Pumped hot and cold water

[Nick Atty]

The situation: Cold water tank is in loft of 2 storey building, hot water cylinder downstairs. Original main bathroom was also downstairs.

I'd like to pump the supplies to the new upstairs shower and large bath (force for the first, speed of filling for the second).

It appears much easier to separate the cold feed to the cylinder from the rest near the cold tank and put a cold water pump in the bathroom supply here, and to put a hot water pump in near the cylinder than it would be to re-route either supply to pass near the other.

In each case there is space and convenient power to run a spur off.

There are lots of twin pumps around, some of which say they will pump multiple bathrooms, not just showers. But are there any single pumps - it seems silly (and probably bad for them) to use two with one side completely empty.

Anyone done anything like this - any obvious solutions that I've not thought of?

[Roger]

The message from Nick Atty contains these words:

Plumb the upstairs with mains cold water and have a venturi shower. No electrics required, just water pressure. If the hot water supply to the bath is in 22mm there shouldn't be a filling problem.

If you really want to use twin pumps and are worried about half being dry just plumb each supply through both sides of the respective pumps.

[IMM]

Best take the cold to the bath, basin and toilets off the tank in the loft, not from the mains. The verturi shower has maisn cold water to it and hot from tye cyoidner. Chech the shower makers specs for mains cold water pressure.

[Christian McArdle]

Yes, there are loads of single impellor pumps, from the same people who make twin impellor types. They're not difficult to find at all. However, if you go this route, ensure that you don't just tee off the supply to the hot water cylinder. This could lead to various problems, including sucking air into the HWC down the vent. It is better to add a new tank connector to the tank and have an independent pipe. Ensure that the cold feed comes off below the hot one. This means that if the water runs out, the hot goes dry before the cold, which is safer. Better a cold shower than a scalding one.

Another alternative, if you have a good high pressure and flow mains water supply is to use the cold tank for the hot water supply only and convert the bathroom onto mains cold water. A thermostatic and, crucially, PRESSURE BALANCING mixer shower will work well with mains cold and pumped hot water. It is the type of system I installed in my last house, which provided even greater flow than my purely mains pressure heat bank in the current house (at the expense of noise and loft space).

Christian.

[Roger]

The message from "IMM" contains these words:

Why use dubious quality water out of the storage tank when you can have clean water straight from the main? And you get a better flow rate as well.

[IMM]

The tank is fitted properly with the correct by-law kit the water is fine,. The water is for washing not drinking. You are using it anyway for hot water. Using the hot and cold from the same tank gives equal pressure which means you can use mixer taps.

If you want mains pressure all over, go combi or heat bank.

[Roger]

The message from "IMM" contains these words:

You know the op personally and are familiar with the state of his plumbing?

Don't you ever clean your teeth dimm?

Seen the subject line lately? The op was looking to pump both hot and cold as he had doubts about flow.

But that would give mains cold in the bathroom which you have just denigrated and a combi would give a pitiful flow to the poor fellows bath.

[Nick Atty]

Why didn't I think of that - especially when I grew up in house like that. Replumb the cold to run off the mains, and pump the hot (through new outlet as recommended elsethread). Much better. Thanks!

I don't really want to go dividing the plumbing up as it's all nicely hidden behind decent tiles, so everything would be on the mains.

Why is it done this way? As I said above, my parents (1950s) and my grandparent's (1930s) houses in Wigan didn't use the cold water tank for anything at all except as a header for the hot water. Yet all the books I've read show cold from the tank for the bath etc. The only benefit I can see is that you can flush the toilet a few times if the water is off

- is that it? And is this a problem (if this is an FAQ of some sort, feel free to send me off to it - I admit to not doing a proper search).

[IMM]

Richard Cranium, I said "The tank is fitted properly with the correct by-law kit the water is fine"

< snip drivel >

[Roger]

The message from "IMM" contains these words:

Dimm by name, dim by nature. You did indeed say precisely that but lack the mental acuity to realise that such a statement is invalid if you don't have any actual knowledge of the system in question.

[Dave Plowman (News)]

IIRC, the regs varied in different parts of the country.

You may or may not have adequate mains flow and pressure to run the entire cold direct. The use of more than one tap at the same time may effect the flow. This may not matter, of course.

[IMM]

You have a tank supplying the hot water, so you may as well have it supply the cold as well. It means:

1. Mixers can be fitted with ease
2. Water storage in case of a cut (toilets run).
3. Better when the mains supply is not that good.
4. Low pressure means cheaper low pressure taps and they are less likely top leak than high pressure.

It is not better. See above. It is best to either be all mains pressure or all low pressure. Mixing causes problems.

Some local authorities had different regs to others. Also some would also allow mains pressures in new properties with adequate mains pipes.

A great benefit in some areas. Also you can use the tank water to drink as long as you boil it.

[IMM]

Another cad who is out to take the love of Maxies life. Dim Lin the Oriental enchantress is Maxies bird mate. If you move in the horses' head will be cut off ready for action.

This Roger is back out again! The laws in this country should be stricter. How can be be let loose in such a frame of mind I don't know.

[adder1969]

The mains flow/pressure isn't very good where I live so I rely on a tank & a pump.

[Nick Atty]

But the tank already supplies both - the question was about pumping them to give a useful shower pressure, and to fill the bath quicker - and the suggestion was that I only need to pump the hot, and can use mains for the cold.

As the layout of the plumbing means a twin impellor pump can't be used easily, this sounded a good idea.

I want to be all high pressure, but not necessarily mains.

Yeah, but if I get up thirsty in the night, I don't really want to start boiling a kettle in the bathroom (where would I plug it in?).

[Rob Morley]

The house I grew up in didn't have any direct cold water - the kitchen had been moved to an extension and plumbed into the bathroom. The galvanised tank in the attic was open, rusty, had a thick layer of debris in the bottom and lead plumbing. I think maybe people worry a bit too much about some things.

[roger]

The message from "IMM" contains these words:

As I said before. Dimm by name, dim by nature. It would take no more than a couple of minutes to establish that I have been posting on some other ngs throughout the period I have neglected this one.

Too much traffic here to read it all and too much absolute crap from Dimm. Absence of the latter would go a long way to solving the former. I suppose adding Dimm to my killfile would help but that wouldn't do very much good unless everyone else did the same and then there would be no one left to save the innocent from Dimms peculiar ideas.

[Nick Atty]

As I'm the co-owner of a canal boat, I have no qualms whatever about drinking water that's been sitting in a tank for months. It's never done me any harm.

Mind you, I do tend to mix it (internally) with lots of beer, just for medicinal reasons.

[Howie]

|> The only benefit I can see is that |> you can flush the toilet a few times |> if the water is off |> - is that it? | |A great benefit in some areas. Also you can use the tank water to drink as |long as you boil it.

And this is my BIG problem with using a header tank for all bathroom cold water.

Do you clean your teeth in the bathroom?

H.