Additional port valve

[Rockomuir]

Evening all,

Just after a bit of guidance as heating systems are not my strongest.

Turned up to a job which has a green star 30si combo boiler. The boiler was controlled by 3 wire wired r/stat. The electrician before me installed a two zone uhf In new extension with two neostats. There was a wiring centre in the extension with a port valve which meant that the house Ch could work indepently from the uhf. However when the under floor heating Was turned on the house radiators also warmed up.

A new zone valve needs to be added close to the boiler. Is it possible to wire in a separate valve using the terminals in the boiler. At the moment Ls and LR are being used for the r/stat for the radiators and Lr is also being used when the ufh calls for heat.

If someone could point in the right direction or a link to wiring diagram it would be most appreciated.

 

[Leesparkykent]

Add a little wiring centre in by the new valve/boiler. Take the thermostat cable for existing rads into wiring centre, take the valve cable in to wiring centre and take a 4 core flex from wiring centre to boiler. In the boiler connect brown to LS, black sleeved brown to LR, grey sleeved blue to NS, and green and yellow to earth.

In wiring centre connect brown from 4 core flex to grey of the valve and L of the thermostat.

Connect black sleeved brown of the 4 core flex to orange of the valve.

Connect grey sleeved blue of the four core flex to blue of the valve and neutral of the thermostat.

Connect the switched line of the thermostat to brown of the valve.

Connect all green and yellows/CPC’s together.

 

[Rockomuir]

Thank you very much, top answer. Will let you know how it goes

 

[PEG]

.....Please tell us that when you turn the stat up...the toilet flushes

 

[littlespark]

If that’s not a step by step guide, I don’t know what is.

 

[Leesparkykent]

If that’s not a step by step guide, I don’t know what is.

He’s a sparks who’s been a member since 2010....not a DIY’er and this is their 1st post.

 

[littlespark]

He’s a sparks who’s been a member since 2010....not a DIY’er and this is their 1st post.

Yeh I know. That’s why I ended my post with a silly face

 

[Rockomuir]

Hi there,
Thanks for the help. All working nicely. If I could pick your brains again. I have got a feeling that I am going to have to add a two channel programmer to independtly control ufh and the rads. Would I just treat it like a switch that splits the switch live with it’s own L/n supply to power the programmer
It may sound pretty silly me asking but my apprenticeship was doing new builds with simple heating controls and I learnt more about motors than y or a plan heating systems at college.