Potential for family size biogas plants is estimated to be about 12 lakh in Gujarat. Nearly 2 lakh units have been actually installed by 1993. Deenbandhu model appears to be the most popular. In this paper we present an estimate of the reliability of denbandhu plants. We also present an analysis of the manner of use. Deenbandhu model is found to be quite robust. But the manner in which most people use the plant, it is unlikely to give them the full benefit. This needs rectification.