OK. Boiler comes on and for the first 10 seconds or so, it sounds like someone is smacking the pipes with a hammer, then it runs quietly for a bit, then might start again.. British Gas came round (we have the 3star cover thingy) a few weeks back and swapped the pump, which seemed to make it go away, but now it's back again. The guy said if it comes back, we would need to have the system 'power flushed'. I think he was just looking for commission on an overpriced unnecessary job. The water runs clear when I bleed the rads and we have a MagnaClean thingy installed to keep the water clean. I haven't cleaned the filiter thingy in the MagnaClean, so guess that might need doing, but why the banging noises?
So, STW hive mind, what to check next?
