Performance of a solar-assisted heat pump with an evacuated tubular collector has been analyzed both theoretically and experimentally. A domestic heating system has been designed, constructed and tested. The evacuated tubular solar collector has been used to achieve higher collector efficiencies. The effects of evaporation temperature on the heating capacity and performance of the system have been investigated. Evaporation temperature varies between 5.2 and 20.7 degrees C while storage tank temperature varies between 9 and 35 degrees C. The maximum value of the coefficient of performance of the solar assisted heat pump is obtained as 6.38 experimentally. The calculated and experimental results are seen to be in a good agreement. A cost analysis of the proposed system is made comparing with a non-solar heat pump system. (c) 2012 Elsevier B.V. All rights reserved.