Have a Potterton Nrtaheat MK2F 10-16 with a pumped CH and gravity HW by indirect heating via cylinder. recently had bathroon brassware replaced and ensuite replaced with new shower unit and sink. At this time rads in both locations were replaced by heated towel rails. before all this occured everything was fine.
All radds and towl rails are fine, but no HW. there is no circulation throigh cylinder. No air in system for sure, cylinder feed gets hot bu cylinder return to boiler does not warm up. feed and return pipes cut, circulation pump fitted to clean return - boiler-feed loop and also cylinder ip to cylinder op. . feed vent is clear and well clear of water level in the overflow tank in loft. What can it be?? maybe the cylinder coil is blocked too much for gravity feed to circulate? Cleaning agent was added to HW and left for 3 days before we tried the circulation pump.
Any ideas??
All radds and towl rails are fine, but no HW. there is no circulation throigh cylinder. No air in system for sure, cylinder feed gets hot bu cylinder return to boiler does not warm up. feed and return pipes cut, circulation pump fitted to clean return - boiler-feed loop and also cylinder ip to cylinder op. . feed vent is clear and well clear of water level in the overflow tank in loft. What can it be?? maybe the cylinder coil is blocked too much for gravity feed to circulate? Cleaning agent was added to HW and left for 3 days before we tried the circulation pump.
Any ideas??