The research is focused on energy sorrel as a fuel for local low-power heating systems with output up to 100 kW. Sorrel is perennial plant surviving in its location nearly 18 years which is very good from the point of crop expenses. It is a robust plant with height of about 2 m in second year of plantation. Dry phytomass is energetically rich fuel with total heating value 17.5 – 18.0 MJ*kg-1 at the average yield of 10 tons per hectare. An experimental combustion of pure sorrel and its blends were done with boiler VERNER A25 – a hot water boiler for pellets. 11 different sorrel fuels consisting of 5 primary kinds were tested during the experiment: sorrel (Rumex tianshanicus x Rumex patientia), Phalaroides arundinacea, Canabis sativa, pine-bark, sorrel (Rumex tianshanicus x Rumex patientia), brown coal. Based on collected data it is possible to obtain an overview of these fuels and their emission properties. Satisfactory values of CO concentration are possible to gain partly by choosing appropriate combustion device and its settings and partly by mixing with other types of fuel. In the case of sorrel the combination of both has been shown very useful. It is very hard to ...