Nest 3rd Gen Thermostat not linking to heatlink - CONNECTIVITY

[PMLW]

Having difficulties controlling the heating using the thermostat:

Works fine if I set the water and heating schedules via my app - boiler fires up no problem

If the schedule is not calling for heat then normally I would turn the dial up on the thermostat but - it doesn't fire up 100% of the time. Sometimes it works but mainly it doesn't.  Once the scheduled heating time has completed then the thermostat WILL turn the heating back on.

I can use the heatlink to activate the boiler at anytime without any difficulty. 

Have reset the thermostat but no improvement.

Any ideas?

[Paul_R]

Hi there @PMLW. I'm sorry to hear about this, but I'll do my best to help. Could you please tell me if you have tried to turn the heating on, or boost the how water from the thermostat? And is the boiler starting fine that way? Also, could you please try to turn the heat on, or boost hot water from the app, and listen if the Heat Link is making a clicking sound when you do it?

[PMLW]

Hi Paul R

Thanks for the reply. 

The boiler always activated ok if the schedule is set for it but if the schedule doesn’t call for the heating and I choose to set a higher temp on the thermostat then it does not always activate. It work sometimes and other times not.

If I go to the heatlink and use that when the thermostat doesn’t activate then yes the boiler activates and I also hear a click etc on the app. 

Thanks 

[LarisaL]

Did you notice any messages or codes on the thermostat display or in the app? Also, what's the color of the light on the Heat Link?

[PMLW]

No error messages. Heatlink green

[TudorL]

Okay, have you noticed any patterns in this issue? Or the activation is random? 

[PMLW]

Good question- mainly when the heating schedule is not active. I.e when the heating has been dormant 

[TudorL]

Got it. By any chance, is the True Radiant feature on? You can check this in the Nest app Settings or if you go to the thermostat display, access Settings -> Nest Sense -> True Radiant and check its status there. 

[PMLW]

Hi. Thanks for the help. Currently at off. Leave it or switch to on??

[AlexD]

You can decide if you want it on or off. You can read more details on what it does on our True Radiant page here. 

I see you mentioned you have hot water control as well. Just to check, is the hot water scheduled to be on during the times where your heating is also scheduled to be on?

[PMLW]

No they scheduled at different times. 

What impact tho does the radiant have on my variable thermostat control?

[LarisaL]

Hi there! The True Radiant feature can turn heating on early to help your home warm to a scheduled temperature on time, and turn it off early to help prevent overshooting the target temperature. 

[LarisaL]

Hi there, just checking in! Did you see the previous message?

[PMLW]

I did but I’m still not clear how it helps me when I walk upto the thermostat, turn it on and the boiler doesn’t always activate??

[AlexD]

It is unlikely to influence it but it's best to eliminate as many variables as possible. 

We want to do some tests to see how the relays in the Heat Link behave. Go next to the Heat Link and open the Nest app on a mobile device:

Heating side. 

1. Select your thermostat to access the heating controls and make sure the screen is black, heating is off.
2. Turn up the temperature until the display goes orange, heating on, and listen for a clicking noise.
3. Turn the temperature back down until the display is black again, heating off, and listen for a clicking noise again.

Hot water side.

1. Go to the Nest app and select the hot water control.
2. Tap on the cogwheel in the upper right corner to go into the hot water settings and toggle the first option there off. This will turn off the hot water schedule, you can enable it back after the test.
3. Boost the hot water for any amount of time and listen for a clicking noise.
4. Turn the boost off and listen for a clicking noise again.

Let us know what the results are.

[PMLW]

Hi AlexD

yes - when the thermostat is “dead” I got those clicking noises by using my phone. 

[LarisaL]

Hi there! In this situation, a continuity test is needed to determine if the relay inside the Heat Link is faulty or the issue is related to another part of your heating system. For the continuity test you'll need an installer/electrician with a multimeter so they can perform the test. I suggest you reach us via one of our live support lines (chat or phone), while the installer/electrician is on site so we can perform the test together and document the results. 

[Vladut]

Hi there, just checking in with you. Did you manage to check my colleague's last message?

[Vladut]

Hi there, just checking in with you. Did you manage to check the last message my colleague sent?

[PMLW]

I did thanks. Noted 😀

[Vladut]

Great. Let us know if you need anything else. I'm one message away!

[Vladut]

Hi there, just checking in with you. Do you still need help?