s plan heating system with pump in boiler not out side what do i do ?????

[lukesparky123]

Iv done a few heating systems now but no where near an expert yet but im a bit stuck because all the s plan systems iv done in the past have an external pump but this system is a vaillant boiler with an internal pump. So just need to know how to alter the wiring from external pump to internal.

any help would be great.
thanks alot luke​

 

[Guest123]

If the pump is internal to the boiler then a 4core cable may be required as some makes require a permanent live for a pump overrun.

That's about it really, a little bit less work.

 

[truckster]

Depends on the boiler, check the instructions but generally you need a permanent live, switched live,neutral and earth. Some boilers will have a low voltage output for the external controls so you could possibly need five cores so check before putting in any cabling if it will be buried etc.

 

[lukesparky123]

the boiler is a vaillant eco tec and the connections are L N E and then 3 and 4 with a link cable between them. If anyone has got a diagram of what to do would be great i just need to know the difference between what i would normaly do for an s plan system and now with this new boiler
thanks alot
luke

 

[mark80]

Well are there no wiring diagrams with the boiler? Like truckster says id personally throw a 5 core over. Even if you have a spare cores it may come in handy in the future. Instead of taking a 3 core flex to the stand alone pump as you normally do, all you will be doing is essentially using a single live core (from the 5 core flex) to the internal pump. You dont need a seperate neutral and cpc for the pump as these will be linked within the boiler itself with the feed neutral and cpc.

 

[Guest123]

Firstly connect up L,N & E as normal.

Connect the switched live output from the wiring centre (4th core of cable to boiler) to terminal 4 at the boiler, remove the link & discard.

 

[truckster]

Beat me to it Lenny

 

[lukesparky123]

so how i under stand it is i take a single core cable from connection 4 with in the boiler and wire it to both the orange wires from the htg zone valve and the ch zone valve like you would if you was wireing up an external pump ????

 

[truckster]

You got it