unvented indirect system - gravity HW, Pumped CH, now no HW

[awils101]

Hi all,
I recently installed an unvented indirect hot water tank in a gravity HW, pumped CH system. I changed HW pipe from 28mm to 22mm a metre or so after the boiler(Potterton e60) as tank required 22mm. CH works fine, but HW from boiler doesn't reach tank. I'm suspecting an airlock, but efforts to back flush haven't worked, possibly due to location of drain valves.

What I'm thinking now is to either add a bleed valve near highest point of HW circuit and/or moving to an S-plan system, hoping the HW pump resolves any issues with airlock and changing from 28mm to 22mm pipe (i've read on a previous post this probably was not wise).

how much effort is it converting the gravity system to fully pumped s-plan?

Any advice is much appreciated.

Thanks.

 

[Bambergaspipe]

Hi all,
I recently installed an unvented indirect hot water tank in a gravity HW, pumped CH system. I changed HW pipe from 28mm to 22mm a metre or so after the boiler(Potterton e60) as tank required 22mm. CH works fine, but HW from boiler doesn't reach tank. I'm suspecting an airlock, but efforts to back flush haven't worked, possibly due to location of drain valves.

What I'm thinking now is to either add a bleed valve near highest point of HW circuit and/or moving to an S-plan system, hoping the HW pump resolves any issues with airlock and changing from 28mm to 22mm pipe (i've read on a previous post this probably was not wise).

how much effort is it converting the gravity system to fully pumped s-plan?

Any advice is much appreciated.

Thanks.

Being qualified helps, try getting your g4 certificate, A*sswipe.

 

[spacethegas]

wots a g4 cert is it unvented h/w.

 

[DP]

Aforementioned certification is mandatory to installation of unvented cylinders. This certification would have told you, you cannot have gravity circulation on UV systems. If you got this little gem wrong, there is a good chance you have other errors in place as well.

Do remember, safety controls and clearances are there for your safety. Ignore this if you want to be in orbit round the earth.

Building Control notification is also required.

 

[WDIK]

wots a g4 cert is it unvented h/w.

its a bit like a G3 except if you dont know what your talking about, then it completely reveals that fact

 

[awils101]

Thanks, Bambergaswipe, glad to see your upholding the general publics view of those in the plumbing trade.
I see not all posts on here are from plumbers, as people are trying to do things themselves, and they still seem to find advice. I was hoping people genuinely interested in helping others would respond. Does anyone else have any useful replies to my question?


dp, thanks for reply, can you tell me why an unvented system cannot be used with a gravity HW system, the closed HW circuit seems the same, except for the addition of a 2-port valve?
If that is the case, then I'll have to convert to a 2-zone system.
Do you have any practical advice for doing this?
Yes, one bit of advice could be that I could get someone in to do this, which, but don't want to end up with anyone like Bambergaswipe.

Thanks.

 

[D_Hailsham]

The point Bambergaspipe and others were trying to get across, unsuccessfully, is that DIY installation of an unvented hot water cylinder is illegal. It must be done by a person who has the appropriate certificate (a G3 certificate). The work also has to be notified to the Building Control Dept of the Local Council; this would normally be done by the approved installer.

 

[spacethegas]

wots a g4 cert is it unvented h/w.

its a bit like a G3 except if you dont know what your talking about, then it completely reveals that fact

ive got on unvented ticket.
just never heard of G3 or G4.
theres no mention of it on my card.

 

[namsag]

Bamber may have been slightly abrasive with you but his point is right you don`t have a clue and have a potential bomb installed that can take your house out and next door.
Get the right person in even someone like bamber as they may just save you and your kids lives or if your lucky a severe scalding.
And its not just an addition of a 2 port valve its a certain type of 2 port valve. Do you know which as this is basic also

 

[D_Hailsham]

just never heard of G3 or G4.

No such thing as G4, that was a wind-up.

G3 is the number of the relevant paragraph in the Building Regulations SI 1991/ Schedule 1 Part G


Hot water storage
G3. A hot water storage system that has a hot water storage vessel which does not incorporate a vent pipe to the atmosphere shall be installed by a person competent to do so, and there shall be precautions—

(a) to prevent the temperature of stored water at any time exceeding 100 C; and

(b) to ensure that the hot water discharged from safety devices is safely conveyed to where it is visible but will not cause danger to persons in or about the building.

Approved Document G says:

Under Regulations 13 and 14 of the Building Regulations 2000, a person giving a building notice to, or depositing full plans with, a local authority must, where the work involves the provision of an unvented hot water storage system, provide a statement which specifies:
the name, make, model and type of hot water storage system to be installed;
the name of the body, if any, which has approved or certified that the system is capable of performing in away which satisfies the requirements of paragraph G3 of Schedule 1 to the Building Regulations;
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.

The Water Supply (Water Fittings) Regulations 1999 (SI 1999/1148) also apply.

 

[awils101]

o.k. thanks to all that replied in a manner befitting the human race unlike the first guy, whose not even worth a second mention - however I don't think anyone has tried to answer my question about the air locks etc.
Everyone has been too tied up talking about a different topic.

None of you ever been in a situation whether qualified or not and had to ask someone elses advice - just like I'm doing on here?
...or like the electrical trade, unqualified people do the work and get others to sign it off?

I've previously read the G3 Regs and adhered to them apart from the qualification bit.

 

[JPC]

awils........you need to clarify with us what you´ve fitted...you state its unvented cylinder and gravity ??

so do you mean its unvented and the primaries are gravity ....or do you mean a vented cylinder or do you mean unvented cylinder fitted as a vented.

Folk here, albeit not telling you why, are right to advise you ...a wrongly installed unvented cyclinder could be lethal (boiling water turns to steam on pressure drop and could explode the cylinder...and i dont mean a leak...a explosion to blow walls down)

It therefore might be wise to try and comfirm what you have installed.

 

[Registered Gas Man]

Bambergaswipe

Sorry I had to post, this just made me laugh so hard!

 

[mickyg]

I've previously read the G3 Regs and adhered to them apart from the qualification bit.

yeh, " I drove a car around, I stuck to the highway code, just not the the having a driving license bit"

Pure and simple you are breaking the law by installing and working on this, that is why no one is helping you. The fact that you don't have the necessary knowledge to know how to finish the job shows you are not competent to be doing the work, qualification or no qualification. This is not just a water tank, wrongly installed it is a potential bomb. Do the sensible thing, stop work, call a qualified engineer and get them to finish the work.

 

[namsag]

I have asked peoples advice on stuff that i have not been trained in , but being someone who works with there hands everyday and thinks through how to take things apart and put them back together and has a reasonably good mechanical knowledge of most things and understand how they should work .I feel i can.
The first thing i would do is read any instructions that comes with the VERY expensive bit i had bought and somewhere in there it will say it must be fitted by a registered guy on a fully pumped system with a spring return motorised valve.
For some reason you feel capable of doing this by asking questions on the net but are missing even the basics so can you not see why people are holding back info from you.

Genuine honest question from a diyer i will always answer and give advice but when you get the halfwit who thinks everyone is out to rip them off and is ignoring good advice given to leave well alone . Whats the point they will carry on regardless. Hope he only damages his own property