Y plan with 6 core and 5 core valves

[Martynrosscampbell]

Hi,
Ive just been to a job to where the plumber has replaced old corroded unvented cylinder with a new megaflow.
Arrive at customers house to be told that the plumber said to tell me its a Y plan! No problem I thought, expecting to see a 3 port and a 2 port for the cylinder.
What I found was a 28mm 6 core zone valve and a 22mm standard zone valve. It looks to me to be plumbed like an S plan. flow from boiler T's then through the 28mm valve to the heating and through the 22mm in to the cylinder.

Untitled

• Martynrosscampbell
• 11 Sep 2013
• 1

picture should give a bit more of an idea.

The plumber doesn't seem to want to answer his phone or return my voicemail, so I thought id ask you lot!

need to know what kind of system this is and hopefully someone could pop me a wiring diagram so I can go and finish it tonight!!

Thanks in advance

 

[twgas]

6 core are wired same as 5 core but the white needs to be made safe as it will be live when the valve is closed.

 

[Martynrosscampbell]

I realise that a 6 core can be used normally without the white but I find it odd that the plumber has specifically told them its a Y plan. and why not just use a standard valve? the 28mm 6 core is obviously more expensive. and must have a job to do!!!

 

[steve32]

You cannot use a y plan valve with an un-vented cylinder.

 

[picasso]

The plumber has used a 28mm zone valve to get the heat to the rads, it will be wired up exactly as a standard s plan and as twgas has said make the white wire safe.

 

[Martynrosscampbell]

great stuff.

so I don't need a connection from the HW off in the programmer and terminal 3 in the cylinder stat??

Thanks again

PS. I still don't understand why he would have installed the larger 28mm valve if its not required?? the pipe work is all 22mm so the valve has got reducers. anyone tell me why?

 

[HERTS P&D]

It's what he had left over from the last job?

Andy

 

[HERTS P&D]

It's what he had left over from the last job?

Andy

 

[Martynrosscampbell]

fair point!

Back to work for me then......

 

[picasso]

The cylinder is supplied with a zone valve, he probably didint have a 22mm for the heating so stuck in a 28,

you can use a 3 port and a two port for unvented cylinders (in reply to steve32)

 

[steve32]

you can use a 3 port and a two port for unvented cylinders (in reply to steve32)

I felt that was too much information for the op

I am G3 registered.

 

[Boilerman2]

I am G3 registered.

Are you sure!!
why state (incorrectly that "Y" plan cannot be used! - of course it can BUT you must fit an additional 2 port valve...how is that too much info??

 

[Martynrosscampbell]

Job done, spoke to the plumber and the customer again and there is some dispute as to who said it was a Y plan. I think it was a slip of the tongue by the plumber!
28mm valve was wrongly supplied by the plumbers merchant!
could of had it done by 3.30 if I knew it was an S plan to start with!

 

[gaspro1981]

I am G3 registered.

Are you sure!!
why state (incorrectly that "Y" plan cannot be used! - of course it can BUT you must fit an additional 2 port valve...how is that too much info??

Are you sure boilerman2

 

[MJGas]

Is the plumber G3 registered, Just ask him about the D2 pipe from the tundish