On 2007-04-29 09:14:22 +0100, said:


Thanks for that,will I get a powerful shower with a combi?

At some times of the year, yes.

However, in the winter, the mains water is at 5 - 8 degrees. Shower
water temperature is 40 degrees. Combis are rated in terms of flow
rate for a 35 degree temperature rise. Therefore, the flow rate at
the shower will be that of the combi.

A 30kW combi will manage about 12 litres/min under these circumstances.
A worthwhile shower is at 15lpm and above, so a 38kW combi is really
needed to achieve that.

All of this assumes that the mains supply can deliver this flow rate.