boiler connections

[diditrain]

Hi all, have got to connect up a Y plan central heating system. The diagram seems pretty straighforward but i am a bit unsure about the boiler connections.
i opened up the boiler and there is an: LS, LR and L for connecting a live. LS and LR are joined with a link.
Can anyone tell me where to connect my live to.

Many thank`s

 

[mark80]

Depends on the boiler, is it a combi or back boiler? what make is it? the boilers I normally deal with you take the link out and its just a permanant L - N - E and then a switch live to the boiler. Have you not got the manufacturers instructions to look at?

 

[dinga1978]

Hi all, have got to connect up a Y plan central heating system. The diagram seems pretty straighforward but i am a bit unsure about the boiler connections.
i opened up the boiler and there is an: LS, LR and L for connecting a live. LS and LR are joined with a link.
Can anyone tell me where to connect my live to.

Many thank`s

hi there, the L is live, the LR AND LS are usually for a room stat

 

[diditrain]

Hi guys i am quite ****ed so excuse my reply, the system has a roomstat and seperate timeclock side by side. I was just unsure about wether to connect my live to Live, LR OR LS and to leave the link between ls and lr

 

[dinga1978]

you ll need to take a five core to the boiler i think connect Lto live and LR,LS back to the roomstat connections on the wiring centre plus N AND EARTH, YOU WILL HAVE TO REMOVE THE LINK.

 

[diditrain]

The boiler is not a combi. The plumber told me that the sytem set up is known as a Y plan.
There is a cylinder, cylinder stat and a mid position three port valve. When i look at the wiring diagram there will be a live returning from the mid position valve, through the connections in the joint box and back down to the boiler. Like i said previously where will i connect this live to? Does it just go to the terminal marked L on the boiler and do i leave LS and LR linked

Hi dinga1978, if you look at a Y plan wiring diagram you see one live going to the boiler

 

[Blueflash]

L= Live input
LS= Live supply to remote stat (for integral programmer)
LR= Live return from stat (for integral programmer)

For external programmer + wiring centre LS+LR need to be joined. All design done in wiring centre.

External programmer input > 5 cores to wiring centre (L, N, E, DHW LIVE, HW LIVE) > room stat+tank stat > 3 port valve > boiler + pump

http://www.tlc-direct.co.uk/Technical/DataSheets/Horstmann/Pics.pdf

 

[diditrain]

Cheers Blueflash, so i just connect my returning live to L inside the boiler and leave the link in LS and LR.

 

[Ridgey88]

No....

if the boiler requires a pernament live then the connections will be as follows.

L = Pernament live
N = Neutral
E = cpc

remove the link !! and connect the switch live to LR this is the same wire connected to the orange wire on the 3 port valve.

 

[hasel5]

boiler is probablys a bosch worcester so connect a perm live to ls and the control live to lr
and remove link

 

[NoSparks]

No, No, NO.

Blueflash has it right. I will modify it slightly

L= Live input This must be a permanent live.
LS= Switcched Live supply OUT to remote stat and or controller.
LR= Switch Live Return from stat or remote controller Otherwaise known as the Heat Demand
N = neutral as normal
E = CPC as normal

If you have a remote pump then also there are lines for

Pump live out
Pump nutral

You do NOT connect a permanent live to LS. This is a switched live from the boiler, the boiler switch will switch this on and off. You must use this for your control gear otherwise a service enginear may switch off at the boiler and expect the control gear to be dead.

If your pump is seperate you MUST use the pump live from the boiler. Many modern boilers have a pump override, ie the pump continues working after the boiler has shut down. This is to prevent the heat exchanger from overheating by maintining water circulation until the heat exchanger has cooled to a suitable level. If you are using a three port valve then there will always be a water flow so you need not worry about a bypass, if ever you use two zone valves (plan S) - or just a sinlge some valve for heating only - the zone valve(s) can (both) shut off, so then your plumber will need to ensure a water bypass as well (often the bathroom towel rail).

 

[thepurple1]

the cables you connect in to LS and LR Will need to be Volt free. make sure there is no voltage on these cables. the voltage comes from the boiler and and is switched via your room stat

 

[Blueflash]

No, No, NO.

Blueflash has it right. I will modify it slightly

L= Live input This must be a permanent live.
LS= Switcched Live supply OUT to remote stat and or controller.
LR= Switch Live Return from stat or remote controller Otherwaise known as the Heat Demand
N = neutral as normal
E = CPC as normal

If you have a remote pump then also there are lines for

Pump live out
Pump nutral

You do NOT connect a permanent live to LS. This is a switched live from the boiler, the boiler switch will switch this on and off. You must use this for your control gear otherwise a service enginear may switch off at the boiler and expect the control gear to be dead.

If your pump is seperate you MUST use the pump live from the boiler. Many modern boilers have a pump override, ie the pump continues working after the boiler has shut down. This is to prevent the heat exchanger from overheating by maintining water circulation until the heat exchanger has cooled to a suitable level. If you are using a three port valve then there will always be a water flow so you need not worry about a bypass, if ever you use two zone valves (plan S) - or just a sinlge some valve for heating only - the zone valve(s) can (both) shut off, so then your plumber will need to ensure a water bypass as well (often the bathroom towel rail).

Just to add to that thorough explaination. On an S plan if both "lives" are "lost" via the zone valves, boiler will stop as its the only supply on an S Plan/Y plan (although you can configure to use a live feed from "white" valve wire on two port valves.) Usually orange wire. I think the plumbing regs now say no open rads just a dedicated flow to return bypass in pipework.

 

[skirby]

You may find this link to some more explainations and diagrams about boiler connections useful:
Central Heating Boiler Electrical Wiring Connection Diagrams for Electricians | Electrician's Blog

 

[Amp David]

Blimey I hope hes not still trying to wire this boiler up:censored:

Not a bad link though