Abstract: A solar heat collector comprised of modular elements which may be easily assembled and disassembled without any special tools. The system is comprised of a plurality of conduits arranged in a planar fashion for collecting solar heat and joined at their ends by interlocking connectors. The interlocking connectors are elbows and tees which have interlocking male and female flanges which may be easily connected and disconnected. Additional conduits may be added as needed and the length of the conduits may be increased by use of an interlocking coupler. The interlocking nature of the conduits, connectors and couplers allows the entire system to be constructed and disassembled. The interlocking connectors form input and output manifolds through which a heat-collecting fluid may be circulated. An adapter is provided for connecting a pipe for delivering the circulating fluid. The adapter has a neck having a predetermined inner and outer diameter for use with two standard pipe sizes.