Reduced hot water flow after refit.

[Colinscat]

Hello. As in the title I have just had a bathroom refit which involved the basin being moved 90° a metre away from its original position. Since the work has been done the hot water flow from the wash basin has gone down drastically. To put a rough figure about 90% reduction. The isolation valve under the sink is fully open. The hot water flow from the bath is acceptable and there is no change in the hot tap in the kitchen.
The fitter is coming back in the morning for snagging so he will have a look but can any plumbers offer me any advice or possible cause just in case the fitter doesn't know. He is a bathroom fitter but whether he is a fully qualified plumber I don't know.
I'd appreciate any expert advice.
Thanks.

 

[Colinscat]

Hello. As in the title I have just had a bathroom refit which involved the basin being moved 90° a metre away from its original position. Since the work has been done the hot water flow from the wash basin has gone down drastically. To put a rough figure about 90% reduction. The isolation valve under the sink is fully open. The hot water flow from the bath is acceptable and there is no change in the hot tap in the kitchen.
The fitter is coming back in the morning for snagging so he will have a look but can any plumbers offer me any advice or possible cause just in case the fitter doesn't know. He is a bathroom fitter but whether he is a fully qualified plumber I don't know.
I'd appreciate any expert advice.
Thanks.

Read more: https://www.diynot.com/diy/threads/reduced-hot-water-flow-after-refit.532007/#ixzz63NptHfwv

 

[ianmcd]

If your new taps are fitted with flexible hoses these are very restricting and that will be the most likely cause

 

[Newboy]

Is your hot water supply pressurised (unvented cylinder/combination boiler)?

Are the taps suitable for the system they have been fitted too (HP/LP)?

What type of in-line isolators for the basin taps? (cheap & cheerful or full bore)

Have flexible tap connectors been used for the basin feeds?

This thread should be in Plumbing & Heating - I'll ask mods to move

 

[Colinscat]

Hi. The hot water is supplied from a cylinder. The bathroom suite was purchased from Wickes. It's a monobloc tap. The isolation valves look bog standard to me and are on flexible tap connectors.
Thanks.

 

[Colinscat]

Yes they are flexible tap connectors. Thanks.

 

[Newboy]

The hot water is supplied from a cylinder.

If it's a cylinder with tanks in the roofspace then it's probable that you have a Low Pressure (LP) hot supply.

The water channels in monoblocs are narrow and will reduce flow. The monobloc tap will have fairly restrictive tails (either copper or flexible connectors).
If cheap isolators have been used then these will restrict the flow even more.

Do you have a link to the tap and did you supply it or did the fitter supply it?

 

[Ryler]

Your new taps might not like gravity pressure.
Gravity likes full bore. Isolators can be restrictive also.

 

[Deleted member 267285]

If it’s a vented hot water system, it could be as simple as a snapped gate valve, cwsc not filling up, debris at tap filter

 

[Madrab]

Sorry @The Novice but if it was any of them it would show up at the other taps too, that and there probably wouldn't be a filter on the monobloc tap either unless it's a waterfall.

It will probably be to do with the tap itself or the ISO valve, especially if the other outlets are fine.

 

[Deleted member 267285]

Sorry @The Novice but if it was any of them it would show up at the other taps too, that and there probably wouldn't be a filter on the monobloc tap either unless it's a waterfall.

It will probably be to do with the tap itself or the ISO valve, especially if the other outlets are fine.

Thanks for that, just re-read, must have missed the bit about bath and kitchen taps . The filter I was referring to is the little (what I call a filter) bit inside of a quarter turn tap, which has about 3 lines?

 

[ianmcd]

My money is still on the 10mm flexis restricting it