Knocking radiator - any advice?

[Smk80]

Hi all,

I have a rad that has suddenly started making a loud knocking noise when the heating comes on, usually last about 5mins. It's a relatively new rad, installed 4 years ago. I've tried adjusting the flow and return but this hasn't stopped the knocking.

Any idea what might be causing this and tips to sort it?

 

[terryplumb]

Does it have a TRV ? If so remove the actuator head and see if it makes a difference.

 

[Smk80]

Does it have a TRV ? If so remove the actuator head and see if it makes a difference.

No it's a rad in a kitchen extension so no TRV, just flow and return so no temperature adjustment TRV head

 

[terryplumb]

Could the knocking sound be likened to a ticking sound ? That's usually associated with heat expansion, pipes rubbing against wood flooring etc ,or the radiator brackets are missing the small plastic inserts that prevent the metal rad rubbing on the metal brackets when it expands during heating.

 

[Smk80]

Could the knocking sound be likened to a ticking sound ? That's usually associated with heat expansion, pipes rubbing against wood flooring etc ,or the radiator brackets are missing the small plastic inserts that prevent the metal rad rubbing on the metal brackets when it expands during heating.

No it literally sounds like someone is tapping the rad with a hammer about every 30secs, so it's not like the ticking on pipework (that I unfortunately have in one of our bedrooms but cannot access the pipes!)

 

[fixitflav]

No it literally sounds like someone is tapping the rad with a hammer about every 30secs, so it's not like the ticking on pipework (that I unfortunately have in one of our bedrooms but cannot access the pipes!)

Sounds to me like expansion of pipes and rad.

 

[Smk80]

Sounds to me like expansion of pipes and rad.

is that something that happens with age of the rad? Just wondering why it has only just started happening now after 4 years since being installed.

 

[terryplumb]

Something has changed,new flooring ,rad moved on its brackets( sideways) pushing pipes against flooring ,or wall if they come through the wall ?

 

[Smk80]

Something has changed,new flooring ,rad moved on its brackets( sideways) pushing pipes against flooring ,or wall if they come through the wall ?

Nope literally nothing. Been in the same place untouched since being installed (apart from a bit of dusting!)

 

[terryplumb]

Show us some pics of rad and both pipes

 

[fixitflav]

is that something that happens with age of the rad? Just wondering why it has only just started happening now after 4 years since being installed.

OK I clocked the relatively new but missed the 4 years! (which I'm not sure I'd call relatively new). No, I don't think the age of the rad would cause it, only some other change as terryplumb suggested.

 

[Smk80]

Show us some pics of rad and both pipes

thanks - attached

 

[terryplumb]

The right hand valve looks like a TRV ?
Close up pic in focus please.

 

[Smk80]

The right hand valve looks like a TRV ?
Close up pic in focus please.

here you go - hope this is clear enough.

 

[terryplumb]

The ridged collar ,on far right unscrews and the actuator head can be removed from the valve body. Show us a pic once removed of the body on the rad