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Mar 12, 2025
2
0
1
Greater Manchester
Member Type
DIY or Homeowner
Hi - I'm a baffled DIY plumber! I wish to renew my side-entry toilet cistern inlet valve as it's noisy and filling up slowly. The inlet valve plastic pipe (PS they say brass ones are better when it comes to renewing) which comes out of the cistern is 3/4 inch (I unscrewed and measured it) which then attaches to the cold water flexible hose input. I literally trawled all the internet - or so it seemed - to find a new inlet valve to fit but they all seem to be either 1/2 or 3/8 inch. I could not find any 3/4 inch. The inlet valve is old (well over 15 years) so is it obsolete or am I being thick and missing something glaringly obvious? Any advice appreciated. Thank you
 
Your valve is 1/2", you've measure the outside of the thread, the size is the hole through the inside.

3/4" and many other sizes large exist, but are only used on commercial water systems.
 
Your valve is 1/2", you've measure the outside of the thread, the size is the hole through the inside.

3/4" and many other sizes large exist, but are only used on commercial water systems.
Thank you for the reply greatly appreciated. I must admit I wouldn't have had the plastic width as that much, but it is quite thick. Is there any side inlet valve you would recommend for easy to fit and also maybe adjust if required?
 

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