swaped cylinder now water wont circulate ????

[Agile]

I dont understand what you mean when you say that you fit unvented cylinders for your work.

If you really do that and do not have the unvented qualification then your employer is acting very irresponsibily.

Although many others are very naive, I would never encourage or give advice to anyone to help them to do anything that they are not qualified to do. We even had someone trying to give advice here who did not know that you needed to have a qualification for fitting unvented !

Tony

 

[chrishutt]

We even have a lady trying to give advice here who did not even know that you needed to have the qualifications for unvented !

Tony, sometimes you sound like the classic male chauvinist! All your references to woman seem to be tainted by disdain for their efforts in the technical arena, unless you're complimenting them on their appearance.

I don't think the poster in question gave significantly misleading advice. Perhaps her advice wasn't the most useful or relevant, but who amongst us can claim always to have been spot on with our advice (except ChrisR of course)?

 

[bmx]

I dont understand what you mean when you say that you fit unvented cylinders for your work.

If you really do that and do not have the unvented qualification then your employer is acting very irresponsibily.

Although many others are very naive, I would never encourage or give advice to anyone to help them to do anything that they are not qualified to do. We even have a lady trying to give advice here who did not even know that you needed to have the qualifications for unvented !

Tony

tony you guys have got me worried now.... i will tell the manager on monday morning that for the last 5 years me and 13 other blokes have been fitting andrews water heaters elegaly. i will come back and tell you what they say. what about undersink unvented water heaters? i suppose they come under the same cat dont they. we fit 1000s of these every year. and not one of us has a qualification.

 

[Agile]

It could be that you have a foreman or similar with the qualification and they consider that is adequate because he inspects every job. It will be interesting to see what they say! If thats your normal work you should press for them to get the qualification for you.

The unvented Regulations only apply to cylinders OVER 10 litres so there is no requirement for the qualification to fit the under sink ones.

Chris, you seem to have missed my post about the Ideal lady with the PhD? I doubt that ChrisR claims to get everything right first time, in fact he seems heavily into "unknowns"!

Tony

 

[bmx]

It could be that you have a foreman or similar with the qualification and they consider that is adequate because he inspects every job. It will be interesting to see what they say! If thats your normal work you should press for them to get the qualification for you.

The unvented Regulations only apply to cylinders OVER 10 litres so there is no requirement for the qualification to fit the under sink ones.

Tony

the foreman has not got a certificate.

the under sink heaters we fit are santon au7 so like you say they are under the limit. but wouldnt 10l of boiling water exploding in front of you followed by shrapnal of plastic and metal, be just as pleasant

anyway i will see what they say and push them for a certificate from the citb

 

[bripl]

now you have frightened the guy PLENTY OF COMPANIES have installers who do not have the g3 cert i done the unvented course back in the early eighties valid for five years,have never renewed it since am i incompetant? have never had an incident with them yes they CAN be dangerous but do not blow it out of proportion if it has been fitted on gravity supplies IT WILL NOT WORK CORRECTLY IT MAY BE DANGEROUS so as chris r has pointed out why not read the instructions they are there to help you.you will need to repipe and put the controls in the correct sequence and have it wired by a competant electrian,who by the way does not require a ticket as the main reason for explosions are from OVERHEATING not poor or faulty plumbing[electrians failing to understand how to wire correctly]

 

[chrishutt]

Chris, you seem to have missed my post about the Ideal lady with the PhD?

Tony, since you implicitly dispute my suggestion that you are being a male chauvinist, may I draw you attention to this quote of yours (31st May)-

"Poncho" is having so much difficulty with a simple task that it could well be a woman!!!

 

[ArtfulBodger]

The unvented Regulations only apply to cylinders OVER 10 litres so there is no requirement for the qualification to fit the under sink ones.

That's odd. I could swear that I put down 15 litres on my exam paper

 

[bmx]

its 15L ive just read them

 

[ArtfulBodger]

its 15L ive just read them

Sorry to accuse you of trolling bmx, my suspicious cynical nature

P.S. The g3 exam is by far the easiest examination in the world to take, easier than getting an A* gcse (according to the daily mail)

 

[ChrisR]

You don't have to have passed a test to fit unvented cylinders, and you don't need to be registered with the CITB.

You only have to be competent.
If BMX's employer trains his own guys, fine, though if there were a claim of some sort he'd have some convincing to do.

Though I didn't allow for someone fitting unventeds without a fairly good knowledge of heating systems (nb I was wrong there, see) there's no reason why the "normal" career route need have been taken.

Though it says in the instructions that gravity flow is not OK it doesn't say why - there's nothing about the cylinder being unvented or not which determines whether gravity circulation will work. The principle is simple enough, hot water is less dense than cold so the circulation-driving force is the difference between the pressures of the water at the bottom of each side of a vertical loop.
I think, though I'm not sure about this, that if you could somehow give the water in bmx's loop a shove round, it would keep circulating. What's missing in the new cylinder is the vertical coil of pipe which presents the hot input at the top and the cold outlet at the bottom. In this and many unventeds the connections are side by side, so the loop internally would have to go down then up, which would stop circulation starting up. "Anti-gravity loops" are of course used for just that purpose.
Some eg Megaflo have the primary water rising in the coil. This helps heat transfer a little but certainly needs pumping.

 

[bmx]

What's missing in the new cylinder is the vertical coil of pipe which presents the hot input at the top and the cold outlet at the bottom. In this and many unventeds the connections are side by side, so the loop internally would have to go down then up, which would stop circulation starting up

ok now i understand the difference. it is the type of coil thats inside then. so in the original its just a small coil going from the inlet and coiling down 10 inch to the outlet. water cools down and drops back to the boiler. in the new cylinder the coil goes down 10 inch then back up 10 inch, but by the time the hot flow has gone down its cooled and doesnt want to move anymore.....so its then stoped the gravity feed...thanks you lot for all your help. i was gonna ditch this forum, but your not a bad lot after all.

 

[ChrisR]

 

[CopperCylinderMan]

Just FYI, there is an unvented cylinder, fully approved and suitable for gravity primary circulation.....Its got a 28mm constantly rising coil.

The last time I posted a link though, I was accused of advertising!

CCM

 

[breezer]

i have been reading this post and not being a plumber or heating engineer i wonder could some one tell me why you cant (as poster claims to have done) swap an "imersion heater cylinder" to a "mega flow stylie one"

i understand that a megaflow has an air bubble in it and the thing is under pressure (i did here about one in a well known burger chain that did explode, also the installation / training video where one took off and went through the roof) i have no intention of fitting one, just curious about them, i have also seen a corgi card, if i were to see another how would i know if the card holder is"cometant to fit a megaflow" does it say somrething else? again just curious

I also understand if you do not want to say on a public forum, my email is in my profile