Nest Heatlink only delivering hot water with manual selection.

[RogerE]

Hi - hope someone can help.

In UK. 3rd Gen Nest Thermostat driving central heating (radiators) and hot water. Oil fired boiler. No problems until last week when hot water suddenly started misbehaving. Nothing changed in system.

Heating working perfectly via either thermostat or app. Hot water only working with manual push on heatlink.

Heatlink connected to WiFi and thermostat, all software up to date.

When app or thermostat "ask" for hot water there is a click from the heatlink but it doesn't fire the boiler (although fine with manual).

Have done quick reset and factory reset for heatlink but still no good for hot water via thermostat or app.

Any ideas?

[Frustratedddd]

That's a good one!

Have you checked to make sure you are operating as a system boiler, not just Combi? I assume you are, just checking.

Does the App, show the Thermostat and Hot water icons?

Does the HW icon in the app change to Orange or On, or both?

Check the bacteria is dissabled.

I have come across this, but never been able to work with manual press on the Heat Link.

The HW contactor is the usual issue, but you can use in manual mode, very odd,

Confirm any of those, and see where we go.

[RogerE]

Thanks for the response!

Yes system boiler NOT Combi

App shows both icons

HW in app used to be orange when on - now shows grey while thinking on and causing a click in the heatlink

Bacteria is off

Does that help?

[Frustratedddd]

The app showing grey with the ON in the middle, is a Nest mess up with the software.  You will find after doing a factory reset, the HW icon will be orange for a couple of minutes, then revert to grey. That is normal these days sadly. You will aiso find if JUST hard wired and no wireless between Heat Link and Thermostat, that icon will stay orange. Nest will not alter it because not enough complaints.

However, getting back to your main issue, that's a new one on me.

Can you check terminals 4-6 for power? You only need a neon screwdriver if you have one.

Normal wiring is Terminal 5 is live feed, but with oil boiler you could be different.

Terminal 6 should be no power when not calling, but live when calling.

I'm just wondering if the contactor on the HW side is stuck, and not switching. Doesn't really make sense, as you can manually operate.

[CristianC]

Hey @RogerE,

I'm sorry for the late reply. Did you manage to resolve the issue in the meantime? I'd love to help.

[CristianC]

Hello again. Just checking in. Do you still need my help?

[AlexD]

Hi. Since there has been no reply I will go ahead and lock this thread. 

If there is anything else we can assist make sure to reach out to us on any of our support channels. 

Best regards,

AlexD.