District heat supply to residences is effective for the use of woody biomass for local production for local consumption. Therefore, we conducted a survey on the actual conditions and factors affecting supply efficiency. The average supply efficiency was 69.7%. In the investigation of factors influencing supply efficiency, it was confirmed that the effect of the amount of heat received was the largest, with a partial correlation coefficient of 0.64. When the effect of heat quantity received was excluded, the partial correlation coefficient of supply temperature was -0.31, indicating that supply efficiency tends to be higher at lower supply temperatures.