Simple Plumbing Question

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Meeja

Original Poster:

8,290 posts

254 months

Tuesday 13th September 2011
quotequote all
As far as DIY goes, I am pretty competent in most aspects..... with one exception, plumbing.

However, always prepared to have a go......

The bath tap mixer/shower thingy on the bath at Meeja Towers has finally failed (Mrs Meeja has hated it since we moved in ten years ago) and whilst a new bathroom is in the pipeline, it is still a good five years or so away (lots of other jobs to do first!)

So I need to replace the bath taps as a mid-term measure, and don't really want to have a plumber out unless absolutely necessary.

Because of the tap position in relation to the bathroom, the access to the 'under-bath' pipework is very good.

The current mixer is attached to the 15mm copper feeds via flexible braided hoses.

Couple of questions.....

Would it make sense to fit isolation valves onto the copper feeds at this point? (None there at the moment)

When buying new taps, do they all come with flexible hoses?

Are the threaded part of the taps (that go through the bath surface and have a tightening nut fitted underneath) all a standard size? ie when I remove the current micer, will any new tap I buy fit the same hole? - And if I chose a mixer tap rather than individual hot and cold, is the dimension between the inlets standard?

A quick look at Screwfix threw up these which Mrs Meeja quite liked..... what is the difference between the 3/4 and the 1/2?

Thanks in advance.....

TooLateForAName

4,833 posts

190 months

Tuesday 13th September 2011
quotequote all
Taps come in different sizes - those you've linked to are different sizes - hence one described as basin, the other bath. The size is the size of the fittings - 1/2 inch or 3/4 inch in this case.

Simpo Two

86,911 posts

271 months

Tuesday 13th September 2011
quotequote all
Meeja said:
Would it make sense to fit isolation valves onto the copper feeds at this point? (None there at the moment)
A sensible bit of future-proofing IMHO, but choose ones with the biggest bore - some are almost straight through.

Meeja said:
what is the difference between the 3/4 and the 1/2?
Page not loading for me but in my experience 1/2" is for basins and 3/4" for baths (need more flow).

Meeja

Original Poster:

8,290 posts

254 months

Tuesday 13th September 2011
quotequote all
TooLateForAName said:
Taps come in different sizes - those you've linked to are different sizes - hence one described as basin, the other bath. The size is the size of the fittings - 1/2 inch or 3/4 inch in this case.
Ah - gotcha. Didn't spot the "Basin" bit in the title of the 1/2.

So the 3/4 on refers to the size of the threaded pipe that goes through the bath?

Meeja

Original Poster:

8,290 posts

254 months

Tuesday 13th September 2011
quotequote all
Simpo Two said:
Meeja said:
Would it make sense to fit isolation valves onto the copper feeds at this point? (None there at the moment)
A sensible bit of future-proofing IMHO, but choose ones with the biggest bore - some are almost straight through.
Biggest bore? Now you have lost me! (I imagined that one 15mm isolation valve was pretty much the same as the next one!)

Could you give me a little more detail?

Gingerbread Man

9,173 posts

219 months

Tuesday 13th September 2011
quotequote all
Isolation valves come in different shapes, sizes and for different pressures (mains/ low pressure).

For example. Full bore:



A reduced bore:



Notice how the middle section between the two compression nuts changes.



1/2" and 3/4" refers to the threaded shank coming out of the taps. The former being basin and the latter bath/ kitchen. This used to be mostly the norm, but now-er-days a lot of taps are monoblock taps which are different again.


Not 100% sure how your bath taps connect to the pipework but you mentioned flexible hoses. I'm assuming that these are attached to the threaded tails of the taps and then in turn to the pipework. They can attach to the pipework in many different ways, push fit, compression, compressed onto a straight coupler. If they join onto the threaded section of a straight coupler, you could swap this coupler with a isolation valve and then Bobs your Mothers Uncle.

Either way, you'll have to drain down.


Most bath taps come with standard 180mm centres, so you should be dandy buying a new set off the shelf. But worth a double check just in case. If you have a plastic bath with a separate hot and cold tap as opposed to a mixer, these could have been drilled at any measurement, so bear this in mind.

Also, bath taps tend not to come with flexible connections, just threaded tails that you then connect on to.

Edited by Gingerbread Man on Tuesday 13th September 18:16

Simpo Two

86,911 posts

271 months

Tuesday 13th September 2011
quotequote all
On the subject of bore, if your system is gravity fed, make sure your flexitails don't have little flap valves in them - that reduces flow even more. Throw them away and buy normal ones. It's all about the size of the hole. The bigger it is, the quicker your bath will fill.

Worth pointing out, before you rush out and buy sexy taps, that you are not putting 'high pressure' taps on a low pressure (gravity fed) system or your flow will be knackered.


Meeja

Original Poster:

8,290 posts

254 months

Tuesday 13th September 2011
quotequote all
Gingerbread Man - thanks for that. Very useful.

At present, there are two 15mm pipes coming up through the floor underneath the bath (hot and cold feeds)

There are compression fittings on the end of the pipework that converts the pipe end to something that the flexible hose is screwed onto.

Just having had another look, you are correct - the other end of the flexible hose is simply screwed onto the tap tail (which sits about three or four inches underneath the bath surface)

So in essence, I could remove the compression adapters, and replace with (full bore) compression fitting isolation valves, and reuse the flexible hoses onto the tails of the new taps?

To isolate the cold, I'll simply turn the main stop cock off.... hot water is fed from a condensing boiler.... once the cold feed is isolated where it comes into the house, can I simply run the hot tap until it stops, or should I turn off the boiler as well (so that it doesn't try and supply hot water when there is no cold supply coming in?)

What could possibly go wrong?

biggrin

Meeja

Original Poster:

8,290 posts

254 months

Tuesday 13th September 2011
quotequote all
Simpo Two said:
Worth pointing out, before you rush out and buy sexy taps, that you are not putting 'high pressure' taps on a low pressure (gravity fed) system or your flow will be knackered.
Gravity fed means a tank in the attic from which the water comes from?

Not in my case.... cold feed direct from the incoming main, hot direct from the (condensing) boiler

So am assuming that something that is "Suitable for high pressure and low pressure systems" would be ok?

Gingerbread Man

9,173 posts

219 months

Tuesday 13th September 2011
quotequote all
You have a high pressure system as the hot and cold are at mains pressure. Using 15mm copper pipe always to the taps and removing the flexible connectors would be best, but as it's a high pressure system, I doubt you'd notice.

In regards to the flexibles and isolation. If you get a flexible connector with 3/4" one end ready to join onto the bath taps and with 1/2" the other, both female ends, then you could join the 1/2" female to the male external threaded section of an isolation valve. Job's a gooden.
If they go from 3/4" (taps) to 15mm compression fitting, you'll just need to cut in a compression isolation valve.


But in all honesty. It's a combi (mains) system you are running, so turning off the mains therefore kills both the hot and cold (leave taps at lowest point open till water ends). This isn't really that hard (as long as you stopcock works). So if you can't be bothered with the isolation, it wouldn't be a massive problem. Not like you have to play around with a faulty gate valve or drain the who tank like a gravity setup.

Arthur Jackson

2,111 posts

236 months

Tuesday 13th September 2011
quotequote all
Flexi-hoses = Wrong.

Meeja

Original Poster:

8,290 posts

254 months

Tuesday 13th September 2011
quotequote all
Arthur Jackson said:
Flexi-hoses = Wrong.
Understand that thinking.

Will re-look at it tomorrow.... the current pipework coming up from the floor is not long enough to reach the taps (around six inches or so short) I will need to replace the pipe (if I can get at the fitting where it spurs off the hot and cold feeds) or will need to extend the pipes to meet the bottom of the taps

All seems relatively straightforward, even to someone who doesn't "do" plumbing!

Thanks for all of the advice and comments - all extremely useful!

Simpo Two

86,911 posts

271 months

Tuesday 13th September 2011
quotequote all
Arthur Jackson said:
Flexi-hoses = Wrong.
But ideal for DIYers and anyone who can't blowtorch copper piping to millimetric accuracy.

Meeja

Original Poster:

8,290 posts

254 months

Wednesday 14th September 2011
quotequote all
Simpo Two said:
But ideal for DIYers and anyone who can't blowtorch copper piping to millimetric accuracy.
My soldering skills are limited to circuit boards.... so it will be compression fittings for me!

Meeja

Original Poster:

8,290 posts

254 months

Wednesday 14th September 2011
quotequote all
Gingerbread Man said:
You have a high pressure system as the hot and cold are at mains pressure. Using 15mm copper pipe always to the taps and removing the flexible connectors would be best, but as it's a high pressure system, I doubt you'd notice.
We bought the house from a chap who was a semi-pro property developer, and in all honesty, the quality of anything underneath floorboards that I have found over the years has always been first class.

The system WAS gravity fed until about three years ago, when we extended the house, and part of the works included relocating and replacing the old boiler system with a Combi system, thus removing two storage tanks from the attic.

With the info you have given me, and confirmed by others, I'm surprised that the previous owner used flexible hoses on the bath taps.... having now checked other basins in the house that are still as they were when we purchased, none of them are felxible, they are all taps direct onto (very neat) pipework.

But takes all sorts I suppose....

So, job for the weekend is to replace the taps, install isolation valves, and remove the need for flexible hoses.

Wish me luck!

Ferg

15,242 posts

263 months

Wednesday 14th September 2011
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COMBI!!! yikes

Get shot of those flexi-hoses, mate.

Meeja

Original Poster:

8,290 posts

254 months

Wednesday 14th September 2011
quotequote all
Ferg said:
COMBI!!! yikes

Get shot of those flexi-hoses, mate.
That's the plan Ferg!.... Going to do it at the weekend.

Regarding the Combi, I have to say that since it's install, it has been superb. No issues at all. Gas bills also significantly lower than with the (admittedly old) system that it replaced, despite the house (and heating system) increasing in size by over 50%!

Meeja

Original Poster:

8,290 posts

254 months

Sunday 25th September 2011
quotequote all
Forgot to update this.... Flexible hoses removed, old mixer tap removed, copper pipework cut back, full bore isolators fitted to both hot and cold, new copper pipe fitted up to the bottom of both new taps.

Amazing what difference the full bore has made, flow rate on both hot and cold now significantly better.

Oh yes.... No leaks either (I did it last weekend, and have just removed the bath panel again and triple checked.... Not a damp patch anywhere.

Quite proud of myself to be honest, as I am most definately not a plumber!

Job jobbed!!

Arthur Jackson

2,111 posts

236 months

Sunday 25th September 2011
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Nice work. Flexi-hoses are just a bodge and substandard. Great source of leaks too.

dirkgently

2,160 posts

237 months

Sunday 25th September 2011
quotequote all
Arthur Jackson said:
Nice work. Flexi-hoses are just a bodge and substandard. Great source of leaks too.
Great source of beer tokens for me thoughsmile