We converted a five bed house in London for students and the plumber
put in a gas Vaillant turbomax plus 828 to serve a shower and a bath.
All the old pipe work from the old conventional system is still insitu
just blanked off. Frankly the combi is just poor; baths are just not
worth having and the shower flow is disturbed so much by washing
machines, dishwashers etc.I thought I could get away with it because we
all know students dont wash but this lot do....

I have read what you all say about combis but think that they are
useless for more than one old lady in a flat, I am afraid.

We now want to put in a an en suite shower room on the second floor,
exactly where the old airing cupboard/immersion heater was. The boiler
is on the ground floor in the kitchen and the existing bathroom is on
first floor.

I want to put a megaflow or similar unvented storage with an upgraded
new boiler.

The vaillant is nearly new and I wonder if some clever internal
rearrangement will turn it into a sealed system boiler or should I just
bite the bullet and buy a new proper one.

What do you reckon?