expansion vessel unvented

[REDSAW]

can you change one without having an unvented ticket or cant you touch them at all/?
dont get many round here but sods law got one today just blowing water out the scrhader valve and lost all pressure

 

[Best]

You would need the ticket. To keep any warranty it would need to be whatever make of vessel the u.v. Unit manufacturer recommends.
Obviously it has to be the right size & potable, but also the air charge would need to be to suit the u.v. tank & the mains pressure.
The diaphragm can be replaced in the vessels but you are better a whole new exp vessel.

 

[REDSAW]

thanks best, the installation is around 15 years old so not sure of any wntee only the cylinder itself!.,.
its a telford tempest if i remember right.

 

[Best]

thanks best, the installation is around 15 years old so not sure of any wntee only the cylinder itself!.,.
its a telford tempest if i remember right.

Warranty is 25 years, but only with a record of yearly servicing obviously.
I know the Telford Tempest well, - was at one a few hours ago! The expansion vessel is normally Zimmet I think, & it should have a 3 bar air pre charge, but I would always check it with a pressure gauge before fitting. If the mains pressure is capable of doing the 3 bar max then the expansion vessel should be left at 3 bar or
Just slightly less. I think the e.v. are recommended to be changed every 5 years.
Really need to do a service on the u.v. when you touch anything. The actual pressure at the PRV needs checked, the relief valves need opened & the exp vessel needs air charge done. Also the discharge pipe needs checked in case it is too small etc. Hardly rocket science I know, but worth taking a few minutes.

 

[arran197]

It's something I would like to know about, what do and don't you need your ticket for on an unvented. I imagined that the vessel would require a ticket, as would the PRVs and the Temp release valves.

What about the zone/2 port valves?

 

[Best]

It's something I would like to know about, what do and don't you need your ticket for on an unvented. I imagined that the vessel would require a ticket, as would the PRVs and the Temp release valves.

What about the zone/2 port valves?

The unvented units own motorised valve would require someone with the ticket I would think, as it is one of the units safety parts & cuts the heat to the unit. Any other zone valves not part of unit would not require the ticket. Would be an easy job to replace any of the PRVs, etc, with the correct new parts for any plumber with a clue, but obviously the problem is they are then responsible. The unvented ticket is well worth having.

 

[chris watkins]

It's something I would like to know about, what do and don't you need your ticket for on an unvented. I imagined that the vessel would require a ticket, as would the PRVs and the Temp release valves.

What about the zone/2 port valves?

Hi Arran & Redsaw why don't you do the short course (it is not just the un-vented but all hot water now !!) it's only a few hours of reading the manual & a one day at the training centre should not break the bank either, go on book yourself in.
Always best to charge the vessel up to the same pressure as the pressure reducing valve setting (as we don't have control over mains pressure) even if the working pressure is normally lower.

 

[arran197]

Hi Arran & Redsaw why don't you do the short course (it is not just the un-vented but all hot water now !!) it's only a few hours of reading the manual & a one day at the training centre should not break the bank either, go on book yourself in.
Always best to charge the vessel up to the same pressure as the pressure reducing valve setting (as we don't have control over mains pressure) even if the working pressure is normally lower.

My supervisor has mentioned sending me up to Leeds to do the unvented course. Hopefully he'll act upon it as we're getting more and more properties with them now.

 

[tamz]

it is not just the un-vented but all hot water now !!

Obviously because there are so many out there (and i've seen a lot of their work) who don't even know the basics of plumbing. That's modern training for ye.

 

[chris watkins]

Obviously because there are so many out there (and i've seen a lot of their work) who don't even know the basics of plumbing. That's modern training for ye.

I am sure you will agree Tamz it depends what the quality of the training is like ??

I recon at least 75 -80% un-vented HW system I go to have installation faults & it has been like that since the 80's.

 

[tamz]

I recon at least 75 -80% un-vented HW system I go to have installation faults & it has been like that since the 80's.

Most of the early ones were fitted by unregistered plumbers who couldn't read :smile:

 

[Best]

Worst I have seen was a brand new install done by a plumber.
He had fitted a 15mm small lever valve between the pressure relief valve & the start of the d1 pipe - heavens knows why! But it got worse, the d2 pipe he reduced to 15mm & ran it approx 4metres through the upstairs bedroom & then outside wall & stopped! Great if the unit discharges potentially scalding water at very high pressure above someone outside & the tundish overflowed even when a relief valve was tried!

 

[Best]

Most of the early ones were fitted by unregistered plumbers who couldn't read :smile:

You are right, - the instructions are fairly clear & the sizing of the d2 pipework is a standard formula, so anyone who takes care to read the u.v.s instructions should have no excuse.

 

[acecharly]

I dont think a warranty ticket should make any difference if you havent got a ticket to do a job dont do it flat out weather you think you know how to do it or not. Look at it this way would you be willing to defuse a live bomb with no training because as most here know the consequencies can be just as bad.

 

[GrahamM]

You are right, - the instructions are fairly clear & the sizing of the d2 pipework is a standard formula, so anyone who takes care to read the u.v.s instructions should have no excuse.

You would think wiring up the stat was a standard formula as well!
Loads of poor instals out there.

 

[Simon F]

Hi Arran & Redsaw why don't you do the short course (it is not just the un-vented but all hot water now !!) it's only a few hours of reading the manual & a one day at the training centre should not break the bank either, go on book yourself in.
Always best to charge the vessel up to the same pressure as the pressure reducing valve setting (as we don't have control over mains pressure) even if the working pressure is normally lower.

read this the other day but it was going through my mind today, the highlighted part,
more explanation please,

 

[chris watkins]

read this the other day but it was going through my mind today, the highlighted part,
more explanation please,

Your wish is my command Simon, Part G 3 now covers all hot water systems not just un-vented, that is why they felt the need to make it a 5 year RE-ACS I assume.
There are now minimum requirements for things like plastic cistern bases & open vent sizes, controls - what to do if it has doesn't meet any these.
There are some changes to the un-vent bits but also the requirement for blending valves on every new bath installed to control water temps to max 48 deg C etc.
Hope that helps, it is only a 1/2 day up-date, so not to bad if you get the right teacher !!

 

[Simon F]

thanks for the reply Chris, I do have the unvented ticket.
I suppose the thought based on what you said was, do you need the G3 certificate before touching any hot water controls, pipes etc??

 

[chris watkins]

Think I understand, my take on it, is that officially you should now have the ticket to work on any hot water system, vented or un-vented of any size, so from instantaneous up to 500L, combi's, cylinders & thermal stores etc all are now covered by it.

 

[REDSAW]

Think I understand, my take on it, is that officially you should now have the ticket to work on any hot water system, vented or un-vented of any size, so from instantaneous up to 500L, combi's, cylinders & thermal stores etc all are now covered by it.

naaaaaaahhhhhhhhhhhhhh!

 

[chris watkins]

We like constructive debate & critical evaluation at this end & naaaaaaaahhhhhhhhhhhh! is nothing LIKE it!!!! LOL

So what's your take on it then RED ???????

 

[REDSAW]

yer saying to work on a combi you need a g3, hows that work, officially?

or even change a header tank, you need to 'officially' be ticketed!.

 

[kay-jay]

Hw is covered by wras
Unvented by g3 ticket.

Some training centres may use the opportunity to update you on other changes when renewing g3 but its not a necessary ticket for anything other than Unvented

Sent from my GT-I9100 using Tapatalk 2

 

[BLOD]

I'm with cw on this one.
Since 2010 approved doc G covers unvented & vented, so my take is you have to have the ticket to work on either.

 

[BLOD]

It's under the G3 bit

Amendments to Part G of the Building Regulations