Hi All,

I am about to embark on the DIY equivalent of my first bungee jump!

I have a normal 3-bed terraced house in the london area and have the
normal
"back boiler", hot water cylinder, loft sited water tank, and loft
sited c/h tank. I want to replace all this with a combi boiler.

My question has three parts:
1. I have 7 radiators but may want to add more in the future (in case
we extend so possibly 4 more). I have one bathroom and 1 kitchen. What
size boiler would be recommended?

2. I would like to site the boiler either in the loft or the bathroom.
The old airing cupboard which currently houses the hot water cylinder,
i will be making part of the bathroom. So I guess putting the boiler
into the bathroom would make sense. Is this legal? I know combis use a
sealed flue system (i have a basic understanding) but i would really
appreciate some advice on this

3. If I was to run the gas piping (22mm copper?) from downstairs to
upstairs can it be sunk into the wall? Where is the places to avoid
running gas piping?

I have a mech/elec background and know a little about water and gas
pipework (i.e. to test for leaks with soapy water) but thats about it.
I would really like to do as much of the work myself as its cheaper
and I will be taking my time to do a good job: I have to live here

Thanks in advance for you help

Markie