Y plan system - boiler on 24/7

[eth0]

Hi guys,

I've just moved houses and I've noticed that my boiler (HRM StarFlow: https://web.archive.org/web/20041208234329fw_/http://www.hrmboilers.co.uk:80/pdfs/starflow.pdf) is on 24/7 and it will heat according to it's own temperature regardless if the programmer (Nest) is calling for heat/water. And because the pumps are "closed" and the hot water can't go anywhere, it eventually gets dumped outside, wasting oil to heat the water. The boilers manual says the boiler should be OFF when not heating.

The boiler is pretty simple and has Live, Neutral and Earth - no S/L and P/L. I have no motorised valves and everything is controlled by the Grundfos Pump Plan (http://www.plumbcenter.co.uk/wcssto....all/ti/on/Grundfos_PumpPlan_Installation.pdf). Essentially it's two 15-50's, one for HW the other CH and they only have L, N, E - no switching.

Everything goes in to a wiring center, see attached image or page 8 of the last link. From top left to bottom right:

NO N C          C NO  N        NO  N  C
CYL STAT      ROOM STAT      FROST STAT

PROGRAMMER     CH PUMP     HW PUMP     BOILER
L N HW CW       L N           L  N        L N
      ^ to Nest

So where should I wire my boiler? The Nest controls the pumps so I'm thinking feed the boiler straight from those? If either is activated it will kick the boiler on.

Cheers.

 

[picasso]

Move the boiler live (in the pump plan wiring centre) and put it in the s/l (in the pump plan wiring centre)

 

[picasso]

 

[eth0]

Sorry I should of mentioned I tried that - does nothing. I try and calling for heat/hot water but the boiler just won't come on, even if the pumps are on.

EDIT: I just remembered when I tried that I also removed the loop on the room stat. I've just tried with the room stat and it works - thanks Picasso!