In December my 40 year old oil boiler was replaced with a Saunier Duval Thema Condens gas boiler. All was well for a while and then the hot water side stopped working. A blocked plate heat exchanger was diagnosed and replaced. A power flush was also carried out and a Spirovent filter fitted in the return line. Again it was ok for a few weeks until the same problem occurred. Checking the filter revealed it to be clean, but the heat exchanger was again blocked with the same black, carbon like substance. The same problem has occurred on a number of other occasions, and as a last resort, a Magnaclean filter has also been fitted.
My plumber is reluctant to do a more aggressive powerflush as we don't know the condition of the underfloor pipes, and we can't understand why the filters fail to pick up the crud. Any ideas anyone?
My plumber is reluctant to do a more aggressive powerflush as we don't know the condition of the underfloor pipes, and we can't understand why the filters fail to pick up the crud. Any ideas anyone?
