Tap diameters & water pressure

[wurzelplummidge]

Hello, I bought a bathroom sink and tap from IKEA as part of a DIY refurb. The new tap is a monoblock with 12mm x 15mm connectors and it replaced a pair standard 15mm ones. As it's an old house with a gravity fed system the water pressure is not amazing but hot water from this new tap is significantly crapper than the 22m bath taps just after it in line, and also the kitchen's 15mm mixer tap. The cold water is fine, it's just the hot.

So I'm thinking these 12mm mixer taps are not really any good for low pressure systems, wish I could have been advised that before shelling out :-\ I'm now looking at getting a new tap, but most retailers don't list the connector size, or say things like "pipe size required 15mm" (could mean 12 x 15mm) or "M10 x 15mm screw-in copper connecting pipes" ( I'm assuming M10 means 10x15mm). I havn't measured the water pressure so can't really go by bar ratings but am pretty convinced a 15mm is the way to go.

Any tips for good places to buy a nice-ish 15mm bathroom sink tap? Thanks in advance!

 

[ChrisR]

Posh taps are often designed for Continental (higher) pressures.
1 bar is 10 meters head. Look for something which is recommended for 0.2 bar and up.
Obviously if the hot is much worse than the cold and it ultimately comes from the same head (pressure) then there's resistance in the pipeline somewhere, so look for half-closed valves etc.
What flow rate are you actually getting ( litres per minute)?
It won't be all down to the size of the tap connector but they do make a contribution. A lot of resistance is inside the tap itself.

Look at Bristan, Iflo, Deva.

a nice-ish 15mm bathroom sink tap?

Bathrooms have BASINS, not sinks! It matters when you're looking for taps

 

[wurzelplummidge]

Thanks Chris,

Good news to hear that the size of the tap tail/connector doesn't affect things that much, that means I can call off the search for a bigger diameter one.

Will try to work out the bar rating & flow rate and compare with tap specs.

Plus I'll stop calling the basin a sink!

 

[Jake1886]

You simply need a low pressure basin tap or taps.

 

[Whitespirit66]

Monobloc bathroom mixers with 2 cross heads on them with conventional valves (as opposed to ceramic discs) are more suitable for low pressure. Single lever, ceramic disc monoblocs tend to kill the flow a bit.

Tapstore specifies the min pressures needed for their taps in the spec.

http://www.tapstore.com/acatalog/Bathroom-Taps.html

Also, losing the isolation valves if you have fitted them to the pipes to the tap will help. Even fully open, they can restrict the flow quite a bit.

 

[ChrisR]

Be careful, some makers list 0.5bar as "low pressure". That's 2 floors.

 

[wurzelplummidge]

Thanks a lot for all the info + tips everyone, this forum is amazing.

I'll keep my eye out for a low bar tap and see if there's anything I can do to improve the pipework.

Interestingly adding the supplied aerator helps a lot by making the most of the water so washing hands is good, but slow to fill the sink and get warm... maybe I can add some lagging.

Cheers!