Central heating - vaillant system boiler

[rick]

A plumber friend of mine has asked for some help wiring up a Vaillant Ecotec system boiler in an S plan configuration. I am familiar with S plan but can’t work out how to do it with this boiler, and the Vaillant manual whilst very good on the gas side is a bit lacking electrically…

The boiler needs L-N-E from the wiring centre, no problem. But then there are terminals 3, 4 and 5 which are labelled “external controls”. I am planning on using the Honeywell wiring centre to make things a bit easier, but unlike a standard boiler, I really can’t see how to wire this boiler up. Planning to have 2 motorised valves, programmer, cylinder stat and room stat.

Also, does the room stat need to be 24v or 230v, or either, have read conflicting things on this.

Has anyone come across similar and could give me some pointers as I am really tearing my hair out on this one!

 

[thebassman]

Hi Rick

You can use a 24v or 230 room stat, terminals 3 and 4 should have a link attached this is the boiler control circuit, terminal 5 is a neutral connection. You connect your programmer switch connections to terminals 3 (LiveOut) and 4 (switched live) Page 29 Fig 4.15. 3 of the manual shows how to connect external controls to boiler.
Hope this helps

Danny

 

[thebassman]

Hi Again

Forgot to say in my last post i would take supply from swich fused spur to the boiler L N E first as boiler needs permanent supply and supply your wiring centre from 3 Live out and 5 Neutral and of course and earth, then terminal 4 is the live in to the boiler. Should be simple to work out valve controls the honeywell web site has s and y plan wiring diagrams.
Danny

 

[Guest123]

We have central heating diagrams here......

http://www.electriciansforums.net/e...cal-forum/11718-central-heating-diagrams.html


Personally I would take my supply direct to a fused spur adjacent to the wiring centre and then wire all valves, stats, pump & boiler back to here.

 

[rick]

Thanks guys, did the job today and all went well. Cheers.

 

[bramboy]

We have central heating diagrams here......

http://www.electriciansforums.net/e...cal-forum/11718-central-heating-diagrams.html


Personally I would take my supply direct to a fused spur adjacent to the wiring centre and then wire all valves, stats, pump & boiler back to here.

As mentioned spur is meant to feed boiler and all external wiring fed from 3,4 and 5 connections. good practice thou to have local isolation adjacent to wiring centre controls.

 

[Harley]

I find the honeywell ST9001S a very good match to the Vailliant ecoTEC

 

[ringer]

I find the honeywell ST9001S a very good match to the Vailliant ecoTEC

That depends on the application. S types are most suitable for landlords or people who like to keep a keen eye on service intervals. It is also only a one-day device. For most people I would have thought a 7 day timer such as the ST9400C would be appropriate.