I recently hired a flusher from HSS - they come with really easy to follow instructions and HSS can supply all the chemicals and any extra bits that you need. I was amazed at how easy it was to do - and it cost me less than £100
Recently replaced pump, valve and programmer on my HW/CH system (also moved a couple of radiators). Flushed and refilled. Radiators all seem OK but the HW heating coil in the cylinder sounds like it is full of bubbles and I have to bleed it daily and bleed the pump twice a week. This has been...