Draining radiator?

[ben100]

I’ve got this radiator that I need to drain down & remove to clean out due to sludge. Can I drain it with that drain valve on the left because as you can see that it connects to the radiator but that pipe also runs along past the radiator on the right?

 

[ShaunCorbs]

That will drain the whole central heating system as well

 

[ben100]

That will drain the whole central heating system as well

So the lockshield valve on the left was boiling hot but I noticed the thermostatic valve on the right was cold, is this normal? Both valves I had to unscrew the screw to take the plastic caps off & they both had the lockshield type turn.

 

[ShaunCorbs]

So the lockshield valve on the left was boiling hot but I noticed the thermostatic valve on the right was cold, is this normal? Both valves I had to unscrew the screw to take the plastic caps off & they both had the lockshield type turn.

That’s because it is a lockshield valve you tried opening the cooler one by 1/4 of a turn ?

 

[ben100]

That’s because it is a lockshield valve you tried opening the cooler one by 1/4 of a turn ?

Sorry what do you mean it is a lockshield valve? I know that normally one side is a lockshield & the other is a thermostatic but on this radiator when I took both plastic caps off they both had lockshield type spindles on both sides, only difference was the caps. As for opening the cooler one I did open it more but it stayed the same. I’ve had a check on my own radiator valves in my home & I also have a couple of radiators where the lockshield side valve is cold compared to the boiling hot thermostatic valves on the other side, so I was wondering if this was normal & supposed to be like that or a fault?

 

[ShaunCorbs]

Sorry what do you mean it is a lockshield valve? I know that normally one side is a lockshield & the other is a thermostatic but on this radiator when I took both plastic caps off they both had lockshield type spindles on both sides, only difference was the caps. As for opening the cooler one I did open it more but it stayed the same. I’ve had a check on my own radiator valves in my home & I also have a couple of radiators where the lockshield side valve is cold compared to the boiling hot thermostatic valves on the other side, so I was wondering if this was normal & supposed to be like that or a fault?

You don’t have a trv on that rad just two individual lockshield valve

 

[ben100]

You don’t have a trv on that rad just two individual lockshield valve

Ah ok I’ve never come across ones with two lockshields before but these are old radiators so it makes sense. As for one valve being cold compared to the other being boiling hot, is that normal or is something wrong?

 

[ShaunCorbs]

Ah ok I’ve never come across ones with two lockshields before but these are old radiators so it makes sense. As for one valve being cold compared to the other being boiling hot, is that normal or is something wrong?

Normal flow is the hot one colder one is the return

 

[ben100]

Normal flow is the hot one colder one is the return

Ok so when I'm draining a radiator like this down normally you would count how many turns it takes until shut off on the lockshield valve side for balancing. Which side do I count the number of turns on this as they are both lockshield valves?

 

[ShaunCorbs]

Cold side and normally 1/4 of a turn open

 

[ben100]

Cold side and normally 1/4 of a turn open

Last question, would it be normal for it to be more than that as when I turned the cold side it was open a lot more than 1/4?

 

[ShaunCorbs]

Depends if it was balanced I’ve had older rads fully open both sides