It's a balance; from experience I know when I hit a subject with an all encompassing thread I often lose half of what I'm after, potential commentators switch off and I start being very military again with numbered lists and unfriendly looking re-direction. The mains I had was a 32mm MDPE >> Elbow to 32mm MDPE sticking up out the floor >> 25mm MDPE to 25mm/15mm brass stop tap >> 3" of 15 mm copper to push fit plastic. It would be one unbroken run from the stop cock at entry to the above floor T to the UVC and Cold supply. So I have a 24kW combi, with a 22mm supply pipe from the road (length 10 metres or so), until up close to the boiler.

32mm MDPE to 22mm copper - General Plumbing Going from 32mm MDPE to 22mm copper - General Plumbing

water supply , not sure why you'd need 28mm but makes sense not to starve/reduce potential flow to the combi DHW cold feed as djh says , to other take offs .To view the purposes they believe they have legitimate interest for, or to object to this data processing use the vendor list link below. Was he aware you were using a main pressure DHW combi , I presume he was referring to pipe sizing for a gravity fed/main presuure HW tank of similar.

FtD BRASS Compression STOPCOCK DZR 32mm MDPE x 32mm MDPE FtD BRASS Compression STOPCOCK DZR 32mm MDPE x 32mm MDPE

If you would like to change your settings or withdraw consent at any time, the link to do so is in our privacy policy accessible from our home page. I've kind of got a bee in my bonnet now (thanks to you guys :p) about doing what I can to reduce pressure/flow variations when multiple outlets are open - it's one real bugbear in my current wee flat - the minute one thing comes on (like the washing machine), the hot water taps or shower immediately drop in pressure.Compatible with both commercial and domestic properties, these useful valves are available in a wide range of sizes and materials. It is worth running large pipes to supply the combi with cold water, since that doesn't contribute to wasted hot water, and also other things such as the kitchen cold tap, toilets etc. Our rising main and stopcock in our old house is 15mm, and we have mains pressure hot and cold systems fed from it.

STOPCOCK 32X28 | Wolseley PRESTEX PL59A GUNMETAL STOPCOCK 32X28 | Wolseley

Some of our partners may process your data as a part of their legitimate business interest without asking for consent. PlumbNation is a trading name of Online Home Retail Ltd (company number 03852312) registered in England. I think we'll then change to copper (not sure what size yet, probably determined by what kind of meter and softener we can get), then a drain off valve, then the meter.I think I may be being a bit thick, but our incoming supply is 32mm, which I'm going to run right up to the plant room and tee off to the UVC and to the cold water manifold and fit a reducer to each. Cost wise the difference is negligible - was planning getting the pipe in the morning and running it through tomorrow whilst the replacement window is being fitted.