Unvented hot water cylinder and Building Control

[Owain]

£1000 was probably what any self-respecting tradesman would quote to Dribble as "mate's rates"

Owain

[Doctor Drivel]

Well spotted!!!

[Doctor Drivel]

Yep, vented heat banks are far, far safer. Unvented cylinder are 99% of the time off the high pressure mains,. Some go up to 10 bar static and more when heated. That is some kabboooom

Don't think just ask.

[Doctor Drivel]

Not service!!! All control apsects have to be tested!!!! That takes "time"

To do it properly about £100. If you have an electric only unvented cylinder. The immersion is service free. So then it will cost £100 a year to store hot water. Vented heat banks are service free and don't take down the side of your house and operate at higher mains pressures.

[Stephen Dawson]

G3 of the building regs explains and to fit this he MUST be in possesion of a ceritificate of competence for UHWSS. If not he and you are breaking the law. Also is something goes wrong with the unit and it explodes you may have no insurance for the considerable damage caused. There are several things that must be done to ensure thsafe operation of this unit.

Please do not treat this lightly.

Regards

Steve Dawson (Approved G3 installation, commisioning, servicing and testing engineer)

[Jim Alexander]

These two sentences don't make sense. What are you on about?

Jim A

[Hugo Nebula]

On Sat, 17 Nov 2007 18:10:57 -0000, a particular chimpanzee, "Mark" randomly hit the keyboard and produced:

Regulation 13(4) "Where building work involves the provision of a hot water storage system in relation to which paragraph G3 of Schedule 1 (hot water storage) imposes a requirement, a building notice shall be accompanied by a statement which specifies? (a) the name, make, model and type of hot water storage system to be installed; (b) the name of the body, if any, which has approved or certified that the system is capable of performing in a way which satisfies the requirements of paragraph G3 of Schedule 1; (c) the name of the body, if any, which has issued any current registered operative identity card to the installer or proposed installer of the system".

Approved Document G says the cylinder must be installed by a card-carrying 'competent' person, and that if it's a BBA (or equivalent) approved package, Building Control don't need to inspect. IIRC, I've inspected one in my career.

BTW, it's exempt fees.

[John Rumm]

As dribble demonstrates his lack of understanding of the real risk factor... (i.e. not the static pressure)

[Ed Sirett]

Play fair! it's equivalent to having removed the brakes (foot and hand) and the steering and wired the accelerator full on. 8-)

Obviously I respect the view that many people here have that they might as well not bother with an unvented HW cylinder as they are not diy/unqualified installable. There are alternative stored hot water systems that can do the same job for about the same money with different installation issues.

Having said that if someone wants to have one professionally, legally and competently installed that is their choice. I think it's unfair to pretend that the cylinders are 'dangerous' just because they are not diy installable.

[Ed Sirett]

Not withstanding that 10 bar mains is uncommon. Nor that both pressure relief valves will have operated long before 10 bar. Nor that the real danger is safe disposal of an entire tank of 95C HW, should BOTH thermostats fail on the immersion.

There are no models that I am aware of that have relief valves set to 10 bar let alone operate normally at that pressure. Obviously there may be some units but they are unknown to me.

Furthermore the makers test the cylinders to 15 bar before they ship them.

[Ed Sirett]

I've inspected quite a few I have yet to find one that fully complies to the letter of the regulations in every aspect. The common fault is excessive length and insufficient bore of the D2 discharge pipe.

[Doctor Drivel]

But around.

Not if set for an unvenetd cylinder that can take 10 bar static.

Murphy's Law!

ACV and some OSO if I recall.

That is test pressure. Holding that 24/7 is another matter.

[Doctor Drivel]

What do you mean? A Heat bank?

They are potentially far more dangerous. You missed out the annual service charge on unvented cylinders.

[Doctor Drivel]

Are you saying anyone can fit an unvented cylinder and just call in the BCO - and NO charge?

[Doctor Drivel]

Chav, you haven't a clue what you are on about....as usual!!!

[Doctor Drivel]

Learn to read it is clear.

A service of a cylinder will be around £100 if done properly.

Again...If you have an electric only unvented cylinder. The immersion is service free.

In a vented cylinder and just an immersion heater, no service required.

[Doctor Drivel]

The first is don't get one in the first place, get a heat bank.

[Jim Alexander]

But its only the electric side that can heat enough to produce steam and therefore explosive pressure so if you have said what you meant to say its bollocks.

Jim A

[Doctor Drivel]

You still can't read or have poor power of concentration. Again...If you have an electric only unvented cylinder. The immersion is service free....and the cylidner too.

Get it? Nothing about steam at all.

[Onetap]

Like I said, Drivel is a moron. He was obviously referring to the cylinder bursting due to the steam pressure caused by an immersion heater failing 'ON', i.e., the contacts arc-welding themselves together.

And an electric-only unvented water heater would still require the safety valves , expansion vessel and drain pipes to be checked or serviced.

And a LTHW boiler could generate steam (seen that) and theoretically overheat a cylinder; a bit of a bad hair day if your boiler and unvented water heater suffered simultaneous failure of all the safety features.