New Central heating system

[Dharm1]

HELP!!!
I have just purchased a house which had storage heater that have been taken out, as I would like to have a new central heating system installed, so I have a few questions.
First the background,
I would like to use a combi boiler Vaillant ecotec plus 837 ( because of the water follow rate it will give me).
6 rads downstairs and 4 rads upstairs, average size of rooms is 3 x 2.5 meter.
Bathroom upstairs and shower room downstairs.
First question do I use copper of plastic pipes ?
I know that copper in material cost is cheaper but in installation is more expensive.
With plastic the pipe is relatively OK in price its the fittings that increase the cost and installation is much more quicker.
I will use a two pipe system but what would be the best way to route the pipes! 22, or 15mm throughout?
Would there be a problem with flushing the system with plastic pipes?
Please note to save cost I am planing to lay the pipes myself to the rads ( I feel I am a competent D.I.Y'er), but will get a professional to install the boiler and connect to central heating pipe work!
I would very much appreciate any advice/help you can give me!
Thanks

 

[JoeMar]

hi

i have recently completed a smillar project as the one you are about to start only I had a 937 installed (in the loft).

The previous system was a one pipe system so i had to run all new pipe work. Everything is done in copper, 22mm for the main run then branch off in 15mm to the radiators.

You can use plastic but the 1st metre from the boiler will need to be in copper...

You will almost definitely need to upgrade the gas supply - something to bear in mind when considering the position of the new boiler.

Remember drain offs at low points and also invest in a magnaclean (or simillar).

Good luck...