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Buderus Frequently Asked Questions


Read our Frequently Asked Questions about Buderus and Buderus product line.

Solar Frequently Asked Questions

How does a solar thermal hot water system work?

  • A Buderus solar thermal system for domestic hot water consists of a number of components; a solar collector, a pump station, a solar controller and an indirect hot water storage tank. The solar collector, located on the roof, collects the sun’s energy and transfers the heat to the storage tank via the tanks internal heat exchanger. The storage tank allows the hot water to be stored until it is used. The controller activates the system's pump only when there is enough solar energy to create hot water. An existing Buderus wall-hung or floor- standing boiler can also be integrated into the solar system providing back-up for domestic hot water. The solar system can also complement the boiler for space heating by reducing the number of boiler starts, thus saving costly fuel.

What is the life expectancy of a solar hot water system?

  • The typical life expectancy of a Buderus solar hot water system is 20-30 years. If the system is properly maintained, it can last over 30 years. Buderus has installed many systems for over 25 years. Many of these systems are still reliably producing solar hot water.

How much greenhouse gas can be offset by a solar hot water system?

  • A typical residential solar water heater will offset greenhouse gas emissions by about 1,600 pounds of carbon dioxide (CO2) per year. That’s equal to the amount of CO2 released by an average vehicle every 1,700 miles.

Are there any financial incentives for solar hot water systems?

  • Yes, the American Recovery and Reinvestment Act of 2009 made significant changes in tax credits for energy efficient improvements for both residential and commercial installations, including solar systems. In addition, there may be local government or utility incentives where you live. There is a great amount of information on the new tax credit law at

How much maintenance does a solar hot water system require?

  • A properly designed Buderus solar hot water system requires very little maintenance. The heat transfer fluid should be checked once per year and is typically replaced every 5 years. The pipe insulation and controller settings should also be checked as part of the annual system check-up.

How many years experience does Buderus have in solar water heating?

  • Buderus has been manufacturing and designing solar water systems for over 25 years. Buderus is part of the Bosch Group and has manufacturing plants in Germany and Portugal. Buderus solar is one of the largest and most reputable manufacturers in the world. Since 1995 Buderus has shipped over 4 million ft2 of solar thermal collectors. Buderus continues to invest in research and development and manufacturing capacity to bring innovative and high quality solar products to market.

What is the difference between a flat plate and evacuated tube collector?

  • Flat plate collectors are the most common solar thermal collectors available for residential and commercial applications. They are thermally insulated and robust, covered with a sheet of high tempered low-iron glass. The plate absorber transfers the heat to a network of small pipes under the absorber which contain a heat transfer fluid. They typically have a low profile and integrate into the roof line creating an aesthetically pleasing appearance. Flat plate collectors are ideally suited for medium temperature applications such as domestic hot water and space heating.
  • An evacuated-tube collector contains several individual glass tubes, each containing an absorber plate bonded to a heat pipe and suspended in a vacuum. The pipe transfers the heat to a condenser through the top of the tube. The condensers are attached to heat exchangers in a well-insulated manifold. The evacuated tube collectors generate high temperatures making them ideal for commercial and industrial process heat applications.

Will a solar hot water system work on a cloudy day?

  • Yes, even when you have a cloudy day, diffuse light penetrates the cloud layer and heats up the solar collectors. The effectiveness of the collector depends on the construction. The Buderus SKS4.0 flat plate collectors are hermetically sealed and filled with an inert gas. This creates a thermal blanket increasing heat retention. The SKS4.0 also begins to work earlier and heat-up faster even in low light condition due to a highly selective absorber coating that maximizes heat absorption from the sun.

How long does it take to install a solar hot water system?

  • A typical Buderus residential solar hot water system using 2- 4 collectors takes about 1-2 days to install depending on the location and roof type. Larger commercial systems may take longer because of the scale, equipment and labor required.
More on financial incentives
SEIA Guide to Federal Tax Incentives
State Incentives
State-by-State Incentives for Solar Water Heating (Word Doc)