Leaking from feeding pipe tap to Combiboiler

[macgyver]

Please excuse my lack of knowledge of correct terminology.
I found a leak from an opening from the pipe feeding into my combiboiler.
Sorry if I am not clear. Will post a picture.
When I tried to tighten or loosen the knob on top with an adjustable Wrench and
a plyer, it is stuck and slipping. Have applied some vinegar soaked cloth on it to loosen the connection.
I do not need this tap. Can I just put some blocker or Sealant in the hole to stop the leak or any other ideas please.
Thanks for looking.

 

[terryplumb]

That's a drain cock. The square shape in the centre should be operated with a spanner to close / open the drain cock ,not pliers.
If tightening fully ,clockwise, doesn't stop the leakage it will need to be stripped down and a new washer / seal fitted.
Or a complete replacement if the square shaft end has been rounded off.

 

[Macgyver11]

Edit: Sorry it's me again. Didn't realise I have an account already and created another one.

Thanks for the reply. Yes, I used the spanner but it was slipping. Will try again after I remove the vinegar soaked cloth and try the spanner with some cloth to hold the square shaft so that it doesn't slip.
Thanks again

 

[gas112]

https://www.screwfix.com/p/arctic-hayes-mt-drain-cock-tap-washers-1-2-5-pack/6666j

take it apart and stick new washer on it

 

[macgyver]

https://www.screwfix.com/p/arctic-hayes-mt-drain-cock-tap-washers-1-2-5-pack/6666j

take it apart and stick new washer on it

Thanks for that. First challenge is to unscrew the square bolt. Have put some vinegar around it. Will get some wd40 tomorrow if it fails.

 

[macgyver]

Unable to unscrew the square bolt. Tried with Adjustable ranch after apllying vinegar and WD40 to it. Will buy the spanner for it. Need to know the size of the spanner I need to buy please. I found this on searching
Drain cock: A 7.9 mm square socket bleed key is suitable for drain cocks.
Thanks

 

[terryplumb]

Did you use an adjustable spanner ? The square looks to be badly deformed in your picture ,and a spanner may not even work if it has been rounded off. I would replace the whole valve if I were you .

 

[macgyver]

Yes I did. Thanks. I think I will need a plumber to fix it. Thank you all for the help.