11 abril, 2019 Off By admin

A solar water heater is mainly suitable for heating sanitary water. However, many people wonder if you can also heat the house. In this article we will see if we can have HEATING WITH SOLAR WATER HEATER.


The answer to this question is: yes, you can, but not without the help of another source of heat, such as a central heating boiler or a heat pump. Find out more about this in this article.

Heat a house with a solar water heater: beginning


In the summer, the sun provides the greatest amount of energy and can heat almost all the sanitary water with the free energy of the sun. 

In the other seasons, the solar water heater will often depend on the subsequent heating to keep the water temperature high enough. 

Throughout the year, on average you will achieve an energy saving of 50 to 65% (sanitary water heating). In colder seasons, a solar water heater runs much less than in the summer. 

And it is precisely in these periods that it needs heating. Therefore, a solar boiler can never completely replace a central heating boiler or a diesel boiler. 

It can cover a maximum of 15 to 25% of the total energy consumption (sanitary and central heating). 

A solar water heater can serve as an additional source of energy and help preheat the central heating water.

Possibilities for a solar water heater.

It is possible to heat the entire house with a solar water heater, as long as it is combined with a central heating boiler or a heat pump. Discover below the possibilities for heating completely 

  1. Heat the house with a combined solar water heater

If you want to heat the house with a solar water heater, you can opt for a combined solar water heater. This is a solar water heater system in which boiler and central heating are combined. With a system of this type, it can heat both the central heating water and the sanitary water. 

This system is not cheap and, in fact, it is only interesting if you want to install a high efficiency (new) boiler in combination with underfloor heating or wall heating.



Another possibility is to make a combination of an existing central heating boiler and a solar water heater (central solar water heater). This is usually the most appropriate option. 

The storage tank in the system has two separate heat coils, so that not only the domestic water is heated, but also the central heating water. The following also applies to this system: it is only useful in combination with floor or wall heating.

2) Heating of the house with solar water heater and heat pump.

You can also combine a solar water heater with a heat pump to heat the house. You need a large storage tank to which both systems are connected. This system is particularly suitable for very low temperature heating (ZLTV) with wall or floor heating.


Return and performance

On average, you can save 15 to 25% on heating costs with a solar water heater. 

The return obtained for heating the home is less than the return for heating the domestic water (50-65%) because precisely in cold periods, when you want to heat, the sun shines with less intensity.

 Keep in mind that you need a larger buffer volume and a larger collector surface that you want to use solar heat effectively to heat the house.

When is solar heating useful?

With traditional heating with standard radiators, it is not really useful to heat the house with the help of solar collectors. 

The water temperature of the central heating is so high (60 to 70 degrees Celsius) that the subsequent heating must be turned on too frequently. 

As a result, the return is quite low and installation costs are barely recovered. With low temperature heating (floor or wall heating), the situation is different and the use of solar collectors can be useful. 

The temperature of the central heating water is then considerably lower (15-40 degrees), which makes it easier for the solar boiler to preheat the central heating water.

Read more Types of solar collectors