unvented problems

[skipup]

Hi there, can any body help me out ? my unvented cylinder has also had the c/heating expansion vessel pipework plumbed into the d1 pipework! the expansion vessel for the u/v cyl is then plumbed into the d2 pipework?. the d2 pipework then bridges back into the cold supply in via a 15mm f/w gate valve this all seems rather odd to me any explanations????:sad_smile:

 

[bob the plumber]

take a picture.. no problem with ch expansion being teed into d1 before tundish, as it will discharge safely and will be visable through the tundish. the hw expansion however is incorrect if you have explained it correctly as it should be the first input into d1 to the tundish

 

[skipup]

thanks bob thats as i expected! still dont understand why the d2 pipework bridges back into the c/w supply pipe through a gate valve ?

 

[bob the plumber]

it really cant be doing that mate im convinced your maybe looking at it wrong, gate valves arent the best with holding pressure, your cold main will just end up passing down your d2 without you even knowing about it, take a piccy

 

[skipup]

Ok will do!

 

[bob the plumber]

another thing skipup, is that i dont know whether you are a customer with basic knowledge or someone who has there g3 unvented ticket and a little bit unsure, but if you are either of the above unvented cylinders arent the sort of thing you want to go playing around with. If you are in any doubt you should always contact somoene qualified with experience to take a good look at it. just like gas, if you get these things wrong at best your going to flood your ceiling or cause a major incident

 

[skipup]

the 22mm pipe is the cold in 22/22/15 T to 15mm gate returns to 22mm d2 pipework. further down in the 2nd picture you can see 22/22/15 tee from the u/v expansion vessel hope this helps i'm stumped?

 

[skipup]

Hi bob, i do have my bpec u/v cert but this arrangement is confusing so i felt it best to gain some advice many thanks.

 

[bob the plumber]

im a bit baffled now skipup, sorry to be a pain but could you put more pics on but from a distance covering all pipe work including tundish and expansion connections. at the moment i can only assume that if that is the d2 pipe im looking at the gate valve is bridging the gap between ch and d2 so to possibly drain off if need be

 

[skipup]

wierd innit? i will try to get you a better view!

 

[skipup]

hope these help Bob Thanks steve?

 

[skipup]

hope this gives a better view thanks Bob ?

 

[skipup]

There does'nt appear to be any drain off point anywhere so i can only assume this cylinder drains through the d2 pipework What do you think?

 

[SimonG]

The gate valve is so that you can drain the cylinder straight through the d2 pipework, without messing on with a hosepipe and drain cock. Bit of nice forward planning, don't know about legality of it though!

 

[bob the plumber]

it certainly looks like a drain off as i mentioned earlier and simon g seems to agree, 95% sure it meets requirements and doesnt break the regs regarding the d2 sorry for the delay in me getting back on the thread i popped out for tea

 

[bob the plumber]

whilst were on unvented cylinders, ill show you my most recent, im quite bloomin chuffed with it and so is the customer
Megaflow Solar Eco 300ltr, external exp vessel, there was a number of heating circs and hot and cold break off's that needed picking up thus the amount of pipe work, tried to make it as neat as poss like always and like i said very chuffed i take pics of my work, bloody love my job

 

[Destroyer2813]

The gate valve is so that you can drain the cylinder straight through the d2 pipework, without messing on with a hosepipe and drain cock. Bit of nice forward planning, don't know about legality of it though!

Im off the same opion

 

[dontknowitall]

Nice work Bob.

Does it work?:ban:

Only joking!

Cracking job and really neat and easy to understand!!!

 

[Gray0689]

It is for a drain off point but would be better being a lever valve

 

[Gray0689]

whilst were on unvented cylinders, ill show you my most recent, im quite bloomin chuffed with it and so is the customer
Megaflow Solar Eco 300ltr, external exp vessel, there was a number of heating circs and hot and cold break off's that needed picking up thus the amount of pipe work, tried to make it as neat as poss like always and like i said very chuffed i take pics of my work, bloody love my job
View attachment 4025View attachment 4026View attachment 4027 View attachment 4028

Looks good mate
But needs lagged

 

[bob the plumber]

Looks good mate
But needs lagged

its a towel cupboard, you wont get any lagging in there

 

[stevetheplumber]

nice job bob having that much space is a luxury normally trying to fit it in a shoe box

 

[Gray0689]

its a towel cupboard, you wont get any lagging in there

Should be lagged 1 metre from the cylinder at least

 

[Gray0689]

Like this

 

[Deleted member 25704]

First situation of gate valve drain off, into d2. I would argue this presents a contravention of water regs. The valve is not high pressure, so risk of leak, which is not visible into d2. In addition, the d2 is piped for the unvented requirement only, so any other discharge into pipe would affect the standing of installation.

I would not be happy doing this, unless I had a tundish, and oversized discharge to take all needs and a 'lock-shield' drain off.

With regard to lagging - any cold water pipework exposed to temperatures above 25 degrees centrigrade must be lagged (water regs). In terms of Part L, then this has been mentioned as within 1m of cylinder - my advice, lag everything.