Gas fitter masquerading as a plumber.

[Callumjb]

Have you tried seeing if there is an aerator on the end of the tap outlet. These often restrict flow and especially will affect gravity hot water

 

[dan_the_plumber]

You seem to have focused on pressure. Is this 1.5 bst static pressure or dynamic pressure?
Also I tend to find that what you shouldmainly focus on is flow rate, not pressure 🙂

 

[ShaunM81]

There is much nonsense talked about tap flow rates. There is no formal definition of low or high pressure so one manus hi is another's lo. It's literally a lottery. From what you say in your original post, NO 1/4 turn tap or single lever tap will give you even reasonable flow rates. You are better off converting 1/4 turn to traditional multiturn. Yes, it can be done.

What you are trying to achieve is flow rate i.e. how much water flows into the bowl in a set period. While pressure has an impact on that, its the dynamic pressure (i.e. when open) that is counts not the static pressure (when closed). The static will always be higher.

Flow rate, just like through a combi, is deeply affected by ANY and EVERY restriction. For a low pressure HW system like this one then you MUST use hard tap tails (can be bought seperately) and full bore iso valves. Check EVERY valve on the supply pipework cos ANY valve that is not full bore will utterly compromise flow. If you had 35mm pipework from the cylinder to the tap and a cheap iso with its 8mm hole then your pipework is effectively 8mm in dia. It's NOT the same as gas.

HTH 😉

Brilliant thank you

 

[TMHM]

Just an aside here, but I got caught out buying a tap in France, where they use mains pressure hot and cold water, the flow rate out of the tap on the hot side was unusable when installed in the UK.

 

[ShaunM81]

Just an aside here, but I got caught out buying a tap in France, where they use mains pressure hot and cold water, the flow rate out of the tap on the hot side was unusable when installed in the UK.

Why couldn’t it be used exactly? Just curious

 

[TMHM]

Just that the flow rate was so bad and so different from the cold side. I assume that there must have been some form of prv, but why it affected only the hw side, I am not sure.