Plumbers, dontcha love 'em!

[peteshew]

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

[Onetap]

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).

[newshound]

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

[TheScullster]

"newshound" wrote

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

[spamlet]

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

[Heliotrope Smith]

peteshew wrote in news:a8d212fe-7a03-4560-84d3- [e-mail]:

Read this.

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: [e-mail] ---

[Andy Champ]

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

[Tony Bryer]

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

[peteshew]

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

[Onetap]

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.