kitchen mixer low flow rate on hot

[loafer]

new flat=new headaches

tap astracast mixer
hot water gravity fed (1 storey flat)
hot to bath 22mm flow ok
hot to basin 22mm red. to 15mm approx 1.5 ms. flow ok

HOWEVER!!??
hot to sink 22mm red. to 15mm approx 3 ms. flow rate crap (about 3 litres per min.)

self tapping wash mac tap... ahaa!!! methinks cut out disc is blocking port(s) on hot side of mixer!!
strippped down tap completely
wire mesh not blocked
ports not blocked
broddled some 13 amp fuse wire into tap body no blockage
took off mixer blew threw it no blockage
dismantled from sink.. check tails (15mm to 8mm) no blockage

using the flex connecting 15mm copper to tap tail..ran off a full 10l bucket from the hose in a minute

reassembled and managed ... once again to get about 3 litres... a pitiful trickle.

Totally befuddled.

only thing i can think is previous owner put on a dedicated high pressure tap by mistake and just put up with it. But although ive seen lp and hp bath fillers never seen a kitchen sink option of hp/lp.

 

[JohnD]

you will get the best flow through a simple upright sink tap in the largest size you can find.

I don't know if you can get these in 3/4" (22mm) size

Mixers (especially continental ones) are bound to impede flow a bit, and 8mm tails imply small waterways.

If you have any of those service valves with a little ball inside, the hole is small and will restrict the flow w bit (you can get full-bore ones with a lever to operate). So will foexible braided tap hoses.

Sadly a gravity flow in a single-storey flat is never going to overwhelm you with the strength of its flow.

I have 8mm tails on my sink mixer and get 3 galls/minute on mains pressure. I get the same from upright sink taps in the utility room, though.

 

[loafer]

cheers.. flat has obviously, recently had some modernisation done prior to me buying... spose its just a screw up that some1 was willing to tolerate before selling the problem on to me.

 

[TicklyT]

The kitchen tap that she who must be obeyed chose was sold as 'not suitable for pressures below 0.5 Bar'. We have a gravity system, with the tap about 5 Metres below the CWSC. It works, but only just!

In a flat the hot pressure would probably be about 0.1 to 0.2 Bar..... No chance!

I expect a simple sink tap designed for a gravity system would give a considerable improvement without going to the extreme of using a 22mm bath tap. The feed is probably 15mm, so a 22mm tap would not be warranted anyway. Keep well away from anything with small bore tap tails!

 

[JohnD]

Tell her "Woman, know your limits."

Plumbing is a boy's job.