Knocking noise from ????? and loud hum

[Angela7299]

Early early mornings because of mysterious knocking coming from bedroom radiator when heating comes on, which can also be heard in downstairs room but not so loud, could it be the bedroom rad, house 3 years old and only started after about 18 months, plumber seems to think its the pipes but why was it not there from the start then. Also when hot water in use anywhere in house a loud humming noise is heard throughout the house????

 

[GasAid]

Most "knocking" noises are due to heat expansion in the pipes; sometimes attributed to poor installation; especially if pipes have been wrapped in certain materials that break down over time; they will then rub on the joists as they expand causing an intermittent tapping or knocking sound.



What type of heating/hot water system have you got; humming noises from taps are often associated with either a faulty washer in the tap; or more commonly IMO the ball-cock in the loft; especially if the humming starts a few seconds after the tap has been opened or a few seconds after it has been closed...