IS MY PLUMBER TALKING RUBBISH ( thermostatic shower valve)

[elvis9]

Hi , need advice. Recently purchased a Hudson Reed Kubix Triple Therom Shower Valve which runs of a min 0.1 bar (LP1) . The cold & hot inlet have a 22mm thread connection. The outlets to the shower head & Body Jets (x4) also have 22mm thread.
The plumber i am using has said its ok to run 15mm pipe from the Combi Boiler (which is less than 5m away) then use a 15mm - 22mm connector to link to shower valve. And do the same for the outlet for shower head & jets 22mm reducer to 15mm.

A) Will i lose shower pressure by doing this?

B) Is it best to run 22mm to valve and 22mm from valve to shower head & jets - shower head has a 22mm thread) OR 22mm to valve then 15mm to shower head & body jets.?

your thoughts would be good

 

[SimonG]

I would do it in 15mm. Your limitation is your combi, incoming MCW to combi will only be 15mm. If you had header tanks and DHW with pump then I would do it in 22mm.

imho

 

[Jimbob]

Your plumber is right, running in 22 from a combi is pointless.

I think you owe him an apology and need to get him some nice biscuits next time he visits.

 

[pedroski]

no he's talking sense. i'm not sure about this 0.01 bar minimum surely you mean 1 bar.. any way you'll have way more than that with a decent combi thats not knackered. i sometimes come across customers such as yourself. trust him and tell him you posted this. see what he says

 

[Billy Bob Bob]

i bet your plumber would love you if he/she knew you were on here whineing

 

[pedroski]

lets be right you weighed in with IS MY PLUMBER TALKING RUBBISH ...... that says a lot about you.....give him a break it would have been much more appropriate to have been polite. then perhaps you would have got a better response on here.

 

[elvis9]

thanks for the response guys, didnt mean to take the negative tone in the title i have had 2 plumbers look at the job and its been a 50/50 split on what size pipe is best to use so needed to clear it up.
Furthermore any ideas of the best material pipe to use in concrete screed to feed
the bathroom for hot and cold... again i have had conflicting responses ( copper wrapped in denso tape/ grey grab ring push fit / mdpe / copper in ducting ?

thankyou

 

[SimonG]

Personally I would use speedfit and I have some old Uponor pipe sleeving that I would put it in. But thats just me.

I like the sleeving because if the pipe has to be replaced, for whatever reason, it can be slid back through the sleeving without ripping the floor to bits.

 

[Billy Bob Bob]

thank you for being honest,can understand your having conflicting views in regards what to use all is ok if installed correctly plastic has the advantage of not corroding but copper is just as good if denso taped

 

[elvis9]

thanks gasman & simon G , i have reservations about white push fit plastic (john guest) because i recently lost the whole of my downstairs because of it. It was buried under the limestone tiles feeding the two bathrooms and two bedrooms all of which had to be taken up along with the underfloor heating. It was caused by a push fit 'T' underground feeding hot water to the shower. luckliy it was covered by the insurance but its been 4 months now and the plumbers appointed by the insurance company are finally starting 2mor , but they have suggested using john guest push fit again??
Am hoping there is a better product out there to use.

 

[Billy Bob Bob]

there is copper but also polypipe grey (may now be white) compression fittings and aluminium inserts do not come apart

 

[smillsey]

i still cant bring myself to go with plastic,

im an idiot for not though

 

[joerollestone]

when using pushfit fittings in concrete floor u need to leave a expansion gap around every joint else they will just pull out eventualy!

 

[Dannypipe]

I try to avoid putting joints in a concrete floor, but where unavoidable, I'll either use copper and solder the joints (all wrapped in Denso after testing) - or use Poly Plumb which can self release like JG Speedfit.

 

[kimbo]

Nothing wrong with speedfit if assembled correctly there have been more blow offs on hep2o than speedfit thats why they have redisgned it. I have been using speedfit for 11 years and not one fitting has failed. I believe they have been going the longest and everyone has copied them.

 

[Gray0689]

Pushfit fittings are not designed and have no warranty if used under concrete floors

 

[elvis9]

Thanks for the input guys. I have decided with the plumber to go with copper wrapped in tape. Am trying to get him to use Denso tape , is Duck Tape just as good because thats what he plans on using.

 

[Bartdude]

Uponor MLCP is the best. It's more expensive but worth it. There's no comparison between their crimping system and a push fit fitting. I know of too many instances where push fit fittings have failed and caused damage. These systems have their place but I wouldn't use it for a whole system.

 

[aceservicing]

If you can afford it run a new integral mains water supply just for boiler . Supplys to shower to have non return valves , respect your plumber . Your boiler should be
Min 12.5 LTS domesit hotwater flow rate with 35deg temp rise .. I have seen many showers with bad flow rates or they complain tap open or someone flushing toilet they get burned in shower or freezing cold .

 

[Barwil]

Under almost all circumstances, 15mm feeds hot and cold is perfectly adequate to the valve. The only time (which does not apply in your case) is where the valve is fitted to a low pressure system. You say the valve is rated to work at 0.1bar or 1m head which is extreemly low pressure so in order for the valve to function correctly large bore pipework is required to supply the valve with sufficient water. The valve may be fitted with 22mm connections for this purpose but once the pressure exceeds 0.5bar the use of 22mm is no longer required. Now the size of the outlet becomes important to maximise the flow through the valve. In days gone by, and here at Barber Wilsons it is still the case, mixer valves step up one size on the outlet, so for 1/2" feeds the outlet will be 3/4", 3/4" feed, 1" outlet. If you fail to do this then you fail to realise the maximum achieveable flow rate from the two supplies once they are mixed. One final point concerning your combi boiler. This will have a maximum flow rate for a given temperature. All thermostatic valves require a minimum of 50 deg C hot water to function correctly. Correct selection of combi-boiler is critical to achieve the desired showering function as I suspect that you will wish to utilise the body jets at the same time as the overhead and possibly overreach the capability of the boiler to produce sufficient hot water leading to disappointment of the user.

 

[stevetheplumber]

in concrete floors id use plastic pipe but only if its one length with no joins

 

[aceservicing]

Sounds good 2 me