teeing off main cold water supply from HE condensing boiler

[cono]

Hi

I wish to install an outside tap in the back garden. The easiest method I think would be to take it from the mains cold water supply to the boiler which is in a airing cupboard upstairs, through the ceiling, across the loft and down the back of the house. What pipe in the loft would be best barrier or copper? This is a Potterton HE boiler with integral water cylinder. There is a combination valve which has a stop valve incorporated. At the top of this you can tee off to provide a balanced cold feed to a shower. The supply going into this is 22mm and states DHW (not sure what this means) Mains cold Inlet and cold feed to kitchen tap, it is here that I am considering teeing off from using a 22mm to 15mm reducing tee. However I am not sure if this is ok. All of the pipework is a matt mottled silver not copper. Advice greatly appreciated.

Regards

Cono

 

[fitz1]

wheres your kitchen or bathroom situated in regards to your back garden.

 

[cono]

Hi Fizz1

The kitchen is at the front of the house (terraced), the bathroom upstairs next to the airing cupboard, position of pipework would make it difficult to take a supply from there. I have no intention of touching the gas supply as am aware of the danger. I have a schematic of the boiler which show clearly the various pipes and their function.

Regards
Cono

 

[dextrous]

I see nothing wrong with teeing in at this position. Personally, I prefer copper, but barrier will be easier to install - ensure you fit a double check valve, an isolation valve, and a drainoff valve on this new run.

 

[cono]

Hi Dextrous

Many thanks for the advice. Hope you don't mind if I ask some supplementary questions. The pipework as already mentioned is matt silver and has a rough mottled surface. Would this affect the joins/seals if I use compression or pushfit coppper? The combination valve has a facility whereby you can take a balanced cold feed to a shower. To use this facility would be the easiest option as I would not have to cut into the pipe, but if I do this would I lose cold water mains pressure to the outside tap? Is it normal that all the pipework is not copper in modern systems? ie does it come as a complete boiler package as all the pipework to and around the boiler is in this mottled silver colour, in this case the boiler is a potterton HE. Finally if I decide to use barrier pipe in the loft (as you say it would be easier) can you advise on the best make/quality?

Regards

Cono