Mains Driven Water System

[Jeff Gaines]

My HW is provided via a loft tank to a copper cylinder with 2 x immersion heaters, 1 is Economy 7 driven (bottom of cylinder) the other normal price electricity (top of cylinder).

The cylinder is bare with a loose cover so I want it replaced with a foamed cylinder.

The plumber has suggested I scrap the loft tank and have a mains pressure cylinder so all supplies will be at mains pressure.

Are there any things to watch out for, e.g. existing fittings/connectors put under mains pressure showing up weaknesses etc?

Is is possible to have a water softener with this set up (there is space next to the cylinder and it would be after the kitchen sink tap)? I won't say the water is hard here but sometimes it comes out of the taps in lumps!

[Dave Liquorice]

Is there actually much to be gained? You are not limitted to just a single loose cover and you could wrap space blanket loft insulation around it as well. Or build a a box around it and fill all the space with insulation.

Quite a possibility I would have though but do you want mains pressure everywhere? Personally I like the water to stay in the basin/sink when I turn a tap on not hit the bottom and bouce out or shoot around the rounded shape and out. B-)

[Tabby]

far less work and cost than a new cylinder!

Perhaps the plumber could make a list of other unnecessary works he could do for you too, at your cost of course.

NT

[The Natural Philosopher]

Good idead if your mains supply is good. Most are.

Its not that huge a pressure. really if there are issues you simply address them as they arise. Bt soldered joints will be no problem, and if compression are, generally they can be tightened or in the limit replaced.

I have such. It reduces the overall flow rate somewhat. Take the kitchen and an garden taps off the main incoming, then feed everything else via the softener, including the fillers for the actual pressurised heating primary circuits.

You MAY need to get different shower heads and possibly shower mixers. Ones designed for low pressure are often far to high flow rate under high pressure.

But these are bolt on on afterwards issues.

Do size the HW tank for worst case family plus guest usage.

You should get it signed of safety isssues too. hot water at 5 bar or more is not to be trifled with.

[The Natural Philosopher]

YES!!!

Then exercise some tap-discretion or use smaller bore pipes

[The Natural Philosopher]

IF you happen to want upstairs showers you will save a fortune on pumps

I have not regretted a mains pressure system one microsecond. Nor a whole house water softener.

[Dave Plowman (News)]

He would, wouldn't he...

If you are satisfied with the performance of your existing setup as regards flow rates etc, I'd stick with it. Obviously, insulate the cylinder to a high spec - you don't need a new one for that. Changing over to a mains pressure one could well show up the limitations of those - but too late to correct.

It will also save you considerable money.

[Dave Plowman (News)]

I have an unboosted gravity fed shower and it's great. It is, however, designed for the job with 22mm feeds. Made by Aqualisa. Roughly 12 ft head

- from top of water tank to shower head.

[Roger Mills]

The water level in my header tank is not much more than 3 feet above the shower heads (one in the bathroom and one in the en-suite). But by using modest booster pumps - nothing fancy and super-expensive - I get much better showers than I do in my holiday property which has an unvented HW system.

[Mark]

That's your problem then. If you had 22mm then a mains pressure system would be excellent.

However I would always recommend keeping a header tank just for the toilets in case of water supply interruptions.

[Dave Plowman (News)]

I very much doubt the OP's plumber who is recommending changing to a mains pressure system has stated the feed to the house should be changed too. Which could cost a great deal of money.

[The Natural Philosopher]

NOT the feed to the house . That's about 30mm typically IIRC. Just the main hot and cold trunks, especially to the tank.

[Mark]

Depends on how much of it is less than 22mm.