I have just moved into a property and experiencing difficulties with the shower. I have a Ravenheat Combi Boiler (capable of up to 10mb of pressure?), and a new Mira shower put in after I moved as the old shower was dreadful (Mira advised this is the best shower for the boiler).

When you turn the shower on, it takes a few minutes for the hot water to come through, it is fine for about 2-3 minutes then the water starts to pulsate (there is no banging, but the boiler clicks on and off continually), after another 2-3 minutes the water then goes cold.

There is poor pressure with the hot water (you have to turn on the tap very gently) to get hot water, which then dies down, and you have to turn the tap slightly to get more etc.

Can anyone help with this so we can have a decent shower. Please

Thanks

Callum