Hi guys, well I have at last completed our solar system including the 2nd hand Riomay tubes I got from James on the forum (can’t believe that was a year ago), see pic. As we have a 250l DHW and 1000l UFH TS, I am wondering the best way to configure it.

During the summer I have just been heating DHW before it swaps over to TS as a heat dump really but now heating switched on I need to decide what to heat first and to what temperature. The gas boiler tops up both tanks to required temperature when required. The UFH heating only needs 40 degrees so in terms of energy use, is it better to heat the TS with the freely available lower grade heat first or try and get the DHW tank up to temp but that means solar is waiting to pump longer trying to reach the higher DHW temp or does it make no difference as energy is energy whether it’s the solar or gas and whether its low or higher temps?

The TS is a solar specific model with an external solar loading coil. We also have PV feeding into immersions at the top & bottom of DHW and bottom of TS in that order of priority. We have 90 Nav tubes as well as the Riomay so we are aiming to assist heating where possible, the TS is the buffer for the UFH to minimize boiler use where possible, we will also have a wood burner connected to heat both tanks in the future.