Advice on Installing a new central heating system

HI,

I really could do with some advice on fitting a new central heating system. I have worked off old systems before and added new pipes, etc, but never attempted a whole new system.
I have just bought a new house, and there is no central heating in the place. I have decided to try and install the pipe-work and radiators myself, and then get a professional to fit a combi-boiler.
The only problem is where to find information about how the piping needs to be laid out, does each rooms pipe's go to the boiler, etc.
Furthermore, I am trying to decide on the type of pipes to use; some of my friends have recommended using plastic pipes instead of copper - as they are easier to install. However, I can't seem to find a cheap supplier, or a supplier at all. Also, I have read reports that some people's plastic pipes have been chewed through by mice - causing more damage.

I would really appreciate any help, advice, details of a cheap supplier.

Thanks

Hang your rads first

Lay some 22 mm copper pipe under where your boiler will be sited to act as your flow and return and run along the landing. Look at where your rads are and work out how you need to feed them. The aim should be to feed each rad by branching off in 15 mm to upstairs and down.

You can feed 2 rads off each branch if you wish but I believe flow will be better if off the 22.

Let us know how you get on.

Doing it from scratch wil take longer than you think, but it's very satisfying when it all works. Wickes do a free leaflet. Which publish a book, that covers heat calculations and pipe sizing and other aspects, but the copy I've got isn't fully up to date, maybe they've revised it. The copper development agency (Google) publish many helpful leaflets including pipe sizing. Lots of tips on this forum. Do your research thoroughly. I hope you enjoy it

The which book is extremely good.

http://www.amazon.co.uk/exec/obidos...8-3/ref=sr_8_xs_ap_i3_xgl/202-9666660-1478221

But it's out of print. I'd hunt around in bookshops or your local library.

On a practgical level, plastic out of site, copper in view. Main benefit of plastic is you can drill joists in centre of their hight up to 1/4 of the depth of the joist , but not down the middle of the room, in the bit close to supporting walls but not too close. ground floor sling plastic under joists lag with thick lagging same thickness as diameter of pipe, clip or strap to every joist (with builders band or twin and earth nailed through).

Use insterts in the plastic, use tectight fittings when going from copper to plastic otherwise hepworth or JG speedfit.

Make sure pipe is pushed right home into fittings, a smear of silicone grease assistes process.

Screwfix sell it. Buy the pipe with barrier in it.

Main drawback of plastic is gas ingress precipitating sludge formation. Mostly mitigated with barrier pipe but not as good a seal as soldered copper.

My old boss still insists on copper for the whole installation. But he's very much alone among professionals. I held out for a while but manager of trade place took me asside and said you're the only one not using plastic. Got the message and saved two days on a weeks work. Same costs.