Leaking Rad

blackstar

Please can anyone give me some advice?

I have discovered exactly where the water is dripping from, it is coming from where the arrow is pointing too on my bathroom rad. All other valves are dry. What is that part called that the red arrow is pointing to do you know? When I turn that part with my hands (which I think turns rad on and off) lots of water drips out. When I do not turn it, it drips every mins or two.

Is it something that a total amature can fix? If so how? Does this part even come off? I tightened the other valves but made no difference, still leaking from that same place.

please see pic.

<a href="https://ibb.co/JrpJ8Dd"><img src="https://i.ibb.co/XF5R6c4/bathroom-rad-leak-2020-nov.jpg" alt="bathroom-rad-leak-2020-nov" border="0"></a>

lord_blackadder

You would need to drain down the system to change it out , these can be biught from b&q quite cheaply ,you would then have to refill the system and remember to add corrosion inhibiter

grumbler

The part is called lockshield valve

https://www.screwfix.com/c/heating-plumbing/radiator-valves/cat830962#category=cat13470004&packsize=1

IIRC, you'll need PTFE tape to connect it to the radiator

https://www.screwfix.com/p/ptfe-tape-12m-x-12mm/76841

Jeepers_Creepers

The cover that you are turning to control the rad, that should come off - if it has a screw in the centre of its top, then undo this first - then try pulling it straight off. 

Underneath is the spindle and where this enters the valve body there will almost certainly be a nut surrounding it. Tighten that nut an eighth-turn clockwise. See if that does the job.

Set the control to give the required rad temp - and don't touch it...

blackstar

OK I took cap off and saw where it was leaking. I removed the screw and put in some PTFE tape and tightened it back up again. Do you think this will work?

Plz see pics

grumbler

there are no pics

Jeepers_Creepers

If you undid the nut surrounding the spindle base, wrapped a good few turns of PTFE tape like rope around the spindle (clockwise, ideally), slid that down inside and then replaced the nut tweaking it up just so, then - yes - good chance you've fixed it :-)

blackstar

Jeepers_Creepers said:

If you undid the nut surrounding the spindle base, wrapped a good few turns of PTFE tape like rope around the spindle (clockwise, ideally), slid that down inside and then replaced the nut tweaking it up just so, then - yes - good chance you've fixed it :-)

Exactly what I did. The part at the end I did remove it fully and it is a spindle. Which I then screwed the spindle back inside but as I was screwing the spindle back in I added the tape inside and around the screw and tightned it. I had a hell of a time as the spanner just would not work well, just would not connect well with that screw for some reason. Seems like the screw has a odd shape, maybe its just because its so thin. The screw is soooo thin the spanner kept slipping off??? what type of spanner is the right one for that screw.
I was worried when I removed the spindle water would come rushing out but it was just an empty wet area that the spindle goes into. Guess some water must get into that area over time and then leaks out? the  

You know if you drain dowen the central heating system, do you have to do something to all the rads in the house or just one rad?
Hoping it will not come to that. 
Did pics work?

blackstar

OK still leaking from point 1 and the arrow below. Ive been advised to do the following, would you all agree?

Leak is coming from inside the chrome body, so I have been told where I need the tape is not visible from the outside of the valve,it's inside the chrome body. I need to take out the nut completely then I will see down inside the chrome body ,and where the spindle disappears into the gland. That's where the PTFE tape needs to be. Do you agree? Dont see how I can actually wrap the tape around anything as its inside, will prob have to just poke it right down as far as it will goI I did put PTFE tape on one part as you can see from pic, but its still leaking in part 1 and/or part 1B from the picture attached. 

Jeepers_Creepers

Yup - your second method is correct :-)

That nut is a 'gland' nut - it squashes a seal (traditionally hemp or similar) inside the chrome body which then spreads out and seals nicely around the spindle.

So, DON'T unscrew the spindle. Just leave it be. (And if it has been turned fully clockwise to shut off that valve, then no water will come out that end anyway.) Now undo that gland nut - yes, the one you removed before - using any neat-fitting spanner or even a socket. Yes it's slim, but it has nice sharp flats so no excuse... Remove it fully, and look at its bottom - it has a flat circular surface, yes? Well, you are now going to make an O-ring that this surface will press down on and squish. 

Remove all that PTFE tape and get some fresh stuff. Give the tape a few twists so's it's more like 'rope' rather than flat tape, and wind it clockwise a good half-dozen times around the spindle base, also winding it over itself too to end up with a PTFE 'ring' 6mm-ish wide x 3mm-ish thick (not at all critical - you are just making a type of O-ring).

Don't wrap it too tight, tho', just enough to build up a nice PTFE O-ring. You are going to have to push that PTFE 'ring' right down the spindle to inside that chrome body (it'll only go as deep as the thread of that nut is long). Now replace the gland nut and do it up until it seats on the PTFE - do NOT do it up 'fully'. Open the valve - ie turn the spindle anticlockwise - almost full and wait for a drip. Once it's dripping, tighten that gland nut slowly until the drips stop. Then give it a final, ooh, quarter-to-half turn. 

Finally shut off that valve again to the point where it gives you the heat you want (what sort of valve is on the other end - which one do you use to control the output temp?) 

Jobbie jobbed. If it drips again, just tweak that gland nut down a further quarter-turn to squash the tape more. 

(Do you have any silicone grease or spray? If so, add some to the PTFE collar too before replacing the gland nut, and a smear on spindle and nut threads too.)

blackstar

I just had a tradesman out and he said that it needed a new valve fitted. He said the system will need to be drained via a radiator. Does he need to do something with all the radiators or check all the radiators in order to drain the system? 

Will he need to turn water off also?

Thanks