Thermostatic Mixer Shower - Bar Pressure and Water Flow Question

Your boiler will probably work of mains water pressure which should be fine, the cold supply will be from either a tank in the loft (UK style pumbing) or mains water pressure.
If it's mains water pressure it should be ok.
If it's a tank in the loft you need to check how high it is, the higher the better, 0.1bar is about 3.2 foot of height*, so the tank needs to be at least 3.2 foot above the shower outlet.
I raised the cold tank in my loft by about 2 feet to improve the mixer shower water flow.

You can always measure the flow with a graduated jug and a watch.
Hope this helps.
Del

* Acording to the bar to feet of water conversion I just googled (I thought it was nearer 4.2feet myself.... but you can google it yourself.

Many thanks Del,

Yes, both hot and cold are based on mains water pressure

Del has it dead right.

The best is when both hot and cold are supplied direct from mains water, with NO header tanks in between.

If a header tank system is used, then you need to include a water pump in that side with a pressure regulator to match (close is good enough) the cold water supply, or BOTH hot and cold must be suppled from the same header tank.

If both from the same header tank then install the widest bore tubing that you can get, I used 22mm many years ago in my house in the UK and the flow was adequate/OK, but not overdone (still better than most of my UK friends house water systems!)......even bigger bore pipes may have improved it even more....never tried that though.....would have taken too long for the hot to get through with a large waste of water.....

....so go with the flow....in a low pressure system!

Now I am in Germany and we have (as far as I am aware anyway) ONLY mains pressure systems, with no header tanks for both Hot and cold water and heating systems.....usually between 4 and 6 bar (1 Bar x 14.5 = aprox pounds per square inch)

With regard to showering and even health reason (no chance for bacteria to breed in a tank and get breathed in when showering - Legionaire's disease for example), I find it much much better......I like a shower with POWER!!!

Basically,that's all you can buy now and they are all made to operate from about 12psi to 80 psi. Federal Gov in your shower...

Del is correct.

Going further, assuming that you shower around 41.5C, and your cold water is around 6C, and you have a new flow-limiting shower head (5.75 to 6.5 l/min), your hot water flow (50 C) will be between 4.65 and 5.25 l/min (well above your heater's minimum) and- as stated earlier- your minimum total flow will be 5.75 l/min so all should be well.

Go on and help save the world.

many thanks to all who replied to my original question, it's put my mind at ease and I will go ahead with the shower purchase

Cheers,

Keith U.K.