low pressure tap

zvonkokracun

hi, i have a gravity system in my house. non-pressurized boiler. i had to change the dual lever monoblock mixer tap, bought one advertised to work from 0.5 bar which is a single lever mixer tap. now i only get a trickle of hot water, it feeds from a 22mm pipe the isolation valve is a 22mm full bore one. there is no air in the system and the other warm tap on the house all work fine. my bathroom tap is a single lever monoblock mixer.... it must be a large-bore version ( unfortunately unbranded, i can not remember where i bought it, and being a bathroom tap it wouldn't fit in the kitchen)
short of installing an old style 2 lever tap with 15mm connectors,
can anyone suggest a single lever mixer tap that would work ? 

lesalanos

I appreciate that it doesn't answer your question but worth checking that if there are flexi hoses between the pipe & taps that it isn't kinked and restricting the flow

Moss5

https://www.screwfix.com/p/swirl-loop-single-lever-mono-mixer-kitchen-tap-chrome/82576
I live in a bungalow with gravity supply to the kitchen tap.
This one provided 6-litres/minute on hot flow. Not enough for a good shower, but plenty for washing-up.
I connected below the sink and tested before committing to ownership. If the flow were inadequate, I could return it for a full refund.

Jeepers_Creepers

zvonkokracun said:

hi, i have a gravity system in my house. non-pressurized boiler. i had to change the dual lever monoblock mixer tap, bought one advertised to work from 0.5 bar which is a single lever mixer tap. now i only get a trickle of hot water, it feeds from a 22mm pipe the isolation valve is a 22mm full bore one. there is no air in the system and the other warm tap on the house all work fine. my bathroom tap is a single lever monoblock mixer.... it must be a large-bore version ( unfortunately unbranded, i can not remember where i bought it, and being a bathroom tap it wouldn't fit in the kitchen)
short of installing an old style 2 lever tap with 15mm connectors,
can anyone suggest a single lever mixer tap that would work ? 

Hi Zvon.

0.5 bar is still quite a high requirement.

Stored water like yours provides 0.1 bar of pressure for each metre of height above the outlet. Where is this tap located, and how high is your CWS above this? (Also, every bend and horizontal run of the supply pipe will add resistance and reduce the delivery pressure.)

As Lesalanos asks, any flexi tails used? 

zvonkokracun

thanks jeepers creepers. i do realize i might have around 0.1 bar only. the flexi tails which came with the new tap are ridiculously long. i shall buy shorter ones and see if it make a difference. meanwhile, i found two taps one which works with 0.1 bar ( sadly old style ) and a modern one which is rated with 0.2 bar, the latter one from sinks-taps. i shall post reult. thanks for now. zk

Jeepers_Creepers

What type of tap is this - sink, basin, bath, what? And what style?

zvonkokracun

it is kitchen sink tap. with long tails and ( what must be my problem ) almost 1 Meter of pull out spray, it is looped, because of the heavy weight in the middle which makes the spray snap back I to the tap after use. 

greyteam1959

Your tap might be fed from a 22 mm pipe but the flexible tails that screw into the tap will probably be 10 mm or 8 mm.
The length of the tails is nothing to do with it.
You are never going to get good water flow.

zvonkokracun

hi greyteam 1959... i have come to the conclusion myself. have ordered a mixer tap which delivers 5 liters with 0.1 bar pressure.... i don't think i have less than that.  sadly no pull out spray on that one. i might install such, in addition, on the cold feed only, because it is very handy for lots of jobs. thanks anyway.