Hot water tank

[RF Lighting]

I've never professed to know what I'm doing with anything none electrical, and I've never done anything more than wire these water heaters up. I'm just asking whether I'd be allowed to replace an element.

I like asking questions and learning from knowledgeble people like your self.

What are the other safety devices on an unvented water heater?

 

[JohnD]

I thought, and am willing to be proved wrong (or right) that there was some legal framework regarding qualifications for people working on pressurised systems, no just manufacturers' instructions.

It can't be a Gas regulation, because some of them run on electricity, and it can't be an Electrical regulation, because some of them are fed from gas (or oil or coal) boilers.

(it is said to be possible, if you put enough time and effort into disabling all the overheat and overpressure safety devices, to make unvented systems turn into steam boilers, and burst)

 

[Dan Robinson]

On a direct cylinder....


Pressure reducing valve.
Expansion relief valve
Expansion vessel (or bubble depending on model).

Indirects have the 2 port valve or G3 equivalent as well.

All should be checked when work is carried out just like we have to on gas and you guys do on wiring.

Have you seen one of these go bang?

I'm in the bath at the moment, but look for "water heater blast mythbusters" on you tube. Eye opening I can assure you.

 

[JohnD]

Have you seen one of these go bang?

I bet you haven't.

 

[Dan Robinson]

Have you seen one of these go bang?

I bet you haven't.

And?

The fact that is haven't is totally irrelevant.

They can and have. They devices are in place to prevent that from happening.

Stuffing them full of PTFE might stop them leaking at the joints, but it won't stop several 000,000's of litres of superheated steam escaping a metal container likely to be splitting into lots of shrapnel is it?

 

[JohnD]

see my earlier post.

 

[Dan Robinson]

What misinformed twaddle would that be then?

 

[JohnD]

don't be silly.

I thought, and am willing to be proved wrong (or right) that there was some legal framework regarding qualifications for people working on pressurised systems, not just manufacturers' instructions.

...etc.

 

[Dan Robinson]

It will be the building regulations, followed by criminal charges if anything goes wrong.

I fail to see you asking me if I have seen one go wrong is related to the question on legal framework.

Star Elementary is one to look up. School in America that went bang killing lots of kids.

Watts industries introduced the idea of safety devices on these things and film they made to prove the point nearly sent them out of business.

Interesting DVD that one.


So yes, I have seen them go bang; but no, not in the flesh. And long may it remain so.

 

[droo77]

It has how-den we101 on a red cover 3kw

 

[JohnD]

do you mean a red jacket on a copper cylinder?

or do you mean the cylinder is red-painted metal?

a photo would be useful //www.diynot.com/forums/viewtopic.php?t=129539

is it an unvented cylinder?

what colour is it, and is there a name printed on it?

is there a cold-water tank in the loft, or on top of the cylinder?