whooshing when valve opens

[Bedsman]

When the hot water or central heating system is switched on and the valve in the airing cupboard opens there is a whooshing noise . Eventually the noise goes away and it all seems to be working until I start to get some banging noises from the boiler. At this point I have to switch the boiler off and switch it on again which then results in a sudden rush of water into the boiler. It all then starts working properly. It cant be air in the system cos I have an automatic air vent in the airing cupboard. I also have an air separator. The boiler has been serviced and the system descaled Any ideas?? My boiler is an Ideal Classic

 

[JBPHS]

There could be a partial blockage. This usually occurs around the air separator. Can sometimes be diagnosed by running a magnet around the pipework and air separator. If it sticks, there is a presence of magnetite. If it doesn't stick, could still be some blockage. Personally I don't bother rafting about like this. I just normally isolate and partially drain the system, cut out pipework, replace or clean and refit. Word of warning the magnetite is a pig to clean off anything it comes into contact with.

James.

 

[Bedsman]

The air separator is new so there shouldn't be a problem with that, but I will try the magnet idea. How do I check if the automatic air vent is turned on properly or do they just work without being turned on and off?

 

[jeff the gasman]

You either have
1 faulty boiler thermostat.
2 blocked system.
If you don't understand that, you need a decent plumber to sort it.
Jeff