Can Vented Direct Water Cylinder draw straight from mains pressure?

[rob1100]

HI
Been to a job today. No hot water. No water at all in fact from hot taps.
The job was in a shop which has no access to the building above. They reported that a month ago there was a leak above, tenants moved out and header tank was condemned apparantly.
Initially they wanted me to put in multipoints or similar to serve their needs however whilst looking around I found a direct vented water cylinder which was getting power but had no water going to it.
Suspecting that this is due to the header tank being condemned or turned off etc my question is this:

Can I tee into the cold water main supply after the shops meter and run a mains supply direct to the water cylinder?

Thus bypassing the need for the water to go up to a header tank and then back down again.

My concerns are expansion. Being that it is vented to the tank (that I cant get to see) will this be ok to continue venting here?

Also concerned about expansion back into the cold water supply coming into the bottom of the cylinder.

Have to give the customer a quote but thought I would get some experienced advice.

Thanks for your help.

dunno really

 

[leakylea]

give the customer the advice that this job is beyond your ability,
if your asking such questions about vey basic plumbing..........please do not get involved with fitting multi points etc
Mains pressure to a cylinder would rip it open ! you would risk contaminating the cold main with expanding hot water
the cylinder and tank go together dont think that it should or could be messed with, especially with obvious limited plumbing knowledge

 

[traineedrip]

Id imagine that after drawing off a sink full of hot the surge of mains would stir up the hot and mix with the cold resulting in warm water throughout the cylinder.
the water needs to be replaced gently ensuring the hot stays at the top, ready to be drawn off. it wouldnt work even if you got past the above issues

 

[Plucky]

Mains pressure into unvented cylinders only.

Please do everyone a favour and let a Plumber take care of this. No offence but its people like you that cause accidents and install dangerous work. The simple solution here would be to replace the Cold water storage tank, but i'd have to doubt your ability to even do that.

Sorry

 

[NickH]

Jeez, sometimes I cant believe the stuff I read on here.

Rob, when you turn on the cold main supply to the cylinder dont you think it might fill up and then start to continously pour water out of the vent/expansion pipe or have you worked out some sort of magical way to stop it without blowing up the cylinder ? You obviously have little understanding of plumbing systems so LEAVE IT ALONE.

 

[jonathanb]

Sorry but this annoys me - you are obviously posing as a plumber, or is this another fast tracker who's paid for a few tickets and hasn't got a scooby? Leakylea and Plucky are bang on here, i've got my suspisions what the problem is but i'm not going to pass on my hard earned knowledge to someone who can't be bothered to get his head into the basics of what used to be a noble trade.

 

[rob1100]

Wow!

Easy guys Im not a plumber and not pretending to be.

I work in general maintenance and was asked to look at this.

Pardon me for trying to gain a bit of insight into how these things work from you guys.

Would it have been better for me to barge in and do this or to take minute to seek some advice and then realise I am overstretching myself by contemplating a job like this?

I wont be doing the job but at very least I would like to have understood the processes and reasons for this.

Step off my face already.

 

[jonathanb]

Sorry - but our trade getting savaged by have a go merchants and then we get called in to sort the mess out afterwards.

 

[rob1100]

I appreciate your comments Jonathan. I have been doing general maintenance for a few years now and have had plenty of small plumbing jobs without complaints and almost all of business is repeat.
If I dont know I ask. If Im not comfortable I dont do it.
I like to think I have some integrity.

 

[migoplumber]

right attitude rob.
good luck

shaun

 

[Puddle]

right attitude rob.
good luck

shaun

I agree
Think people upset as they can see how dangerous what you suggested could be
However someone must have asked the question just before they invented the pressurized cylinder

 

[david williams]

tell them to get a plumber to sort it ,dont feel to bad because i have just had to sort out what you have just asked.this was done by a plumber who turned out to have done a fast track plumbing course,been in the game 28 weeks,had a bpec unvented cert as well.no insurence did a runer,i look forward to unvented bombs

 

[secret squirrel]

I have just read this post and as a fast track plumber, read what rob had asked and was going no, no, no. Although I couldn't have put it as correctly in a reply as wiser plumbers, I knew it would have been wrong.

However, (here goes, I'll expect a little abuse) I can appreciate rob's point, he's been given a problem by a company and tried to work out a solution. Albeit an incorrect solution, there was something in the back of his mind going, "I think it could work, but it just doesn't seem right" who'll know?

I can also appreciate the dangerous situations that we as plumbers come across and the knee jerk reaction we all sometimes have and our reaction to some pretty obvious perhaps sometimes idiotic questions we see posted (or post).

My plea too all is (if I could be as bold) try and be a little chilled,

For myself, I sometimes want to ask a basic ? that has cropped up and I can't find the answer in my books or the manufacturers inst or from the manufacturer and just don't want the abuse. I get enough at home.

Well done rob for asking........

 

[justlead1]

Hi Rob. There are many reasons why this should not be attempted. Copper cylinders as you described are rated on pressure (head) which is created by the height of the cold water cistern above the cylinder they are also vented to the atmosphere . And nothing can increase that force by accident. If a water mains feed supply was connected there is a likelihood of the seams splitting. It gets worse as the water has not been heated yet. On heating the pressure would increase massively, defiantly splitting the seams, and scalding passers bye. It goes on. Basically it would be a bomb. Unvented systems that are now available are designed and manufactured to a standard that accepts controlled main supply. But persons installing them must be qualified to comply with building regulation. Good Luck

 

[flat pack]

get your plumber in and get a quote
if your have to much on

if the plumber fair let him work it out

if you install a new hot water mini system wrong you might not see the shop the next day
i am a unvented hot water installer and i have seen a unit go bang

if you haven't time don't do the maybe crime

if its a shop with basin and wc just pop in a small electric unit 7/15 kw over the sink. supply from the main water supply.

good luck

 

[Jackbooted]

O dear !!

 

[Bernie2]

Hey! Guys anybody should be allowed to ask questions without being called names. Okay so they might not know what to do.

Telling them is partly what the forums for isn't it?

I must admit I wasn't born knowing anything at all about Plumbing, what I learnt was from others as an apprentice and off many others all through my working years. Even in college you learn off others, even the tutor usually uses a book in which somebody else has written stuff down for others to learn from.

Its not a crime to say "I don't know!" and then put forward a suggestion for correction if necessary. But any correction should be done in a nice way, after all there might be something you want to know.

 

[bobpape]

Actually lads providing the cylinder can take the pressure it can be and is done, for example in marine situations, you connect the domestic to the side of the cylinder near the top,
(and if you like put a prv in the top tapping), when you fill the cylinder with mains pressure or pumped water from the bottom the air in the cylinder is forced out the domestic pipe
and the remaining air is trapped above the domestic pipe outlet and provides room for the water to expand when it is heated, this is exactly how an expansion vessel works,
Accumulators work in the same way,

 

[flat pack]

yes but your Accumulators was much think walled than a copper cylinder
and you boat had more pipe work to the system

 

[bobpape]

I first saw it done when I was in the UAE in the 70s.

And the amount of pipework only effects the flow not the pressure

 

[flat pack]

its not the flow ,it the size of pipework i said before is for expansion

and the Accumulators like ww1 bomb / 1970

 

[stuart_craigon]

Hey, I'll help you on this one! What ever you do DO NOT attempt to connect a direct cylinder to main water, you'll kill your self and anyone else around! Contact:

McDONALD ENGINEERS
FLEMINGTON ROAD QUEENSWAY IND. EST.
GLENROTHES FIFE (Scotland) KY7 5QF​

Tel : 01592 611123

Ask for Sandy Cooper or Jamie Stewart, Say that I put you on to them and ask about their combination cylinders or "The TIMEsaver all-in-one plumbing unit" Either that or you could have a look at:
http://www.mcdonald-engineers.com/images/literature/TIMEsaver.pdf
Or
http://www.mcdonald-engineers.com/images/literature/Copper%20Hot%20Water%20Cylinders.pdf

I hope this helps. They are a good company and exelent to work with.

 

[Renewable M]

I know how hard it is to get good insurance as a specific tradesman...... its unlikely any 'general maintenance' type man is going to be insured for every discipline that he meddles with. That would be a vast policy!!!!!

So what happens when it goes wrong?