So our water supply comes in through the cellar and then splits in two to feed the kitchen/boiler and bathroom respectively. We just had the plumbers in to re-site the pipework before we do a cellar conversion. The plumbers have done a great job but one decision makes me wonder.
The have used 22mm from the main supply to run the 15 feet across the basement and then reduced down to 15mm for about two feet before splitting onto the two existing 15mm pipes that go off to the kitchen and bathroom. Any idea why they would introduce this short section of 15mm rather than taking the two feeds directly from the 22mm? My simple mind thinks splitting a 22mm feed is better for flow than splitting a 15mm pipe especially if both pipes are feeding simultaneous demand.
I had previously mentioned to the plumber that flow to the bathroom gets hit whenever, say, the dishwasher goes on and was hoping to reduce this impact if at all possible. I asked the plumber about this thinking there was a technical/practical reason but got a "it wont effect anything" response. Thoughts ?
Length of each section of pipe is also important as well as the diameter.
Best ask the question another way. I'm not good at this. Ask for the problem you have with the shower(?) what changes are needed to the pipework and hot water systems to improve it?
Silly question: Is your hot water pressurised? I.e. no header tank?
If so then changing to 22mm all the way to the pressurised cylinder might help. Accumulators might be another possibility if you have the space (I don't know much about them though so leave that thought to others)
If you don't get any answers from your basement engineers, then best ask your central heating / hot water engineers, or find a good one if you don't yet have.
May also need some tests on the incoming supply pressure and flow.
Thanks both for the response. I am really curious about the consequences of the plumber's choice to reduce the pipework to 15mm before the tees as this seems counter-intuitive but I'm no fluid dynamics expert! I know it wasnt just running out of 22mm as they went on to replace the gas pipes in 22mm. Maybe he had run out of 22mm/15mm tees ? Regardless, would you ask them to redo this short section in 22mm or just accept it and move on?
I gave the demand example more to emphasise why I was curious about the pipework above. The plumber suggests the demand issue is ultimately down to a lead pipe mains feed and would be significantly improved by going "lead-free" and getting a new "fatter" supply line. Given that I will probably do this at some point in the future then the above point becomes more relevant I think.
Thanks both for the response. I am really curious about the consequences of the plumber's choice to reduce the pipework to 15mm before the tees as this seems counter-intuitive but I'm no fluid dynamics expert! I know it wasnt just running out of 22mm as they went on to replace the gas pipes in 22mm. Maybe he had run out of 22mm/15mm tees ? Regardless, would you ask them to redo this short section in 22mm or just accept it and move on?
I gave the demand example more to emphasise why I was curious about the pipework above. The plumber suggests the demand issue is ultimately down to a lead pipe mains feed and would be significantly improved by going "lead-free" and getting a new "fatter" supply line. Given that I will probably do this at some point in the future then the above point becomes more relevant I think.
Yeah, I dont want to push too hard on the plumber unless there is a valid raison as he has put in a ton of hours and gone above and beyond in accommodating us. To a layman the quality looks good just a question about this small part of the work. So basically, trying to judge whether we enter round two of conversation.
In terms of accessibility, all of the Gas and CH pipework throughout is accessible as is the majority of Mains Water and DHW. Unfortunately the last few yard of the Mains Water & DHW (between kitchen sink and boiler) is under the concrete kitchen floor. Having said that, the route that the CH/Gas takes to the boiler is accessible and could accommodate additional pipes if beneficial. So yes I could get 22mm pipes to the boiler but note that the Vaillant turboMAX 828-2-E has 15mm water fittings.
The incoming supply to the house could be changed taking advantage of Thames Water "lead-free" scheme and nothing problematic here other the cost of trenching to the house and feeding pipe under the suspended floor. Not something I am planning to do right now but maybe next year if my suspicious that this is the main constraint on flow is true?
A few pictures below showing the new pipework as it enters at the front of the house, runs through the cellar to the airing cupboard and then tees onto the legacy water pipes. Picture 4 is the main one at question. The last picture of the boiler shows that the Water/DHW comes up from under the concrete floor whereas the CH and Gas can be accessed behind the kitchen cabinets.
Thanks Scott, appreciate the re-assurance. Knowing that I was thinking about upgrading the lead main, is that how you would have plumbed that junction ? Just curious now as I've settled up with the plumbers and written a very positive review of their work.
Reply to Plumbers just finished up, did they do it right ? in the USA area at PlumbersForums.net
Hi, basic question, any insight much appreciated.
Looking to have an outdoor tap in my front porch fed from 15mm pex coming up from suspended floor. Pic 1 is inside porch, pex temporarily clipped to give an idea of pipe placement (ignore shoddy blockwork of booted cowboy builder!), Pic 2 is...
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