Hammering noise

[cass]

Hi was wondering if someone could help.New to forum and have just started svq L2 so have only covered health and safty etc. The thing is my central heating system is making a hammering nois after about 5 hours of being turned on ,cant sleep at night so having to turn off.Can someone tell me do i need to bleed radiators,or is this the symtoms of somthing else.

 

[john phillipson]

Hi check your circulation pump, if its stalling you will get a hammering noise. John phillipson

 

[stevetheplumber]

sounds more like a trv on backwards