A heat buffer is a tank connected to the heating system, whose task is to increase the water capacity of the installation and store it for later use. The buffer connected to the central heating system, after heating, discharges the water heat to heat receivers, such as radiators or underfloor heating.

The boiler, working in a system with a heat buffer, heats the buffer to high temperatures, around 80-90°C. Due to the larger amount of water in the system, it takes more time than when the system operates without a buffer, but it allows for the accumulation of a large amount of the agent, immediately ready for long-term distribution in the heating circuit.

After heating the buffer to the set temperature, the boiler stops working and resumes operation when the temperature in the buffer tank drops, i.e. the accumulated thermal energy is used up.

Since the agent in the buffer is stored in a layered system, there is no need to wait until the buffer is fully heated to start the installation.

The shape of the heat buffer resembles a larger vertical hot water tank.