Just seen on the news that Thames Water is going to reduce
the water pressure in London until they can find the money
to replace the leaking water mains. Potential combi owners
(and current combi owners) might want to bear this in mind.

One of the London boroughs has had to spend £1M so far on
providing booster pumps so water will reach the tops of their
taller buildings, and as the pressure drops spread, they are
expecting to spend the same again. They have complained to
OFFWAT that Thames Water is allowed to drop the pressure
but not responsible for picking up the bill. Some taller
houses will apparently also need booster pumps.

--
Andrew Gabriel