Flow problems

[Nafta]

Have combi boiler feeding thermostatic shower and have a problems with the flow. It starts off good and then it dies. Manufacturer says we do not have enough flow and council heating enngineers says the out let from the boiler is 22ml going into a 15ml fitting for the shower so it is to be expected and there is nothing we can do about it. Is this correct? If it is, will putting an extra large shower head give us the feel for flow we want?
The shower is a manila cascade thermostatic shower.
Thanks a lot!!

 

[Puddle]

Actually the opposite,if you put a smaller shower head on with a smaller flow rate this with improve the pressure through head
You should still be able to find a good shower head with vari flow and with a lower flow rate to meet your needs

It would be good to get a variable shower head so you can change settings between peak and off peak mains usage,as in the day during low peak you will probably turn to a better flow

 

[tackleburger]

I think there is a problem such as debri somewhere in the pipework. I have never had a bar mixer that has been a problem on a combi.