How much water in a radiator?

[mike004]

Draining a 70 cm x 70 cm single panel radiator prior to removing it. How much water should come out of it? I gave up after nearly 10 litres, fearing I was draining the whole central heating system.

The temperature control valve -- I screwed this clockwise as far as it would go. Is this enough to turn off supply to the rad, or do I need to fit a special cap? I later unscrewed the top section of this and confirmed that the mechanism was working OK. Screwing clockwise would depress the brass nipple. It's not a thermostatic valve, just a manual 1 to 5 dial control.

Lockshield valve --I used an adjustable wrench to turn the central brass spindle a quarter-turn clockwise. That's as far as it would go. I was expecting to have to turn it much more. Is that enough to turn off the rad supply?

Thanks
Mike

 

[ollski]

I would say you have a valve passing although I can't really picture the control valve you have.

 

[nickso]

700 by 700 probably only has a buckets worth of water in it.

as ollski says one of the valve is passing.

 

[gas4you]

1 bucket = about 5 gallons = about 22 litres

 

[ollski]

5 gallons?, that's a hell of a bucket I thought 3 was standard. tend to drain rads by a clover butter container but by 10 litres you would be down to a trickle at the end.

 

[scatmanjohn]

Open the bleed nipple.

Is water coming out of it?

If yes you have a passing valve.

If not drain a bit more

 

[gas4you]

5 gallons?, that's a hell of a bucket I thought 3 was standard. tend to drain rads by a clover butter container but by 10 litres you would be down to a trickle at the end.

No wonder I've always thought I was well endowed then

 

[mike004]

>Open the bleed nipple.
Is water coming out of it?
If yes you have a passing valve.<

Yes, water is still coming out of the bleed nipple.
So, one of the valves is not fully closed.
Would this be the lockshield valve, which only took 1/4 turn to close.
Or the thermostatic control valve -- maybe I need to fit a special cap?

Thanks
Mike

 

[oldhenry]

what about turning valves on and off a few times to get them in the mood to turn right down?
my TRV jam if not twiddled occasionally, take the top bit off and see if the pin moves in and out, if not hit it.
ps I am not responsible if you ruin it, I am a pure amateur who uses common sense, or not, if that works better.

 

[JohnD]

I hope you've tied up the ball valve or turned off the supply to the F&E

otherwise you will be trying to drain the water mains.

 

[EliteHeat]

what about turning valves on and off a few times to get them in the mood to turn right down?
my TRV jam if not twiddled occasionally, take the top bit off and see if the pin moves in and out, if not hit it.
ps I am not responsible if you ruin it, I am a pure amateur who uses common sense, or not, if that works better.

I like your style

 

[mike004]

what about turning valves on and off a few times to get them in the mood to turn right down?
my TRV jam if not twiddled occasionally, take the top bit off and see if the pin moves in and out, if not hit it.
ps I am not responsible if you ruin it, I am a pure amateur who uses common sense, or not, if that works better.

The pin can be depressed fairly easily using a screwdriver.

Question: do I need to fit a special cap to lock this off? Or will turning the rad control clockwise as far as it goes do the job?

Mike