in the case of a set) are stated in the product name and in its technical parameters above on this page.