Worcester Bosch wiring advise please

[J.C.E]

A mate of mine asked me to look at the wiring of a boiler in a flat he is doing up.

As I told him- I am hopeless with central heating.

the boiler is a WB- guessing a combi because there is only a boiler and room stat-no tank, cyl stat etc.
the rads have 'trv's' on them- not sure what these actually are- just know their there lol!

the boiler has a L,N,E from a 5a spur and then there a 3core flex coming out of it that has just been cut.

the Honeywell room stat is in the lounge the other side of the wall.

do I just need to connect the L and N from that 3core to the r.stat?
maybe before it was cut the earth was used as a live conductor too? (Wrong I know...)

any ideas will be great

joe

 

[Traineenoob]

Hi mate really easy!!

L N E from fcu to boiler... Then from Ls on boiler to roomstat then return from roomstat back into Lr on boiler. Roomstat will require a N.

Possible to wire a 5 core flex into boiler and run roomstat cable into the fused connection unit.

 

[Geordie Spark]

A mate of mine asked me to look at the wiring of a boiler in a flat he is doing up.

As I told him- I am hopeless with central heating.

the boiler is a WB- guessing a combi because there is only a boiler and room stat-no tank, cyl stat etc.
the rads have 'trv's' on them- not sure what these actually are- just know their there lol!

the boiler has a L,N,E from a 5a spur and then there a 3core flex coming out of it that has just been cut.

the Honeywell room stat is in the lounge the other side of the wall.

do I just need to connect the L and N from that 3core to the r.stat?
maybe before it was cut the earth was used as a live conductor too? (Wrong I know...)

any ideas will be great

joe

Some roomstats only need 2 wire, others need 3 wires.

The difference is the 2 wire stat is electronic and is very sensitive to temp. changes so the 2 wires are Perm. live (from boiler) and Switched live back to boiler to fire it when stat calls for heat.

The 3 wire stat is mechanical and has a heater (called an Anticipator) inside it to improve its sensitivity and this needs the perm. live, the switched live AND a neutral for the anticipator. It can work without the neutral but you'll get ridiculous variations in room temperature.

 

[J.C.E]

Hi mate really easy!!

L N E from fcu to boiler... Then from Ls on boiler to roomstat then return from roomstat back into Lr on boiler. Roomstat will require a N.

Possible to wire a 5 core flex into boiler and run roomstat cable into the fused connection unit.

What numbers do i use on rstat? For L SL and N?

 

[davesparks]

It depends on the particular roomstat, it will have wiring diagram inside the lid to help you out

 

[J.C.E]

It depends on the particular roomstat, it will have wiring diagram inside the lid to help you out

Honeywell t6360

n in 2 not sure where ls and lr go...

 

[davesparks]

As I said, look at the diagram in the lid, or else look for the wiring diagram online

 

[J.C.E]

Bingo

n 2
ls 4
lr 3

 

[UNG]

All the Worcester Bosch wiring diagrams you could ever need are here

 

[Corbs]

Bingo

n 2
ls 4
lr 3

your wrong there with the live's 1 is ls and 3 is lr

and there very easy to wire, you will be fine just dont over tighten the pcb terminals i have had a few from the factory snap/ fall out bad solder joint

 

[Geordie Spark]

your wrong there with the live's 1 is ls and 3 is lr

and there very easy to wire, you will be fine just dont over tighten the pcb terminals i have had a few from the factory snap/ fall out bad solder joint

He didn't do too bad there ....... one out of three.