Indirect vented cylinder - feed from mains instead of water tank. Doable?

[kozel]

Hi,

I am having my bathroom refurbished and had some builders in for a quotes. As part of the refurb, we want to install a mixer shower that requires at least 0.5bar. We have a standard gravity fed system (water tank in a loft) with indirect vented HW cylinder (in the airing cupboard in master bedroom). I assume it gives max. 0.25bar (bathroom directly above the loft).

One builder suggested feeding HW cylinder from mains rather than water tank. However intrigued I am by this option, it also set some alarm bells in my head (how do you stop cylinder from overfilling, what is the point of the tank after this or damage to the piping which may not be designed for this pressure). I have looked at the internet and basically found only 2 threads about this (bad sign?). One was basically saying something like 'DO NOT do it unless you want to wake up in your neighbor's bed or not at all...' and one saying that 'it is quite common to do this in mainland europe' (even found a schematics for it - it is done by installing pressure reducing valve, strainer and non-return valve).

Therefore my question is, is it doable/safe/viable in the first place?

Obvious alternative would be to install water pump, but we really could do without the noise as well as extra mechanical part that could potentially go wrong. Unless someone knows about some ultra quite pump...

Many thanks in advance for you comments.

 

[Simon F]

NO.
the builder is mental or its a misunderstanding.
you can get an unvented cylinder fitted or fit a shower pump.
what is suggested is a bomb making lesson !


just to clarify, I am thinking you are talking about adapting the existing hot water cylinder??
this would be dangerous illegal etc.
you can get an unvented cylinder tht is fed from the mains, gives better flow and has no tank in the loft.
not a cheap option and has to be fitted by someone suitably qualified.
very unlikely to be the builder.

 

[Irish]

Yeah Simon is spot on, did the builder get a mains feed cylinder? ie unvented

 

[lame plumber]

Paddy and Shaun have moved out of driveways into property development.

 

[PlumbBobBob]

in a word no. not a very good idea, a standard cylinder isn't designed for pressurising. i would go with a stuart turner pump myself, they are just about the quietest of pumps.

 

[Best]

Why ask a builder?
Ask the builder why he is an expert on plumbing systems. Also ask him for his qualifications.

 

[CMcM]

dont get a builder to do a plumbers job, if u want a pressurised system go for an unvented system installed by a competent person 🙂 you, the wife, kids + dog will be safe. may be a bit more expensive but no where near as many probs as letting the builder do it.

 

[kozel]

No, I don't think he mentioned replacing the cylinder for unvented one.

But from what you saying, it is madness...

 

[lame plumber]

wrong order, dog,kids and wife🙂

 

[kozel]

It's only my wife and our cat so collateral damage really... 😛

 

[dontknowitall]

I wonder if we're jumping to conclusions here. Could be the builder has seen unvented cylinders, knows they're pretty good for showers, but leaves all the plumbing and final plumbing advice to his plumber.

The builder I used for years knew all sorts of stuff in construction but had a whole host of people to call in, e.g. electrician, plumber, roofer, joiner, decorator, etc, etc and all the builder stuck to was basic brickwork and stonework and project management.

 

[stoker122]

NO.
the builder is mental

PMSL Simon.
Clarify with your builder, there is every chance he was talking about replacing the cylinder, no-one is that mental surely.

 

[Simon F]

I did give the option of mental..:bomb:.. or misunderstood..:confused5:.
it is one of those, which one???

 

[kozel]

No offense, but reading here I would be inclined to go for option number 1 since he is aware that there is a tank in a loft (asked him to replace an intake valve since it caused the piping to rattle inside the walls) and he also inspected the cylinder. I don't recall us having conversation about replacing it (I did not even mention this when placing an ad).

 

[plumber0808]

As said the builder will probably leave it to the plumber to run through it with you, but please ask that he does.

builders can't do plumbing, they think they can and tell you they can but it always looks a mess.

Flexi pipe galore

 

[AWheating]

worst things have been done by builders.

 

[Killy Bing]

Eee "miss i have installed the mains to your cylinder, as you can see its such an effective practice it causes your vented cylinder to grow in size!"

*looks at the torpedo forming*

 

[Mike Jackson]

PMSL Simon.
Clarify with your builder, there is every chance he was talking about replacing the cylinder, no-one is that mental surely.

Unfortunately they are. I was in plumb center when someone came in and asked for a pressure reducing valve so that they could do away with the cold water storage cistern and improve their hot water fow rate.

 

[happyflyer]

Eee "miss i have installed the mains to your cylinder, as you can see its such an effective practice it causes your vented cylinder to grow in size!"

*looks at the torpedo forming*

Oh Mr 1King how big will it get, " just say we Miss"