22mm feed pipe to bath - Required?

[toptec]

Hi Gents

Plumbing in a new bath, 30 year old cast iron one, weighs a ton now removed, revealing a 22mm hot water feed to the bath tap. This is then reduced further along the run to 15mm serving the sink.

My question is: Do I need to fit a 22mm feed to the new bath or can I reduce it to 15mm where it enters the bathroom and continue 15 mm to the sink?

The system is on an immersion at present although at some point in the near future I will be having a combi system fitted.

Ta lots

 

[Bahco]

15 mm will be better for combi supplied hot water and will save a little energy.

 

[John M]

It will fill slowly with the current immersion setup if its supplied with 15mm ....... I have no idea what will happen when your combi is fitted

 

[Bahco]

At some point in the near future I will be having a combi system fitted.

 

[John M]

At some point in the near future I will be having a combi system fitted.

Ah it will be crap with the combi fitted too huh ...... umm

Why do people buy this carp

 

[Blasphemous]

My question is: Do I need to fit a 22mm feed to the new bath or can I reduce it to 15mm where it enters the bathroom and continue 15 mm to the sink?

The system is on an immersion at present although at some point in the near future I will be having a combi system fitted.

Ta lots

To achieve decent pressure with your current set up you really should keep the 22mm. I suspect you have already guessed, reducing down to 15mm will affect the pressure.

The system is on an immersion at present although at some point in the near future I will be having a combi system fitted.

Bahco is right, '15 mm will be better for combi supplied hot water and will save a little energy'.

But how long is the run of pipe? Have you got one of them palatial bathrooms? If not, the 'new' 22mm should be fine when you get your Combi..... Unless you got lots of peeps using hot water at the same time in the house, then the Combi will Struggle.

 

[toptec]

blasfemous

The Combi will be fitted in the next 2-3 months, piggy bank permitting.

Currently the DHW is supplied from immersion on the ground floor, ( I'm renovating a bungalow), to the loft, say 2.5 metres, across to the bathroom ceiling, say 4 metres then back down into a 3m X 6m bathroom. Total run of about 9 metres.

The run when the combi is fitted in the loft will actually be a lot shorter, probably 5 metres.

Multi use of the DHW will be minimal, me and the significant other.

Oh and thanks for advice guys.

 

[gas4you]

Pipe size affects flow rate, not pressure