Protherm MiSet

Product detailed description

Frequently Asked Questions

• How exactly do I choose the right output for a PROTHERM condensing boiler? The starting point is the calculated heat loss of the building being heated (most reliably taken from project documentation or an energy certificate). If you don't have a project, you can roughly estimate around 60-100 W per m² of floor area for a typically 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. An oversized boiler switches on and off more often (so-called cycling), which shortens its lifespan and reduces efficiency; an undersized boiler, on the other hand, cannot adequately heat the house on freezing days.
• Why is a condensing boiler more economical than a conventional one? A condensing boiler also makes use of the heat hidden in the water vapour produced when gas is burned - in a conventional boiler this escapes unused through the flue, while in a condensing boiler 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 around 105-110% relative to the calorific value of the gas, compared to the usual 85-92% for conventional boilers.
• What type of flue gas extraction does this boiler need? Most modern condensing boilers are so-called turbo boilers (with a sealed combustion chamber) and require a coaxial (concentric) or separate flue gas extraction and combustion air intake routed through an external wall or roof - so a functioning chimney is not needed. The exact type and maximum length of the extraction (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 shown 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 when combined 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 gas extraction must, by law, be carried out exclusively by a person with the relevant qualification (most often an authorised service technician of 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 to keep the warranty valid even after its standard expiry (an extended warranty with regular servicing is common especially for brands such as 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 contents of the package (the boiler itself, possibly a hot water cylinder, 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.