Problem with mixer tap

Banjo Carney · 26-06-2025 08:18PM #1

Hi I have a small mono mixer tap on a basin in a bathroom. The hot water works perfectly but there's barely a dribble from the cold. The cold tap on the bath next to it works perfectly.

I thought the problem was the cartridge so I put a new one in it today but it's still the same hot perfect, just a dribble from the cold. I followed the advice in videos to solve air locks but no joy.

Is a new tap the next step, is there any test I can do to confirm it's the tap. Thanks in advance.

Banjo Carney · 02-07-2025 07:21PM

Anybody ? Is there anything else that can be the problem with the tap itself besides the cartridge that would cause no water from the cold side.

Esel · 02-07-2025 07:41PM

Are the bath and sink served by the same pipe?

IANAP

Banjo Carney · 02-07-2025 07:55PM

https://www.boards.ie/discussion/comment/123599686#Comment_123599686

They are yeah

Esel · 02-07-2025 08:19PM

Just guessing now. It might be some kind of airlock.

You could try blocking the mixer outlet with a wet cloth firmly held against the outlet, and turn on the cold and then hot taps. The good pressure from the hot tap might clear the possible airlock.

winklepicker2025 · 02-07-2025 08:24PM

might be build up in the cold water supply pipe restricting the flow too the tap.

If possible open any fitting along the supply pipe and see if you get a decent flow.

If you do get a decent flow problem will be the tap,if a slow flow your possible a air lock in the supply pipe or kink in the supply pipe restricting the flow rate

Banjo Carney · 02-07-2025 08:37PM

https://www.boards.ie/discussion/comment/123599778#Comment_123599778

Thanks for your suggestion, I've done that several times to no avail

Banjo Carney · 02-07-2025 08:41PM

What could be the problem with the tap though apart from the cartridge. With the cartridge out I turned the cold water back on. The body of the tap filled with water but didn't overflow into the basin. Is that an acceptable flow rate

winklepicker2025 · 02-07-2025 08:46PM

very slow by the sounds of it,

Could be build up of limescale or debris.

Is it an old house ?? Lead water main maybe ?

Banjo Carney · 02-07-2025 08:51PM

It's 1990s build so not lead water main. It's not a hard water area either. I find it hard to understand how there could be debris in the small run of pipe from bath to sink, but you maybe right. It will be great fun if you are the pipes are behind tiles 😞