Nest thermostat says hot water on but boiler not firing up

[richie_20]

Hi, my thermostat has been working fine previously, but today the hot water is no longer triggering the boiler to heat when activated. The heating however still works. Any help would be appreciated.

Thanks 

[shirem]

I have exactly the same problem!!  i'm having to put it on manual which means my heating comes on when I don't need it

[richie_20]

I explained the problem to a heating engineer this weekend and he thinks my hot water zone valve may need replacing, hoping to get it looked at this week. Will let you know if this works

[Markjosephp]

Hello folks,

I'm sorry to hear you're having issues activating your heater with your Nest Thermostats. Let's see what's going on.

Could you please tell us which Nest Thermostat model you have? From what country are you posting? Also, please check your thermostat's power readouts in its "Technical Info" settings.

I'll look forward to your response.

Thanks,

Mark

[Markjosephp]

Hello there,

I wanted to see if you still needed help. Please let us know if you have any other questions or concerns.

Thanks,

Mark

[shirem]

Hi Mark

Apologies for the delay in replying.  I contacted the Nest support team who took me through some tests and it's something to do with the Head Link not communicating with the boiler - the thermostat is communicating with the heat link.  I'm currently waiting for my plumber to come and sort it as it could be a couple of things apparently - the wiring is S-type, so that's correct for the thermostat.

I'm in the UK - the thermostat model says Display-3.7.  I can't find the power readout - when I click on "data" it takes me to Google FAQs not anything to do with my thermostat.

Any thoughts welcome as I'm not hugely confident in my plumber's ability to sort given that he is not familiar with Nest thermostats!!

Thanks

Shirena

[richie_20]

Hi Mark, similar situation for me, I am waiting for my plumber to come to see why the boiler is not firing up 

[AlexD]

Hi there @shirem . When your installer comes over if possible you can reach out to us. We can help them with anything related to the Heat Link and our thermostat if needed. 
 

Hi @richie_20 . There is something we can do to test the relays. Stand next to the Heat Link with the Nest app and select the hot water control section. Tap in the upper right corner on the cogwheel icon to go into the settings. Take note of the first option you see there and let me know if it is toggled on or off, you can take a screenshot. If it's on, toggle it off during the test.

Now boost the hot water and listen for a clicking noise from the Heat Link. Turn the boost off and listen for a clicking noise again. Once done, go to the heating side and make sure the heating is off, display black. Turn up the temperature until the display goes orange, heating on and listen for a clicking noise. Turn the temperature down until the heat goes off and listen for a clicking noise again. Let me know what the results are and the screenshot from the hot water settings. 

If you didn't get to check these things with my colleagues @shirem , make sure to do these steps as well and let me know. 

[AlexD]

Hi, I wanted to check in. Do you need any further assistance? If so, make sure to let me know. 

[Vladut]

Hey there, I haven't heard from you in a while so I'll be locking this thread. If you have any new issues, updates or just a discussion topic, feel free to start a new thread in the community. Thanks