stupid question - standard pipe size bath/shower mixer?

[AlF2008]

Bit of a daft question.

We have ordered a wall mounted Crosswater thermostatic bath/shower mixer for our new bathroom but the one thing not specified on the tech diagram is the size of the input pipes. I know most, if not all, showers tend to be on 15mm pipes but bath taps tend to have 22mm connections. Now as this is a combined tap and shower mixer I'm not sure what to expect. It doesn't really matter but there are 15mm there at the moment from the old shower mixer so that would be more convenient.

I've sent a query to Crosswater about it but haven't got a reply yet.


this is the tech drawing:

http://www.crosswater.co.uk/pdf/Dimension/EV1211EC.pdf

I suspect it will be 15mm but wondered if anyone can offer any advice?
From the drawing I would also guess its a 15mm (provided its drawn to scale)

Can anyone offer advice (other than wait or phone crosswater )

 

[seco services]

i would say they are 1/2" bsp.
does it say anything about min pressure the mixer needs to work ?

 

[AlF2008]

Thanks for that. Wasn't thinking in terms of tap connector sizes....

Its a got a min operating pressure of 1bar.

 

[seco services]

i'd say 1/2" bsp - 15mm pipe.

 

[AlF2008]

Thanks again. I was hoping to use the existing pipes although I plan on addition isolation valves to them first as I've already had one plumbing near disaster this week

 

[seco services]

what type of system are you running the mixer from ie combi etc?

 

[AlF2008]

It will be a combi system hopefully later this year.
Currently its a conventional back boiler with tanks. I realise that this will not provide the required pressure so there is a backup plan or using the existing mixer until the heating system is changed.

 

[seco services]

that will be fine as you say the 1 bar mixer won't be any good on your system now.

 

[AlF2008]

Any idea what will happen if it doesn't have enough pressure? Will it simply not operate at all or just give poor flow etc?

I'd like to avoid having to change it at some point in the future but I suspect there is no way round it.

 

[seco services]

the shower will just be a waste of time and the flow from the taps will take for ever to fill a bath

 

[AlF2008]

Thats what I suspected. Will put the original back on and then worry about changing it over once the CH has been upgraded.

Thanks again for all the replies and info