continuous banging in pipes although heating system not on

[concalmum]

Hiya, first post so please be gentle.
I have a Vokera 12-48 R.S.E. Mynute (thats what says on casing) Gas, flued to the outside with seperate timer and room thermastats, all rads (9 in total) have trvs fitted except one in the hall. Heating and hot water timed to come on at 6.30 go off at 7.30am all working fine. Problem was that at about 10.30 almighty banging noises coming from cupboard where boiler, hot water tank and pipes etc are. Noises seemed to be in pipes and travelling through house, could even hear it outside. Was continuous and rythmic like on a spin cycle, in fact actually thought next door had washing machine on and the vibrations were coming through into my house but not that as she not in. then after about 5 minutes it has stopped. Does anyone have any ideas what could have caused this. Have BGas 3 star cover but no point calling out when it prob won't make noise on demand. Nothing has been changed or done to the system or the house or other plumbing. I know this prob sounds trivial but don't want it happening in middle of night if can be helped have baby and get very little sleep as it is. When heating is on I get the usual ticking, creaking noises pipes and whoosing noises so could it simply be there is too much air in system and the radiators just need bled.
Any help from anyone would be greatly appreciated.

 

[kevplumb]

methinks TRV wrong way

 

[ChrisR]

Have had this twice - banging when the heating's all supposed to be off. Both times it seems like the boiler was coming on for some reason, when there was no valve open, so the boiler boiled.

Once it was cleared by changing the microswitches in all the 2 port valves on an S plan system with several zones. It was a fiddle, but cheaper than changing all the heads. Obviously any one of them could have been faulty. Once you've done the first couple you get quicker at it! You have to snip the spade connectors like little toe nails so you can solder the wires back and leave enough room.

Another instance was on a system with 100% trv's. The flow switch in the boiler (Baxi 100/Promax type) should have held the boiler off, but it was stuck open. During the day there was some UFH on which provided enough of a bypass, but last thing at night it went off...
There was a query on that one about the programmer doing odd things - a Horstmann 3 zone one.

 

[werewolf]

Phone BG you`ve paid your money get your money`s worth.