Just wanted to give an update and a HUGE thanks to everyone for all your help - @Nige F , @dilalio, @MeldrewsMate , @MrBenchmark , @terryplumb. It was indeed a blockage at the high level return pipe on the hot water cylinder. There's a 22mm/22mm/15mm compression tee, with the 15mm side at the top connected to the feed pipe from the header tank - is that what you were referring to as an "inverted tee" @MrBenchmark?
Starting by trying to rod down from the header tank but got resistance just before the tee, so disconnected the tee. Drilled out the blockage in the 15mm pipe and the tee. Reconnected and system filled first time. So, added some cleanser, will run for a few days and then flush it out.
What are people's thoughts on these magnetic filters - worth installing, or just flush out every few years?
Starting by trying to rod down from the header tank but got resistance just before the tee, so disconnected the tee. Drilled out the blockage in the 15mm pipe and the tee. Reconnected and system filled first time. So, added some cleanser, will run for a few days and then flush it out.
What are people's thoughts on these magnetic filters - worth installing, or just flush out every few years?
