Possible to convert bathroom 2 taps with one tap mixer?

[Simon Ferrol]

The hot water in my bathroom sink is too hot. The sink is too small to
accept a plastic bowl to do the mixing. Water temperature cannot be
changed due to electric boiler having pre-programmed temperature.

The taps are 40cm apart from each other. Sacrificing one tap, is it
possible to replace one of the two taps with a mixer tap and bring the
water from the other tap with a flexible pipe?

If so, can it be done DIY?

If not, what would it cost me to have the new sink and mixer installed
by a plumber? I need to go for the cheapest option.

[Colin Bignell]

A sink plug, so you can mix the water in the sink?

--
Colin Bignell

[GB]

On 28/08/2023 19:46, Simon Ferrol wrote:

> The hot water in my bathroom sink is too hot. The sink is too small to
> accept a plastic bowl to do the mixing. Water temperature cannot be
> changed due to electric boiler having pre-programmed temperature.

The cheap, cheap, cheap solution is a plug! Then run hot and cold into
the basin, and wash. You don't have to wash under running water.

>
> The taps are 40cm apart from each other. Sacrificing one tap, is it
> possible to replace one of the two taps with a mixer tap and bring the
> water from the other tap with a flexible pipe?

No. The tap holes are the wrong size. You'll break the basin getting the
old tap out. And so on. It's a nightmare job.

What you might try is a thermostatic valve under the basin, but they
aren't cheap. You'd fit it to the feed to the hot tap, with a T off the
cold feed.

Are both feeds at the same pressure?

>
> If so, can it be done DIY?
>
> If not, what would it cost me to have the new sink and mixer installed
> by a plumber? I need to go for the cheapest option.

That's probably easier to DIY than your suggested solution.

Check the cost of a new basin and tap - around £100 at the cheap end.

Plumber cost - maybe £200? Maybe £400? Get a quote.

[GB]

Ah, you got there first!

[John Rumm]

On 28/08/2023 19:46, Simon Ferrol wrote:

> The hot water in my bathroom sink is too hot. The sink is too small to
> accept a plastic bowl to do the mixing. Water temperature cannot be
> changed due to electric boiler having pre-programmed temperature.
>
> The taps are 40cm apart from each other. Sacrificing one tap, is it
> possible to replace one of the two taps with a mixer tap and bring the
> water from the other tap with a flexible pipe?

You could fit a monoblock mixer in one tap hole and blank off the other.
The tails to the taps are usually 8 or 10mm small bore flexi pipe.

> If so, can it be done DIY?

Of course.

> If not, what would it cost me to have the new sink and mixer installed
> by a plumber? I need to go for the cheapest option.

Have you considered just adding a thermostatic blending valve in the
pipework beneath the existing sink and taps? Then you can set whatever
limit you like on the hot water.


--
Cheers,

John.

/=================================================================\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\=================================================================/

[GB]

>
> Have you considered just adding a thermostatic blending valve in the
> pipework beneath the existing sink and taps? Then you can set whatever
> limit you like on the hot water.

I did ask above whether the two feeds are equal pressure. That's because
I couldn't find any blending valves that take unequal pressure. YMMV.

Simon, we are talking about these:
https://www.toolstation.com/made4trade-tmv2-tmv3-thermostatic-mixing-valve/p65850





>
>

[alan_m]

On 28/08/2023 21:34, John Rumm wrote:
> On 28/08/2023 19:46, Simon Ferrol wrote:
>> The hot water in my bathroom sink is too hot. The sink is too small to
>> accept a plastic bowl to do the mixing. Water temperature cannot be
>> changed due to electric boiler having pre-programmed temperature.
>>
>> The taps are 40cm apart from each other. Sacrificing one tap, is it
>> possible to replace one of the two taps with a mixer tap and bring the
>> water from the other tap with a flexible pipe?
>
> You could fit a monoblock mixer in one tap hole and blank off the other.
> The tails to the taps are usually 8 or 10mm small bore flexi pipe.

The hole for a conventional tap can be just slightly larger than 22mm

The hole required for a most/all monoblock mixer taps will have to be
32mm+ . The hole has to accommodate the two 10mm flexi pipes plus at
least one threaded rod.

Slightly off topic but related

I used the Split Klick centralising washer for the first time a few
weeks back - I wish I had discovered them much earlier as it saves a lot
of time when the hole in the sink is perhaps 3 or 4 mm oversize. They
are expensive (£2 each in Screwfix, £1.36+VAT at BES) but will centre
the tap without trying to hold the tap whilst attempting to tighten the
nut under the sink/basin. As delivered they fit 1/2 inch bsp basin taps
and if you cut out the inner recessed ring with a craft knife they can
be used with 3/4 inch bsp bath taps.
https://youtu.be/mavcUOrw0Vo

They also do centralising washers for monblock mixers in single and two
threaded rod variants

https://youtu.be/P5UME-df2As

https://www.bes.co.uk/catalogsearch/result/?q=split+klick


One other tip is to throw away the plastic backnuts that secure the tap
to the basin and use some brass versions
https://www.screwfix.com/p/flomasta-bsp-female-flanged-backnuts-1-2-x-2-pack/66268

I've found that on more than one occasion the plastic nuts are too soft
and when tightening up they get to a point and then jump back one
thread. Better to get the brass back nuts before you start the job :)



--
mailto : news {at} admac {dot} myzen {dot} co {dot} uk

[Colin Bignell]

He said cheap and a plug is way cheaper than a thermostatic mixer.

--
Colin Bignell

[Simon Ferrol]

I don't see this solution as very hygienic.

GB:

[Simon Ferrol]

No because I have no idea what it is. Is it something that mixes hot and
cold water before it reaches the tap? The two taps are 40cm apart.

John Rumm:

[Simon Ferrol]

Ah ok. Thanks. I still don't understand how it works.

GB:

[Simon Ferrol]

I'm going to look on Youtube.

Simon Ferrol:

[GB]

On 29/08/2023 10:02, Simon Ferrol wrote:
> No because I have no idea what it is. Is it something that mixes hot and
> cold water before it reaches the tap? The two taps are 40cm apart.

Yes it is exactly that. Several people here have suggested it. It
involves tee-ing into the hot and cold feeds to the basin, so you will
need to be able to turn everything off, and do some basic plumbing work.

[Andy Burns]

John Rumm wrote:

> Have you considered just adding a thermostatic blending valve in the
> pipework beneath the existing sink and taps?

If this is the same flat that Simon moved into recently, the landlord
may not approve of DIY plumbing?

[John Rumm]

On 29/08/2023 10:05, Simon Ferrol wrote:

> Ah ok. Thanks. I still don't understand how it works.

What a blending valve?

It has two inputs (hot and cold) and one output (hot). You set the
desired output temperature with the knob on the valve. If the incoming
hot water is higher than that, then it mixes in cold such that the hot
coming out is at your preferred temperature. This allows it to reduce
the temperature of stored hot water to a safe level at the point of use,
and also to eliminate fluctuations in temperature caused other
concurrent water demands in the house (within reason!)

[Andrew]

Is this a rental property though ?.

If its a housing association property then they should have
fitted a thermostatic mixing valve anyway to comply with
various building regs.

[Andrew]

My thought entirely. It its a housing association property then
there are building regs that relate to preventing hot water
exitting any tap from exceeding a certain temp, or is this
new builds only ?

[Brian Gaff]

I guess if you blocked the other hole up with a bung of some kind, but there
could be other solutions I suppose. Most taps in my house have semi flexible
connections due to the new basins and sinks having a different position for
their taps.
Be wary of those convoluted bend once pipes though, after 5 years one
sprang a pin hole and squirted water inside the bathroom vanity unit an in
your eye if you were unlucky.
The ones with a kind of braided look and a plastic outer seem much more
reliable.
Brian

--

--:
This newsgroup posting comes to you directly from...
The Sofa of Brian Gaff...
bri...@blueyonder.co.uk
Blind user, so no pictures please
Note this Signature is meaningless.!
"Simon Ferrol" <simon....@englandmail.com> wrote in message
news:uciq2m$1qnal$1...@dont-email.me...

[Harry Bloomfield Esq]

On 28/08/2023 19:46, Simon Ferrol wrote:

> If so, can it be done DIY?

You could blank one of the two tap positions off, and connect a
thermostatic mixer to both hot and cold, plus it's outlet to one tap.
You could then adjust that, to provide the perfect temperature in the
washbasin.

Alternatively, you could blank one tap position off, and perhaps fit a
mixer tap, if the remaining tap hole is large enough to accept a mixer,
and the mixer suites both the pressures of your hot and cold water
supplies - it may not....

An open vented system (tank in the loft, cylinder in airing cupboard)
would need a tap suited to low pressure.

Almost anything is DIY-able, it depends on your tools, skill and
experience.

[Colin Bignell]

On 29/08/2023 15:43, Harry Bloomfield Esq wrote:
> On 28/08/2023 19:46, Simon Ferrol wrote:
>> If so, can it be done DIY?
>
> You could blank one of the two tap positions off, and connect a
> thermostatic mixer to both hot and cold, plus it's outlet to one tap.
> You could then adjust that, to provide the perfect temperature in the
> washbasin.

In that case, I would leave the cold water tap as an alternative to the
thermostatically controlled hot water tap.

> Alternatively, you could blank one tap position off, and perhaps fit a
> mixer tap, if the remaining tap hole is large enough to accept a mixer,
> and the mixer suites both the pressures of your hot and cold water
> supplies - it may not....
>
> An open vented system (tank in the loft, cylinder in airing cupboard)
> would need a tap suited to low pressure.
>
> Almost anything is DIY-able, it depends on your tools, skill and
> experience.

--
Colin Bignell

[Robin]

On 28/08/2023 19:46, Simon Ferrol wrote:

You really need to talk to your landlord about this.

In the meantime you could use the plug to wash in a mix of hot and cold,
then rinse using cold to assuage your worries about hygiene.
--
Robin
reply-to address is (intended to be) valid

[Harry Bloomfield Esq]

On 29/08/2023 15:58, Colin Bignell wrote:
> In that case, I would leave the cold water tap as an alternative to the
> thermostatically controlled hot water tap.

Good point - handy for tooth brushing.

[Colin Bignell]

You also don't have to work out what to do about the spare hole.

--
Colin Bignell