No disresepect to anyone here, but what possessed the plumber who
overengineered our replumbing (before my time) to put two water tanks
in the loft, linked together low down and fed in parallel by two
ballcock valves? Apart from the obvious two pointsof failure for no
apparent advantage, it strikes me that due to the imbalance one of the
valves will get stressed as the other fills to a higher level and so
the rubber diaphragm seal will fail earlier.

Regardless of the wisdom or otherwise of such an approach, when said
plumber failed to use any solvent weld on any joint when assembling
the overflow, causing the pipe to drip whilst we were on holiday and
so damaging the plaster and decoration it makes me remember why I
prefer to DIY [Rant mode off]

Pete

On 9 June, 10:05, peteshew wrote:
No disresepect to anyone here, but what possessed the plumber who
overengineered our replumbing (before my time) to put two water tanks
in the loft, linked together low down and fed in parallel by two
ballcock valves? Apart from the obvious two pointsof failure for no
apparent advantage, it strikes me that due to the imbalance one of the
valves will get stressed as the other fills to a higher level and so
the rubber diaphragm seal will fail earlier.

One big tank too big to fit through the loft hatch? Or maybe one's a
later addition to provide a minimum water content required by a shower
pump?

Two tanks are often installed in commercial buildings, to allow one to
be cleaned while keeping the cold water down service on.
I wouldn't have installed two float valves and there shouldn't be
water standing in the overflow pipe if laid to fall, so it shouldn't
leak even if not solvent welded (but I would).
I have seen worse (much).

"Onetap" wrote in message
...
On 9 June, 10:05, peteshew wrote:
No disresepect to anyone here, but what possessed the plumber who
overengineered our replumbing (before my time) to put two water tanks
in the loft, linked together low down and fed in parallel by two
ballcock valves? Apart from the obvious two pointsof failure for no
apparent advantage, it strikes me that due to the imbalance one of the
valves will get stressed as the other fills to a higher level and so
the rubber diaphragm seal will fail earlier.

One big tank too big to fit through the loft hatch? Or maybe one's a
later addition to provide a minimum water content required by a shower
pump?

Two tanks are often installed in commercial buildings, to allow one to
be cleaned while keeping the cold water down service on.
I wouldn't have installed two float valves and there shouldn't be
water standing in the overflow pipe if laid to fall, so it shouldn't
leak even if not solvent welded (but I would).
I have seen worse (much).

I have two ballvalves into my (single) tank to help ensure the feed can keep
up with the power shower. Apart from the "loft hatch" point, it might have
been easier to maximise the water surface height with two small tanks

"newshound" wrote


No disresepect to anyone here, but what possessed the plumber who
overengineered our replumbing (before my time) to put two water tanks
in the loft, linked together low down and fed in parallel by two
ballcock valves? Apart from the obvious two pointsof failure for no
apparent advantage, it strikes me that due to the imbalance one of the
valves will get stressed as the other fills to a higher level and so
the rubber diaphragm seal will fail earlier.

This arrangement was fitted as standard in our 1970s (originally 3 bed)
house.
I think it had something to do with the reliability (or lack of it) of the
local water supply - we live in a village outside Hull.
Only the sinks were originally fed with mains water - our toilets were
hooked up to the storage tanks!

This has advantages - having a working bog even with mains water off, so
I've left one that way.

Phil

"peteshew" wrote in message
...
No disresepect to anyone here, but what possessed the plumber who
overengineered our replumbing (before my time) to put two water tanks
in the loft, linked together low down and fed in parallel by two
ballcock valves? Apart from the obvious two pointsof failure for no
apparent advantage, it strikes me that due to the imbalance one of the
valves will get stressed as the other fills to a higher level and so
the rubber diaphragm seal will fail earlier.

Regardless of the wisdom or otherwise of such an approach, when said
plumber failed to use any solvent weld on any joint when assembling
the overflow, causing the pipe to drip whilst we were on holiday and
so damaging the plaster and decoration it makes me remember why I
prefer to DIY [Rant mode off]

Pete


No need to link tanks low down: siphon pipe will do the job for you. But if
you have more than one bathroom or shower you may need two ballcocks to keep
up with demand.

S

peteshew wrote in news:a8d212fe-7a03-4560-84d3-
:

No disresepect to anyone here, but what possessed the plumber who
overengineered our replumbing (before my time) to put two water tanks
in the loft, linked together low down and fed in parallel by two
ballcock valves? Apart from the obvious two pointsof failure for no
apparent advantage, it strikes me that due to the imbalance one of the
valves will get stressed as the other fills to a higher level and so
the rubber diaphragm seal will fail earlier.


Read this.

http://www.wras.co.uk/PDF_Files/Information%
20note%20Guidance%20for%20connecting%20storage%20c isterns.pdf

Not over engineered but seems he knew what he was doing, (not so with
the overflow though).

Stagnation very soon sets in when there is insufficient throughflow of
water. I come accross this fairly often and usually end up fitting a new
ball valve and repositioning the outlet pipes.

It is not difficult to arrange the floats to be positioned at the same
level.






--- news://freenews.netfront.net/ - complaints: ---

spamlet wrote:

No need to link tanks low down: siphon pipe will do the job for you. But if
you have more than one bathroom or shower you may need two ballcocks to keep
up with demand.


We have two tanks. The ballcock is in one, and the en-suite feeds from
the other, thus ensuring the water gets changed. There are connection
pipes top and bottom, probably to help some sort of circulation.

The reason for them escapes me. The limit on showers, baths etc. is the
hot water cylinder getting cold, not the feed from the mains.

Andy

On Wed, 09 Jun 2010 19:20:01 +0100 Andy Champ wrote :
The reason for them escapes me. The limit on showers, baths etc. is
the hot water cylinder getting cold, not the feed from the mains.

Minimum storage required is (was?) 50 gallons, and a c.w. cistern of
this size wouldn't go through the trap door?

--
Tony Bryer, Greentram: 'Software to build on' Melbourne, Australia
www.superbeam.co.uk www.eurobeam.co.uk www.greentram.com

On 9 June, 19:07, Heliotrope Smith wrote:
peteshew wrote in news:a8d212fe-7a03-4560-84d3-
:

No disresepect to anyone here, but what possessed the plumber who
overengineered our replumbing (before my time) to put two water tanks
in the loft, linked together low down and fed in parallel by two
ballcock valves? Apart from the obvious two pointsof failure for no
apparent advantage, it strikes me that due to the imbalance one of the
valves will get stressed as the other fills to a higher level and so
the rubber diaphragm seal will fail earlier.

Read this.

* * * * * * * * * * * * *http://www.wras.co.uk/PDF_Files/Information%
20note%20Guidance%20for%20connecting%20storage%20c isterns.pdf

Not over engineered but seems he knew what he was doing, (not so with
the overflow though).

Stagnation very soon sets in when there is insufficient throughflow of
water. I come accross this fairly often and usually end up fitting a new
ball valve and repositioning the outlet pipes.

It is not difficult to arrange the floats to be positioned at the same
level.

--- news://freenews.netfront.net/ - complaints: ---

Ah, I hadn't thought about stagnation. I suppose 8 years or so isn't
too bad for a diaphragm. Access was difficult so I had to remove both
ball valves entirely to service them. :-(

The water tanks are both very large (guess 500Leach) and there was
originally no power shower, but two bathrooms and four loos. He also
installed two large boilers of which one or the other has been
isolated ever since we moved in!

Pete

On 10 June, 10:28, peteshew wrote:


The water tanks are both very large (guess 500Leach) and there was
originally no power shower, but two bathrooms and four loos. He also
installed two large boilers of which one or the other has been
isolated ever since we moved in!

Pete- Hide quoted text -

- Show quoted text -

100 gallons each???!!! That's wildly oversized I think, unless you can
accomodate 20+ people.Was there some industria process going on?

The usual recommendation is that you should only have 24 hours
storage to ensure an adequate turnover of water. I'd turn off the
supply to check how much is being used each day and then, depending on
the consumption, probably permanently disconnect one. Maybe lower the
level in the other or get rid of both and fit a 50 gallon tank.