Hot water pressure through the kitchen tap

[robertclarke]

Wondering if someone could help me. I live in a flat with an unvented system. The problem I am having is the pressure through the kitchen hot water tap is really poor, however the bathroom is brilliant.
The distance between the bathroom and kitchen tap (the way the crow flys) is about three metre, so can't understand why this is happening.
Also the amount of time it takes for hot water to come through the kitchen is dredful, about a washing up bowl worth of water before it comes through, but however in the bathroom its nearly instant.

Any ideas what may be causing this?

 

[Gray0689]

It sounds like it's not a balanced supply at kitchen tap if you look see if the mains goes to kitchen tap

 

[easyt]

Although you say kitchen tap is 3m from cistern there is probably 1.5m up and 1.5 m down to tap, so could be 6m of pipe. Also I suspect that there will be a few metre of other horizontal pipe in the loft and so there may well be almost 10m of pipe containing cold water until hot tap turned on to displace this to the sink. Probably 5m or so will be in 22mm and the rest in 15mm. . This may amount to almost 3 litres of cold water before the hot arrives. The hot will also suffer some heat loss heating the pipes. Depending on pipe runs in loft it could b more. It would be easy to suppose that half a gallon to a gallon of cold water could need to be displaced.

 

[robertclarke]

Thanks for the replies, that has answered the amount of cold water coming through first before it gets hot. Never thought of that .

Any ideas about the pressure though I mean it is very poor. You could leave the hot tap on, go drink your tea, get back and it still wouldnt of filled the sink up.

 

[Paulplumb]

Could be a faulty valve or cartridge in the tap. Is the tap installed with flexi hoses? Is the hot one kincked?

 

[robertclarke]

It is installed with flexi hose and from what I can see there is no kincks.

 

[Paulplumb]

Thing to do is disconnect the hot supply before the flexi and direct the flow towards a bucket (obviously control with isolator) if the pressure is good then you know it is the flexi or the tap.

 

[robertclarke]

My mistake just took a bit of the cuboard off and there isnt a flexi pipe after all.

 

[spanner]

Thanks for the replies, that has answered the amount of cold water coming through first before it gets hot. Never thought of that .

Any ideas about the pressure though I mean it is very poor. You could leave the hot tap on, go drink your tea, get back and it still wouldnt of filled the sink up.

Hi there, I understand unvented system have low pressure outlet.But would like to ask, what's is the cylinder size is, and also is it sited below the kitchen sink which you've the low water outlet??

 

[Paulplumb]

Flexi or not I'd disconnect the supply to the tap and run it to a bucket.