Nest Heat link not switching hot water

[matteomacchi92]

Good morning, I hope someone can help me. Yesterday I installed a nest learning thermostat to an existing s-plan system, however I am having issues with the hot water. The heating is working correctly but the hot water terminals aren’t switching. Continuity between terminals 5 and the normally closed terminal, and no continuity to NO terminal even when hot water switched on. Any ideas? 
Many thanks 

[Frustratedddd]

Can you uploadf a picture of the heat link Connections?

Have you put a link between terms 2 &5?

[matteomacchi92]

I haven’t got a picture at hand however the connection are definitely correct. And yes there’s link between L-2-5.

I do have 240V on all common connections and on NC 

[Frustratedddd]

Yes that is the correct link, and from what you are saying the contact could be faulty.

OK, if the wiring is correct, you can easily test with a neon screwdriver if you have one?

You may have done this, but give it a go. Test with no calling for H/W term 4, this should be live - Term 5 should be live obviously, Term 6 no power. Then call for H/W and Term 4 & 6 will reverse.

Should that not happen, then looks like the relay is faulty.

I'm sure you have proved that, but just to confirm.

Oh, just thought, do this with the Heat Link button not the stat.

[DragosC]

Hi there @matteomacchi92.

Thanks for letting me know. I'm sorry to hear that, we know how this can be. No worries. Help's on the way. Just one question. When you mean normally close and normally open terminals, you mean the 4 and 6 terminals on the Heat Link? 

[matteomacchi92]

Yes correct. The issue is with the hot water side only. Replacement nest on its way. 

[DragosC]

That's great. Thanks for letting us know. Should anything else come up, please open another thread and we'll take it from there. Have a good one and stay safe!