Home DIY

I've got a pressure tester as well. you just screw it onto the tap (if it's a garden tap anyway) it's in se24 if you want it. Sure you can get some bodging bits and clamp it onto a normal tap or something if you need to. They're only 12 quid or something anyway.

I've got crosswater bits. They are the stuff you get from bathstore, right? runs fine off my combi. I had a water tank but i just put a loop in before it so the cold water is all mains fed now. Works pretty well but if anything it's too hot sometimes. I'm sure you'd be fine but I'm not qualifird to have an opinion so take that with a pinch.

The mains pressurised systems are good, megaflow is the standard brand and almost all modern installs use them. As said above ^ you've got to hope the extra pressure doesn't pop any old fittings but i've never seen it happen. You'll need a plumber and a reasonable amount of cash for it though. upward of 1K probably. Though you can get cheaper used cylinders on ebay, they are usually fine as there's no moving bits in them anyway. Pumps seem like a bit of a hassle to me, plus they are noisy. And do you really need that much pressure / waterflow? It will empty your hot storage tank in no time.

B

Would the press. storage cyl and expansion tank fit into the same space as the immersion heater? The main idea of installing this setup would be to free up some cupboard space by negating the need for cold water tank along with having proper pressure from the bath/shower fitment (the flow almost stops when you get it head height).

Economy 7, yes.

I'd taken photos of the current setup to get a quote with but they must be on the old phone.

Guess it would help if I knew the capacity of the current one. Any idea what's suitable for a 1br flat?

The cylinder will be no bigger than what you probably already have. I guess a 150 litre will be ample if not a smaller 125 litre. The bigger the cylinder you can fit in, the more cheap rate hot water you will have stored to save heating water at the dearer daytime rate. The expansion vessel will just screw to the wall above the cylinder somewhere and is about the size of a bucket.

You will need an overflow pipe with a visible discharge outside. There is a thing called a tundish which goes beside the tank. This is in the pipe that feeds the overflow and allows you to see if any of the temperature / pressure relief valves have operated. There's also a pressure limiting valve to restrict the mains pressure to a safe level so a few extra bits of plumbing to fit in.

Also you will have to swap your cistern valve for a high pressure one and similarly the bath and basin taps.

None of this is based on anything other than experience - I'm not a plumber. #disclaimer

Cheers for the info. I won't be doing it myself so I don't need to know too much about the install.
I'm pretty sure it's meant to be done with local authority permission or some crap anyway and for stuff like this I'd rather have a pro do it. Just knowing what options are available is nice though.

A guy here mentioned instant hot water. I know you can do this with gas. I imagine it would it be pretty expensive to do on electric?

Same principal as an electric shower surely?

Cheers for the info. I won't be doing it myself so I don't need to know too much about the install.
I'm pretty sure it's meant to be done with local authority permission or some crap anyway and for stuff like this I'd rather have a pro do it. Just knowing what options are available is nice though.

It is illegal to work on unvented systems unless suitably qualified so no choice in the matter(although you could in theory do the install and have it commissioned by an 'expert').

This of course means I did not repair one of these systems recently. In fact I was nowhere near the place on the day in question...

Does that extend to the central heating pipework, or just the boiler itself?

My earlier comments refer to pressurised hot water systems and, I think, the tank components only. That's the area that can go bang if a fault developes.
Similarly, with central heating, the danger area is the boiler. Pipework, I believe is OK.
I'm pretty certain that it's fine for anyone to fit a boiler, plumb it in, etc. but it needs a qualified person to make the gas connection and commission the unit.
^All bar room lawyer talk!

Same principal as an electric shower surely?

Yes, which are expensive.

I don't have room to add a coal mine either.

Expensive to run, or to purchase?

With a combi boiler you always have a lag between turning on the tap and hot water appearing- unless you have a storage combi which keeps a small tank of water hot, ready for you to turn the tap on.

Seems a little profligate when you can just wait ~5 seconds for the water to come through hot though.

You can also get those hot water taps which have become all the range for the Clapham "big house and an Estonian nanny" set, which does away with the need for a kettle as they provide instant very hot water on demand.

With your heating system being electric I imagine that you set it to turn on overnight when electricity is cheap, it then heats up the tank and you use that stored hot water in the morning to shower with- is the problem that the water is going cold before you are finished, or that it is not warm enough?

I fucking hate economy 7. had it in a house in Belfast. would never remember to close the vents overnight so the heaters (i say heaters plural but there was only one, in the living room, at the other side of the house) would always be stone cold when we needed them.

They're expensive to run according to the sparky that fixed ours. No idea how much the big ones are.

The boiler would only be for hot water, not heating so wouldn't be a combi-boiler, assuming I'm understanding what 'combi boiler' means here.

I have a coffee machine with hot water so don't need or want a instant-hot zip tap.

The problem is lack of hot water pressure. This is why I was considering the unvented system.
I would also like to get rid of the cold water tank if possible to free up a big chunk of cupboard space.

stevo: Our flat is pretty warm - double glazing, etc so I doubt we'd have any Belfastesque issues. The water isn't the hottest at the end of the day but we have a really old immersion heater and crappy insulation on it.

You could (possibly- speak to a plumber) just fit a pump?

They are designed to give vented systems a big boost in pressure (from what I understand) and they crop up on eBay all the time for a fraction of their new cost.

The issue is (I think) that your system works by heating the water up ahead of demand, then it is released from a storage tank, hence you lose the pressure that it had when it entered the building from the mains.

Whereas a combination boiler (central heating and domestic hot water combined) heats the water "on the fly" as it were, so whilst there is some reduction in pressure the water is still ~80% of mains water pressure when it hits the shower head.

I have to admit that I don't know why you would need a cold water tank these days- going on the basis that I don't have one, and I live ~300 feet above the level of your flat, and my water pressure is great.

This is with me having replaced every single last bit of plumbing that was in the flat when we bought it a year ago, so I'd have spotted a cold water tank hiding somewhere I think.

I noticed it, I demolished it- now I'm replacing it!

Purely because it's cheaper to put it back than it is to get the lease altered, it's never going to be used.

Bricks are cheaper than laywers.

I have to admit that I don't know why you would need a cold water tank these days

The flats were built in the 60s I think. Maybe water pressure was shit back then?

You could (possibly- speak to a plumber) just fit a pump?

Noisy though and I was aiming for a more efficient setup at the end of it all, not something that uses more power. The immersion heater is OOOOLLLLLDDDDDD..

All comes down to the price of electricity, gas, and the costs of upgrading your plumbing.

Also, what an upgrade would mean in terms of the value of your flat- for example even if you are not planning on selling it, if you increase the value through improving things such as the heating you can get a significantly better deal when you move your mortgage, as you have increased your equity in the property.

For showers, if you want high pressure and instant hot water, I reckon a gas fired combination boiler would be idea- with that you would have zero tanks, anywhere, but you'd need radiators, and a lot of plumbing done.

And, you don't have gas.

But, it might be worth it in terms of reduced bills, mortgage and of course the ability to have a hot shower at once.

And you get your cupboard for midget storage.

gas fired combination boiler? Flats can't get gas.

Elec combi boiler vs. electric unvented hot water?

I have never heard of an electric combination boiler- and I suspect one does not exist. But who knows, I'll have a Gooogle.

Back to electric unvented hot water as the best option I think.

Hah- don't listen to me

http://www.diynot.com/forums/viewtopic.php?t=247726

A combi-boiler just means hot water + heating, right?*

*

So, no point if I just want hot water upgrade and don't want to install radiators.

I believe so.

Oil fired boiler, get a tank outside?

Yoru neighbours would love that!

Oil? No thanks.