Calling plumbing gurus, @Nickfromwales, @PeterW, @pocster? How do I plumb a UVC heated by a condensing oil boiler to ensure it condenses when heating DHW. I understand that with a flow temperature of say 60C and a temperature drop of 20C through the radiators it should be in condensing mode for space heating. When heating DHW the UVC coil presumably won't be able to extract enough heat to provide a 20C temperature drop so do I have to restrict the flow through the coil? If so what is the best wa