2x internal stop cocks stuck open

Joined
30 Dec 2019
Messages
39
Reaction score
0
Country
United Kingdom
Hi everyone,

I have 2 inline stop cocks for the cold water supply under the sink. I wanted to check that they were operational in case of a flooding emergency. However, both seem to be pretty well stuck open.

Being in London, I am thinking this is a limescale related issue. In fact you can actually see limescale build up around the valve (god knows how long ago they were last turned!)

I have attached photos.

Would it be unwise to try and undo the packing box and then try to turn them slowly given their state? If I am likely to do more harm then good attempting this, then I would rather just get a professional in to replace.

Thanks!
 

Attachments

  • IMG_20200404_125508.jpg
    IMG_20200404_125508.jpg
    137.9 KB · Views: 256
  • IMG_20200404_125535.jpg
    IMG_20200404_125535.jpg
    94.4 KB · Views: 252
Sponsored Links
They look fairly modern so should turn. Clean off the surface crud and try turning with a lever using a back and forth motion. As you turn the tap , always keep doing the back and forth - it clears the screw threads as you go. Obviously don,t force or the spindle will break.
As a backup check if there is a stopcock outside the flat in the riser - you'll need the water turned off anyway if you decide to replace the stop cock.
 
Spray the scale wth WD40.
Take the screw out of the handle and whilst gripping the tap body with pump pliers use an adjustable spanner to try and free them...you could try tightening first to break the scale.
Otherwise, isolate outside and just replace the headgear (and salvage the headgear from a new stopcock)...no need to change the whole stopcock normally.
 
Sponsored Links
In both cases, the limescale is around the gland nut. There is probably nothing else wrong with the taps. Approach would be:
1. As stated above, make sure you can turn the water off elsewhere in case of (unlikely) disaster.
2. For each tap in turn:
2a. Slacken the gland nut (its the smallest hexagon just where the spindle goes into the tap body), about 1/4 to 1/2 turn.
2b. Close the tap in the usual way, with a bit of extra leverage as necessary.
2c. When closed, take the handle off (if you can), and undo and remove the gland nut. If you can't get the handle off it will only limit the amount of cleaning you can do.
2d. Clean / polish the spindle where it goes though the gland nut to remove any roughness and limescale.
2e. Make a "string" of PTFE tap (the ordinary one, not the thicker, gas, one). Start with a string about 200 mm long.
2f. Wrap the PTFE around the spindle, and push the coiled tape down into the body of the tap.
2g. Reinstall the gland nut, and tighten firmly, but not so tight you can't turn the handle.
2h. Put the handle back on and open the tap. If there is a slight weep from the gland, tighten it up a bit, but again, not so much that you can't turn the handle.
2i. If there is still a weep, repeat 2e through 2h, but use more PTFE tape in "string" form.

Its worth noting the limescale only forms visibly where there is water, so its likely the gland nuts have been weeping for a while.
 
Thanks for your detailed replies. I am going to give it a go but check I can isolate from outside first.
 

DIYnot Local

Staff member

If you need to find a tradesperson to get your job done, please try our local search below, or if you are doing it yourself you can find suppliers local to you.

Select the supplier or trade you require, enter your location to begin your search.


Are you a trade or supplier? You can create your listing free at DIYnot Local

 
Sponsored Links
Back
Top