In countries like Latvia, with large forest areas and intensive forestry, large quantities of forest residues are formed. The primary use of forest residues is processing it into forest woodchip fuels. However, it is generally thought that forest woodchips are of poor quality, with one of the main weak spots being low ash melting temperature that accounts for the creation of molten ash in boilers. Molten ash formation in boiler stoves significantly increases the equipment maintenance costs. Thus, this resource is not used to its full potential. The ash melting temperature varies for different materials. The different ash melting properties of different logging residue fuel parts is investigated, highlighting the fractions which contribute to the formation of molten ash in the largest extent. Ash melting properties are evaluated separately for pine and spruce branches and needles. The ash melting properties are evaluated in a mutual relationship as well as in the context of previous research.