Device characteristics ATV temperature valve, installed on the return part to the boiler, protects the boiler for solid fuel against corrosion caused by too low temperature of water returning to the heat source. Maintenance of the return temperature at fixed level specified by the boiler manufacturer allows to protect it from moisture condensation on the water lining, as well as negative processes of contamination of the furnace by tars and soot. Relatively high return temperature prolongs the life of the boiler and increases its efficiency. ATV temperature valves can also work as insolation valves. ATV temperature valves should be installed in each system equipped with the heat buffer (accumulation tank) and are recommended for each boiler for solid fuel. ATV temperature valves are made of brass and have internal threads. The valve contains the thermostatic element, which adjusts the temperature of water returning to the boiler and maintains it at the constant minimum level. The rated temperature of the valve is determined by the opening temperature, at which the opening of the terminal A begins through the thermostatic element. The installation position of ATV valves can be chosen freely. The application of ATV valves does not require the use of any additional control valves on the terminals. The design of ATV temperature valves enables the exchange of the thermostatic element, without the need to remove the valve from the system.