New bathroom - worse water pressure

[robby71]

My parents had a new bathroom fitted this week and now have really poor water pressure.

The "plumber" replaced the bath and used the taps (mixer with shower head) from the old bath as they were quite new, replaced the taps on the sink with a mixer instead of seperates.
They have a hot water tank downstairs which is only 2 years old and has been working perfect so that's fine.

Now since the new taps the problems were -
hot water from sink is a trickle (was perfect with old seperat tap)
cold water from sink is fine

hot water in bath is ok ( not quite as powerful as before)
cold water is fine
shower attachment is poor (couldn't drown a mouse)

Today the plumber came back and fitted a pump next to the tank downstairs and seems to have connected it just to the bath hot water?
problems now are -
hot water from sink - still a trickle
cold water from sink - fine
hot water from bath is better but not powerful
cold water rom bath isfine
water from shower attachment is better

Why would changing the taps make the sink hot water pressure so poor?
I would have thought a pump fom the tank would up the pressure on all taps upstairs so did he do right by connecting it just to the bath or should he have fitted a splitter of some sort to the sink as well?

Just want to get this sorted for them as they're so upset with the new bathroom and regret having it done

 

[Madrab]

Do they have a big cold water cistern in the loft? If so (sounds like it) and the 'so called plumber' has fitted a mixer tap that chances are it's designed for mains pressure and and the current system can't supply enough pressure, that and it's probably using narrow flexi pipes which compounds the issue.

Basin and bath cold are probably mains - Hot water to basin isn't connected to the pump and still under gravity pressure so as above. He's screwed up, didn't know what the outcome of his changes would do (probably didn't even consider the gravity HW) and thought a pump would sort it, which really is using quite an expensive sledgehammer to crack a nut. but really sounds like he doesn't know what he's doing. Has he been fully paid? if anything is still outstanding then it should be withheld until everything is sorted.

 

[Harry Bloomfield]

Why would changing the taps make the sink hot water pressure so poor?

There are different tap and mixers styles, designed for high pressure (mains), versus low pressure (tank fed). Your 'plumber' seems to have not been aware of this simple fact. Low pressure taps, are usually fine for both low, and high pressures. High pressure taps, are not OK for low pressures, the result is a poor rate of flow from the tap, as you have found.

 

[HERTS P&D]

High pressure taps on a low pressure system?

Andy

 

[roguetrader]

Who supplied the sanitary ware?

 

[robby71]

Do they have a big cold water cistern in the loft? If so (sounds like it) and the 'so called plumber' has fitted a mixer tap that chances are it's designed for mains pressure and and the current system can't supply enough pressure, that and it's probably using narrow flexi pipes which compounds the issue.

Basin and bath cold are probably mains - Hot water to basin isn't connected to the pump and still under gravity pressure so as above. He's screwed up, didn't know what the outcome of his changes would do (probably didn't even consider the gravity HW) and thought a pump would sort it, which really is using quite an expensive sledgehammer to crack a nut. but really sounds like he doesn't know what he's doing. Has he been fully paid? if anything is still outstanding then it should be withheld until everything is sorted.

They have a hot water tank/ cistern? downstairs - in the loft i think there is just a cold water tanks (maybe 20lt)

The "plumber" is someone my dad knows from many years ago, he fitted a bathroom to their last home with no problems, took him over a year to actually start this bathroom as though he couldn't be bothered

 

[robby71]

Who supplied the sanitary ware?

The "plumber" supplied everything