Gravity Fed hot and mains cold!

I've just bought a house, it's a small/medium 3 bed mid terrace, I have a gravity fed hot water system however all the cold is mains pressure, This is rather inconvenient at the shower. As I see it I have two options run a cold feed from the header down to the bathroom, or install a single impeller pump on the Hot feed?

Have I got it right? It's going to be a big job to run the cold feed from the loft all through to the back of the house so I'm not hugely keen on that idea.

How do I find out what type of pump I need? do I fit it by the Bath or upstairs buy the Hot water tank?

I guess if i fit a Thermostatic mixer shower it might be capable of balancing it out?

Any advice welcome!

TIA

Mike

Reply to
Mike
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Or reduce the pressure of the mains at the shower?

Reply to
Dave Plowman (News)

Or a Venturi shower if the mains pressure is good enough?

Rob

Reply to
Rob Summers

The best place is on the outlet of the hot water cylinder, not the feed cistern. Under no circumstances attempt to pump the inlet to the hot water cylinder.

Yes. It is important that the shower is pressure balancing. This is more important than the thermostatic operation, although it should be easy to find a valve with both.

Christian.

Reply to
Christian McArdle

Yet again showing my ignorance: why not Christian?

Just curious

Mungo

Reply to
Mungo

On Tue, 16 May 2006 09:38:47 GMT someone who may be Mike wrote this:-

It does have the considerable advantage that if the mains water supply fails nobody will be scalded, provided you connect the pipe properly. Hot and cold water will continue in equal amounts and, if the cold pipe is connected properly, the hot will run out before the cold.

Consider the case of mains cold water and pumped hot water if the mains fails. Do you wish to rely on a thermostatic valve to stop someone being scalded?

Reply to
David Hansen

Because you could pressurise the cylinder - and it ain't designed for that!

Reply to
Roger Mills

Many cylinders are rated at a maximum pressure of about 3 bar. Many of the bigger shower pumps when combined with the gravity pressure available at the cylinder will exceed that!

Reply to
John Rumm

Doh... I should've thought of that. Must have been low blood sugar level at lunchtime that caused my brain fade. Thanks for pointing out what should have been obvious.

Mungo :-)

Reply to
Mungo

Had this in my last house gravity HW and main cold, right pain to get temp right and you got scolded if sometone flushed the loo.

What I did was fit shower pump (Watermill 12V) beside tank in airing cupboard, inlet 22mm cold feed straight from loft tank, hot from a warix (?) flange fitted to top of hot tank then pump outs up out of airing cupboard across loft and down bathroom wall to shower valve.

A diagram is here:-

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well. Do it right and no issues.

Actually there was a shower pump already fitted in the house under the bath (electrics attached to kitchen lighting circuit !!!) a tiny B&Q 15mm pipe cheapy pump that the previous owners had watsed their time an effort fitting in order to try an improve the shower. It was connected to the 22mm bath plumbing in an attempt to boost the pressure but just made the temperature more uncontrollable (was only a tap mixer arrangement) and just used to cavitate making an horrendouse noise as I suspect the hot pipe could not supply enough flow. My brother (a builder) removed it very soon after I moved in (and greatly improved the shower) as it was dangerous the electrics coming off a lighting circuit (as not on an isolated spur) and you also should never connect mains water to a pump.

Reply to
Ian_m

Not dangerous off the lighting circuit (assuming it had an earth if needed) as lighting circuits are protected at well below the current handling of the TW&E cable. Bad practice, probably.

Reply to
Dave Plowman (News)

It was earthed and had an isolating switch outside the bathroom, but never really used it as crap....

Reply to
Ian_m

In article , Ian_m writes

You were told off by who? And why were you told off?

Reply to
Mr X

What would be a good test of how good the mains pressure is?

I like the sound of the Venturi shower idea, heard about the venturi principals in other systems but never showers, any idea if they are prone to scaling in hard water areas?

I've seen a Jetstream model and one from Trevi Boost,is there anyone else that offers such a system?

TIA

Mike

Reply to
Mike

i'd forget about a pumped shower and fit a good electric shower as th

hot water will never run out.................... Or get a comb boiler.......

but if you want to stay as you are i'd run cold feed from the tank an fit a good power shower, still dependant on how much hot water you cylinder holds?????

-- taylor.mark1966

Reply to
taylor.mark1966

Dripping water rarely does...

Reply to
Dave Plowman (News)

On Tue, 16 May 2006 15:42:38 +0100 someone who may be "Ian_m" wrote this:-

How much does he know about electricity?

Why?

Do you mean, not isolated from the electrical system as a bathroom electric shaver socket is isolated?

You don't mean that an isolator was not fitted in the circuit, as you said in a later posting that one was.

Reply to
David Hansen

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