rad hot at top but not bottom (myson thermostat on rad)

[joebells]

Hi,
total noobie to this forum and to DIY in general (and plumbing!).
Have just moved into my 1st house and in at the deep end!

One of the rads is only heating up at the top, and even then not getting very hot. I've bled all the rads in the flat following advice found on this forum.

The offending radiator has got a fancy Myson thermostat looking thing on it (I'm guessing that's what it is - only one other rad in the flat has this device on it)

I read on another thread that it could be "sludged up"..
But could it be something to do with the Myson thingy??

I have no idea how to proceed really, all I do know is I have no money for a plumber right now!! If anyone could give some advice that'd be great.
Cheers,
Joe

 

[gas4you]

Try removing the myson head only part of the valve and gently tapping the pin in the middle until it pops up freely after being pushed down.

If this fails then it does sound as though there is sludge in the radiator.

You would need to turn both valves off to this rad then drain it, remove it and take outside and flush through with a hose connected to the cold mains.

 

[Balenza]

Could be sludge alright.
I'd release the nut on one end of the rad and see what colour the water comes out.
If its black then thats not a good sign.

 

[joebells]

Thanks for the advice gas4u and balenza.

balenza i don't understand what nut you mean?

gas4you
This is like the thermostat (but mine's a bit less moders looking)

where would i remove it from??

sorry for my ignorance

Joe

 

[gas4you]

The large Knurled nut at the bottom of the plastic head.

Not either of the nuts on the rad tail or the pipework

 

[joebells]

Thanks G4u,
just to confirm,
I don't need to drain the rad or turn my central heating off or anything special do I??? I just screw that sucker right off??

Thanks for the quick response...appreciated

 

[Balenza]

Joebells wrote

balenza i don't understand what nut you mean?

The one to the pointing right horizontally in your pic with the rad turned off and the air bleeder opened.
You unscrew the head by undoing the chrome retainer below the white plastic head.

 

[joebells]

Joebells wrote

balenza i don't understand what nut you mean?

The one to the pointing right horizontally in your pic with the rad turned off and the air bleeder opened.
You unscrew the head by undoing the chrome retainer below the white plastic head.

sorry balenza
when you say "rad turned off" what do you mean? valves closed? boiler off? or just central heating off? or something else?

as i said i'm very new at this. Thanks for the help

 

[gas4you]

Thanks G4u,
just to confirm,
I don't need to drain the rad or turn my central heating off or anything special do I??? I just screw that sucker right off??

Thanks for the quick response...appreciated

No just take the head off.

 

[Balenza]

The center pin only pushes the inner stem downwards like a micro pushrod inside a slide.
An internal spring pushes the inner stem back up and if siezed then may need removing, cleaning ,light oiling and replacing.

Here is what the internal components look like though your valve being older may be slightly different -