Hot water not turning on

[AMAK]

Hot water not turning on on its own. It works with the central heating. We have had 2 plumbers who visited us and checked. They both confirmed that the valves are working. For some reason nest doesn't turn the heater on.

I can hear the clicks at the heat link, sometimes,  but not always, when I turn the hot water on.

Tried restarting the heat link when boosting is on on the app. It seemed to work for few days but now that technic stopped working as well. Please advise

[AMAK]

Just to add that, hot water works on the manual mode

[maedacortez]

Hi AMAK ,

Thanks for reaching out! I understand the hot water isn't turning on, and you've already tried some workarounds that aren't working anymore. I'm happy to help! Before we continue, I need to ask a few questions to better understand the situation:

• What type of thermostat do you have?

• What's the status of the Heat Link's LED light?

• Have there been any power outages recently?

• Does the display show a water droplet inside a circle?

I'll be waiting for your response.

Regards,

Manuel

[AMAK]

Hi Manuel

Nest 3rd gen

No power outages

LED is green always

Did you mean water droplet on the thermostat display? Yes there is an orange droplet display

[maedacortez]

Hi AMAK,

Thanks for your reply. Just to confirm what you mentioned that the hot water only works in manual mode I have a question for you: when you tried to disable manual mode, did you press the Heat Link button once?

I look forward to your response.

Regards,

Manuel

[AMAK]

Hi Manuel

Yes, i disable it by pressing the switch once

[Bradley7]

Hi AMAK,

I'm having a similar issue with HW. I have a gas CH/HW system and cannot get HW to turn on via the NEST thermostat or the App. The way the systems work is that if the motorised valve to the HW cylinder is in the open state (it is usually in this as it's default resting state) then, when the CH is turned on, some hot water from the CH will get to the HW cylinder, even though the HW was not specifically asked for.  This is relevant to you because when you press the Heatlink manual button it turns on both CH and HW and  just because in your case this makes some HW it does NOT mean that the heatlink is connecting correctly with the HW - it may be that the heatlink is turning on the CH and making some HW as a byproduct because the valve to the HW remains open. 

It is probably worth investigating the motorised valve that controls the HW since these are a common problem - the valve heads are possible to replace without having to drain the system or doing any plumbing per se and it is a DIY job if you know what you are doing. The electrics can be a bit complicated so ask an electrician if you are not happy doing some basic wiring jobs. There are some YT videos showing the steps. A replacement Honeywell motorised valve powerhead cost me £75 and a 5 way plug makes the wiring simpler so you can avoid getting the control box wires mixed up - again YT covers this - https://www.youtube.com/watch?v=_bkgVQoTd8w 

[Bradley7]

Hi again AMAK - I re-read your original message and saw that you have had some plumbers check the control valves already. I guess that makes it unlikely that the valves are a problem for you. I would ask an electrician to check the valve wiring and maybe specifically check that the power to the valves is working. The control valves also have a microswitch in that controls the boiler and pump being turned on - the final step that makes the HW run. An electrician could check that the microswitch does in fact send a signal to the boiler.

If that is all correct then it must be the NEST /Heatlink causing the problem. 

In my case I'm a bit stuck waiting for advice from Google and when I look via the Google store they seems to sell v3 Nest at present. They stopped supporting V1 and V2 Nest recently too. I have the work around of using CH to make HW but if things aren't sorted soon I'm going to look for a new thermostat and say goodbye to NEST and Google.

[AMAK]

Many thanks Bradley7.

Much appreciated.

Didn't know about the microswitch. That's worth looking into I think. Will get an electrician to check it out.

I wish I could send a video of the sound I hear from near the cylinder, through this forum, when hot water is scheduled to turn on. Our plumber said that is the motorised valve trying to do its job but the boiler wouldn't turn on.