"Hi there. Been a while since I bought system, I am almost there!  Fitted roof mounts to the same pitch as the garage roof along side summer house.  Had some problems with leaks!  Lost almost a gallon of solar fluid oops!  Am now running main hot water pipe under ground to feed a combi boiler via non return valve and thermostatic mixer valve to main house.  Have reached temperatures of 65-70c.  At this stage I need to fit a radiator in summer house as temperatures keep rising.  On the whole I am well pleased with system, if I can do it, anyone can!  Tank used is Ariston 210 litre indirect unvented cylinder."

Note that Steven's underground pipe is covered in insulation, then the whole lot fitted inside plastic drain pipe, then buried in sand.  Ensure your combi boiler is suitable for use with pre-heated water when installing a system like this.