I was really referring to the statement from the supplier.
If the flow is being measured at the end of the 32mm service pipe, the pressure was 2.8 bar and the flow only 25lpm, it suggests that something else is wrong.
.andy
To email, substitute .nospam with .gl
Non return valves? They slow it down a lot.
It is compulsory to have one on an outside tap.
High flow ish. Its on 22mm copper feeds. System is unvented.
One shower at a time and its totally fabulous. Skin ripped off back etc. Two showers together is only as good as yer typical large combi.
Pipework is mixture of 22mm and 15mm.
True, but utterly irrelevant.
I did the test at 8.30 this morning.
My main stopcock in the house is a 32mm bore quarter-turn valve*. I couldn't take the water directly from the stopcock outlet. It had to first go through a straight 2m run of 15mm pipe before I could discharge it into a bucket. (*Note: There is also a 25mm quarter-turn stopcock at the water meter end of the supply pipe.)
I comfortably filled two 15 litre buckets in one minute.
Your problems appear over. 30 litres/min is good enough. This should be fine for 2 showers and one bath on a mains pressure system. Go for:
View two combi boilers. One doing one zone of space heating (upstairs) the other doing another (downstairs). Each boiler will have a programmer/stat for each zone, preferably a Honeywell CM67, or equiv. Combine the DHW outlets just before the bath using non-return valves and a small shock arrestor expansion vessel, as per Worcester-Bosch Tech dept. It will fill a bath pronto and give good power showers for two showers.
With combi's the most important figure is the flowrate. 11 litres/min is fine for showes and the odd slow filling bath. Here is a recent post of mine...
For an even better flow rate and cheap too for what you get, assess using two Worcester-Bosch Junior combi's.
For high flowrates it is cost effective to use two Juniors and combine the DHW outlets. Worcester-Bosch will supply a drawing on how to do it, or ask me here. Two Juniors are available for around £1000 to £1100 depending on what sized units you buy. They have 24 and 28 kW models, you could one 24kW and one 28 kW. That is cheaper than the Worcester HighFlow 18 litres/min floor mounted combi and can deliver about 21.5 litres/min @ 35 degree temp rise and never run out of hot water. The highest flowrates of any infinitely continuous combi is 22 litres/min @ 30 litre/min temp rise, which is the ECO-Hometec which costs near £2K.
Have one combi do the downstairs heating on its own programmer/timer (Honeywell CM67 or equiv) and one do upstairs. No complex and space consuming zone valves used. Natural zoning, so you don't have to heat upstairs when you are not up there saving fuel. The running cost will be approx the same as a condensing boiler heating the whole house. No external zone valves either, and simple wiring up too. The Juniors are simple and don't even have internal 3-way valves.
If having two showers, have the shower split between the combi's to reduce influence from one to the other.
Also if one goes down you will have another combi to give some heat in the house and DHW too. Combine the outlets for the DHW bath pipes and all the baths you want very quickly and no waiting. Best have the showers on separate combi's.
Do not exceed the gas meter flowrate of 212 cu foot per hour. To calulate, e.g., a boiler is 100,000 BTU/hr "input". Divide by 1000 giving 100 cu foot per hour. Add up all the appliances.
The Juniors are not condensing combi's, yet overall heating costs will be equivalent to one condensing boiler as the upstairs will not be heated most of the time.
A win, win, situation.
Its advantages are:
- cheap to install.
- quick to install.
- space saving (releases an airing cupboard). Both can go in the loft, or at the back of the existing airing cupboard.
- never without heat in the house as two boioers are used.
- high flowrates (will do two showers and fill a bath in few minutes),
- No waiting for a cylinder to re-heat
- Natural zoning, one does upstairs and one does down
- hardly any electrical control work (running a wire to a programmers/stat and power to each,
- simple no brainer installation,
- minimal components used.
- less piping used
- cheap to run overall as upstairs would be off most of the time
- etc.
OK. That changes the picture completely. You can go for the planned pressurised storage system and get very good results.
Two things.
Make sure that you go for a large enough HW cylinder - I would suggest a 150litre one or more. I have a 200 litre HW cylinder for similar requirements to yours and it does the job admirably, even in coldest weather.
The other thing is to plan the internal pipe sizes carefully.
If the water softener is a long way from the stop tap then perhaps a
28mm pipe to it, but certainly 22mm.For the run from there to the HW cylinder, 22mm.
If there is a run for cold water to several bathroom taps make that
22mm as well.You can then drop down to smaller sizes closer to the taps or fit flow restrictors.
The trick becomes to size and arrange things to provide reasonable flow balancing.
.andy
To email, substitute .nospam with .gl
Check the flow rate again at 6.30pm on a weekday. IME a 2:1 variation can be experienced.
Regards Capitol
I second this advice in every detail. Essentially its what I have, and it works well.
The problem is that a water softener is a _huge_ restriction on the flow and with any form of direct HW systems it will be the bottle neck.
It does not make a problem elsewhere.
Best have a phosphor in-line descaler.
Is this your personal experience?
The Kinetico 2020c High Flow Softener has a service flow rate of 33 lpm and a peak flow rate of 51 lpm. Providing that I use a suitably large pipe diameter, is this really going to appreciably slow down my 30 lpm supply?
There are some things that you can do to mitigate this:
- Look for the highest flow model that makes sense. This does not necessarily mean picking one that is suitable for a larger number of people in the house - that is more of an issue with single chamber machines which regenerate at night, and those for more people simply have a larger resin chamber to be able to deliver a greater volume of water over a day. You can get commercial models with higher flow, but they get rapidly expensive.. If you look at specs. you can ask the suppliers for their flow/pressure graphs (for the system, not just the valve) and pick from these. Some machines have 1" rather than 3/4" fittings which can help.
- You can get wide bore hoses. Often, the ones normally supplied have as little as 12mm bore, so it's useful to get larger ones. I replaced mine on a Kinetico a while ago and it did help somewhat.
- The stop valves supplied with the machines are sometimes not full bore. You can use 22mm or as discussed before, 28mm quarter turn lever ball valves.
- You have to have a double check valve with a water softener, and these do tend to restrict flow. You can fit a larger one than that implied by the pipe - e.g. a 28mm one on a 22mm pipe.
.andy
To email, substitute .nospam with .gl
Yes this is my diret experience at one site. It would clearly not have been had they used the Kinetico High Flow unit which I expect is a tad more pricy than a typical unit.
As to whether this is best or not will depend on the reason the OP wishes to threat the water. Adding phosphates is not the same as exchanging ions and that's not the same as removing ions.
This is a borderline mains pressure system. Anything that may restrict flow/pressure should be avoided. Most people only want to descale. A phosphor canister does that well and does not restrict flow.
No. just *A* bottle neck.
Mine is totally capable if one shower at insane flows, and two showers at normal flows.
That is simply not true.
Most people want to eliminate nasty scums from their baths, and scale deposits as well.
A
It is true.
HomeOwnersHub website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.