best practise on installing a central heating system and new pipe work.

[noel6072]

Hello folks, I am in the process of replacing my old oil outdoor boiler with a new outdoor condenser boiler. I have got a couple of plumbers around and they have all stated the pipework will need replacing as the house was all done with 1/2" piping and none of the radiators have 3/4" piping going to them. The pipework is easily accessible as the bungalow has trunking in situe. The house never warmed up sufficiently especially the last 2 bedrooms. The plumber I have chosen has said that he will be connecting up 3/4" copper piping around the house and leaving the bottom two bedrooms with 1/2" piping. This will mean the 3/4" copper piping will be connected up to plastic 1/2 piping.

I will be adding 5 new radiators in the house and the plumber has said he will chase the copper pipework in the concrete floor as I do not want any more trunking around the house. The bedrooms will not have pipework chased as they have new carpets however the rest of the bungalow will have the pipework chased.

I have a few questions from you knowledgeable people, firstly can 1/2" plastic piping be connected to 3/4" copper piping? Is chasing 3/4" copper piping best practise when one does not want more trunking around the house? The plumber stated on the last day of installing the condenser boiler he will be getting someone to commission it, is this normally done by someone who specialises in it or should the plumber be able to do it? and lastly can heating controls be added on by an electrician after the system is running as I only have the old dial clock from my last boiler. Many thanks in advance.

 

[Mike Jackson]

It's normal practice to run the main CH flow and return in 22mm and tee off in 15mm to the radiators. As a rule of thumb you can normally get away with two large radiators or three small ones on a 15mm pipe.

If you don't want pipework showing then chasing it is going to be the only option.

It's quite normal for people to get a specialist in to commission an oil boiler.

When a new boiler is installed the controls will need to be upgraded to meet the building regulations. This can be done by an electrically competent heating engineer or an electrician.

 

[noel6072]

Great thanks for that info Mike

 

[lame plumber]

by trunking I presume you dont want any drops on view or having to bow pipes in. Personally I'd advise a bungalow owner to run the system in the roofspace and have the pipe drops hidden behind their curtains or hidden behind doors etc. Certainly cheaper to do than carving up your concrete skim and in some cases blowing through your damp course and all the resultant issues that can cause.

Re using a plumber not qualified in oil to install a boiler for you, I regularly go to oil boilers installed by a gas plumber and have to sort out cock ups, ie running the feed pipes into the boiler casing in copper then connecting flexies on, as the installer has conacted a long flexi down the side of the boiler, then pushed it up against the wall, such that the servicing guy cant even reach the connector to replace the flexi when needed. Or no fire valves, no isolator on the oil line at the boiler, soldered joints on oil lines and it just goes on. Why would you use someone who isnt trained to install something that costs you thousands? I know, coz its saved a few quid at the start just because you can doesnt mean its right, end of rant

 

[noel6072]

Interesting concept of running the central heating system through the attic, just a couple of questions on that, does the twin coil cylinder have to be also put in the attic? Does the water tank have to raised up above the cylinder? The main issue I have with running it through the attic is having pipes going to 10 radiators down each of the walls and looking unsightly I know the routing up of the floor is not the best option however to avoid having trunking in the main living areas it might be the option for my system as I would not like having pipes running down behind the curtains as currently have new blinds installed etc on the windows, as I will be more or else completely redoing the plumbing system for the oil boiler the attic system does sound interesting. Many thanks

 

[lame plumber]

get in some more quotes, you need specific help here to get things right, if your only thinking about this and youve already started , all your extras will cost a large fortune