I replaced an old essential shower in my house for a Creda 550c 9.5kw shower. After I installed I wasn't happy with the force of the shower so I changed it for the 10.4kw version and it improved slightly but not much. Both of these new units are way less powerful than these new units. I don't get a low pressure warning either. When the flow is cold it is very powerful but as soon as you increase the temp it is pathetic. Any ideas??