Hot water not working

[Sgrieves]

Hi - My hot water isn’t working on schedule. It says it’s “on” but the background in the app is still grey.  Also when I boost, again it says “on” but is grey still and there is absolutely no hot water. 

When the immersion is turned on on the hot water tank, and I switch the nest to boost, then and only then the “on” screen glows orange.  I know then that the hot water is working - I think the nest isn’t.  Have done a restart on the control - what more can I do please?  Thanks! 

[emmalavaine]

Hi, no error message & it says the hot water is scheduled 'on' to my timed settings.

[CristianC]

Got it. Can you confirm if the schedule is enabled on the thermostat? You can check it in Settings > Hot Water Schedule
I see that the previous agent recommended a continuity test to be done on the Heat Link. Can you tell me the results? Also, have you tried to reset the thermostat to factory settings?
 

[emmalavaine]

yes the thermostat is scheduled for hot water. I’ve been resetting as below (not sure if this is the same as the factory settings tho);

-mode, settings, reset, schedule, reset, ok

im waiting for an available electrician to check the continuity yet

[AnaM]

Hey @emmalavaine,

My colleague was referring to the factory settings, to reset it like that you need to go in Settings> Reset> All Settings. Please keep in mind that this deletes all your schedules and preferences saved for the thermostat. Also, after factory reset you'll be asked to set up the thermostat again. Let me know if that was tried too.

[emmalavaine]

Hello AnaM,

I did the factory re-set Sunday evening & the water heating has unfortunately stopped working again this morning (Wednesday).  So it looks like this isn't the issue ?  What's next please ?

[LesleyS]

My hot water is not coming on per the schedule. This has just started happening this month. This coincides with the dates mentioned above. Is there one set of instructions that I can follow which will resolve the issue?  I’ve just spent £225 getting the hot water/heating switch changed. If it’s an app issue then this is really annoying and expensive!

[LesleyS]

Just looked at the thermostat i.e. not the app. The hot water schedule had been disabled. Not sure how/why!  I’ve re enabled. Let’s see if that works!

[WA2]

Hi I had the Nest installed few weeks ago and all was working fine until 2 days ago and since then I am facing same issue. When Hot Water on then boiler does not fire at all. Heating is working all ok.

it was all working like a dream until 2 days ago and now struggling to switch on hot Water. Even when I’m heating mode boiler is on and as soon as switch the water it goes off. No change in wiring or anything since installation.

[X5EBR]

Hi, I’m having the same problem… boost not working!!! Torture having to have cold showers in this weather! Can anyone help? I haven’t changed any setting etc, so I don’t understand why the sudden issues. Is there a new software or something? Thank you!! 

[Mel2]

I first had issues on the 31st October- we are still stuck with our hot water not working. We have to press the manual heat link button which puts both heat and hot water on, house becomes a sauna whilst we make sure we have enough hot water to shower. Boost from the thermostat- and it thinks its boosting but it isn't.  We were all fine since March 21 with the nest being installed- boiler is less than three years old and all been checked too. I have done factory resets, reset schedule- had a valve replaced- but not tried motorised valve bit as discussed further up. It's just so infuriating. 

[Poolius]

+1 - I'm also getting these hot water issues. Nest app stays grey even when it says "On".

No hot water most of the time although I've just managed to boost it (with my radiators turned off) and it's worked as a one off but not on the schedule.

Looking at the sheer number of people on this thread with the same issue surely this is a software or firmware bug? Have Google acknowledged this yet? The thread is too long to read every post.

Many thanks

[CristianC]

Hello everyone,

 Sorry for the late reply. The hot water icon turning orange, is an interactive feature. As long as it says "ON" it should be working. Turn on manual mode by pressing on the Nest button on your Heat Link. Check if you have hot water and then turn it off. If the hot water worked in manual mode, try too boost it again. Check if it works with manual mode turned off. Let me know how it goes. 

[Steve59]

You are correct mine works fine when saying “On” but

how hard is it to make the icon turn orange when it is on, I know the boiler may not be calling for heat if the tank is up to temperature OR release a statement from

Google saying it is not meant to turn Orange as Orange means calling for heat and as mentioned above that may not be the case 

[CristianC]

Hey @Steve59. Thanks for getting back to me. I'll take this as a feedback. We're always looking to improve. 

[bodas73]

my app used to do this, it would stay orange all the time as I am letting the water cylinder call the water when needed however I did a reset on the boiler and left switched off for 30 mins., the heatlink and thermometer also did a reset. I cleared the Cache on the app (not the data) and then did a force stop. Now it works as it should. The water is grey but says on (this is when not calling for hotwater) it goes orange and says on when it calls for water. hope this sorts your issue

[Steve59]

I would be impressed if my hot water icon turned orange when calling for heat, but it has never done this, it always stays grey. If anyone know the magic billet to make it turn orange when the boiler is required then do tell

[Simkar]

I thought I was alone with this issue! I have noticed for the first time that my Nest Thermostat shows that my hot water is on but does not glow orange. It is the first time I remember this happening. All I have done is alter the hot water heating schedule slightly to reduce the time my hot water is heated. The schedule shows that the hot water comes on between 6.00am and 8.00am in the morning and 16.00 to 18.00 in the evening. Also my boiler does not seem to be firing up BUT if the hot water temperature in my tank was already virtually hot perhaps the water will not be heated for the whole period set on the thermostat as the ambient temperature was already reached and the orange glow becomes grey again? I did notice that the hot water was orange this morning at 6.00am for a few minutes so this does seem to bear my theory out …

[CristianC]

Hey @Simkar. You have a good point. Even if the hot water is scheduled to be on, the thermostat will stop it if your hot water has reached the flow temperature. 

[Simkar]

Thank you for the recognition - I do hope reading my post will help some people in this thread. By the way, I did telephone NEST this morning and had am IMMEDIATE response on the telephone in an endeavour to help with this issue - I was very impressed with the service but I cant remember the guy’s name! NEST can’t  be trained in all aspects of somebody’s heating and hot water systems, but it has certainly added to the confusion in some of these posts in my opinion.

[CristianC]

I'm glad to hear that. Thanks for your feedback. 

[Simkar]

Hi Cristian C, could I ask will the orange glow come on again at the start of the next scheduled hot water heating period until the flow temperature has been satisfied?

[CristianC]

Hello again. As long as it says on, your hot water should be turned on. The icon won't necessarily turn to orange. 

[Simkar]

Just checked. The icon turned orange after about 4 minutes and the boiler fired up but has since stopped again, the icon remains orange so there must be enough hot water for the thermostat to stop the boiler heating any more … 

[Mel2]

Ours did this on the 31st October- we are drawing a blank- it worked perfectly from installation in March. It will only come on when the boiler is heating- the min themostat reaches desired temp it turns hot water off. If I use boost it will only do it if i have wahcked themostat up high in order to kick in.  We are wasting so much energy by using manual heat link- and obv we need to sort this asap with energy prices rocketing- and approachign spring when we won't use heat but only hot water.. We are beginning to have no choice but to have it uninstalled, and pay for a "new old fashioned system"- which is total utter irony.  The price of the nest, the installation, the plumbers to check and the last 3 months of higher bills, and another fitter to pay for and buy an old thermostat. `This is just absolutely crazy!!!! Google why are you not helping- I have reset all schedules manually, reinstalled 2 times. 

[Rsandon]

Hello, I am facing a similar issue described above where the hot water does not work. When I boost on/off the hot water on the Nest app, I do not hear any click coming from the heat link. The motorised valve is not faulty and if I set it to manual I can get hot water. Anybody any idea what could be? Is it a Nest related issue? Thanks for help.

[DragosC]

Thank you all for your replies. 

Since all of you have similar issues, please take a look at the instructions below:

1. Please check if the schedule for the Hot Water is enabled from your Nest app's settings > Hot water icon > Settings > Hot water schedule, make sure the tick is set to "On"

2. Check if the Bacteria Prevention option is set to OFF. In your Nest Thermostat's settings > Equipment > Continue > Bacteria Prevention. Make sure you press on "Disable" if it's on. While it's off, you should see "Enable"

3. Perform a click test on the Heat Link's relays (Make sure the light at the top is green). Go in front of the Heat Link with the Nest app open. Press on the hot water icon and press on "Boost" for 30 minutes. Let us know if you can hear a click from the Heat Link. Same for turning off the boosting.

4. Please send us a picture of the Heat Link's wiring if it doesn't click, we'll have to take a look at it and see if it's been wired correctly. 

[Rsandon]

Hello, thanks for your reply. I have checked all the settings and they seem ok. I still dont get the click when I turn on the water boost. I took a picture of the wiring as you suggested. Do you see anything wrong with the wiring

 

? Thanks for help

[DragosC]

Hi @Rsandon

We've taken a look at the picture and it seems the terminal 3 is connected with terminal 5. Which makes us state that the Heat Link is miswired.

The wiring should be as follows:

L terminal connected with terminal 2 and terminal 5 as those are the relays and they need power

3 terminal needs to be wired with the switch-live from the heating valve

6 terminal needs to be wired with the switch live from the hot water valve

Please contact an installer to help you with the wiring.

Let me know how it went. 

[Rsandon]

Thank you very much for the reply. I attached another picture where you can see where the wires go. I cannot really tell if terminal 3 is connected to 5. Would it be safe if I just try and swap the wires of terminal 5 and 6? Or is there a risk that I blow up something? 

When I push the button on the heat link, the three leds light up and both heating and hot water start working. Does this mean that wires are somehow correctly wired?  

I also tried to do the continuity tests and the heatlink seems to have no issues with that.

One last question, I noticed that there are no wires going into T1 and T2 on the far right. It that normal? 

 

[DragosC]

Thanks for the explanation @Rsandon

Let me explain this how this works. If you press the manual mode button, the whole system gets energized. However, when the manual mode is off, the 2 and 5 terminals need to receive their power from the L terminal by a loop or a bridge between them. 

Also, it would be for the best to let an electrician check as there are 240 V of power in there and it could also damage the heating system. The power needs to be turned off to the whole system before interacting with it. 

[Rsandon]

Hello, thanks for coming back to me. The wiring is checked and I can confirm that terminal 2 and 5 are receiving power from the terminal L. The wire colors dont match, which makes it more confusing, but 2 and 5 are bridged. Also the continuity test was done and pass. However, when I turn on/off the hot water boost the signal is not received and I cannot hear any click. Do you have any other suggestion on what to check? Thanks for support.

[DragosC]

Hi there @Rsandon . If the continuity test has passed, that's technically impossible. The continuity test shows us whether the relay inside the terminal number 2 or 5 are energized and switching between 1 and 3 or 4 and 6. The continuity test should be done as follows:

Let me know how it went please. 

1. Ensure the relay switch is in the correct position by checking for continuity with feed Live and Neutral connected but all wires disconnected from the relay itself.
   1. When the Nest thermostat is calling for heat, check for:
      1. Continuity between 2 and 3 
         • Yes - Correct
         • No - Incorrect
      2. Continuity between 1 and 2
         • Yes - Incorrect
         • No - Correct
   2. When the thermostat is satisfied, check for:
      1. Continuity between 2 and 3
         • Yes - Incorrect
         • No - Correct
      2. Continuity between 1 and 2
         • Yes - Correct
         • No - Incorrect
   3. When the Nest thermostat is calling for hot water, check for:
      1. Continuity between 5 and 6
         • Yes - Correct
         • No - Incorrect
      2. Continuity between 4 and 5
         • Yes - Incorrect
         • No - Correct
   4. When the thermostat is satisfied, check for:
      1. Continuity between 5 and 6
         • Yes - Incorrect
         • No - Correct
      2. Continuity between 4 and 5
         • Yes - Correct
         • No - Incorrect

[DragosC]

Hi there, I'm just following up on our last message. Do you still need our help? Keep us posted. 

[Rsandon]

Hi. Thanks for following up. Yes it is solved now. It turned out to be a settings issue. I have four thermostats, but the hot water was set to on/off on the wrong thermostat. I had to find out which themostat is connected to the heath link with hot water connection and change settings on that. Irina from customer service really helped on the phone. Thank you for the support.

[Mel2]

I did all of this and can hear the audible click from the heat link - when I boost, or turn it on or off next to the heat link. I still cannot get hot water to come on- it thinks it is boosting, but doesn't actually kick in and do anything. I don't think I should have to look at wiring- why, after working exactly for 6 whole months- did it just stop and then have these problems. Nothing has been re-wired!  I have paid for  a boiler check, an annual boiler service, a new valve. There has to be a glitch that google need to sort surely!???

[DragosC]

Thanks for explaining @Mel2

If the click is heard it means the signal is sent to the boiler. You can check most easily on this by performing a continuity test to the Heat Link's relays with a multimeter. 

[Ryan407]

Sometimes our scheduled hot water doesn't work so we don't bother with that anymore and sometimes the hot water doesn't actually heat up if the heating is on at the same time. It's as though it gives priority to the heating. It causes a lot of stress and occasional arguments... worse than a simple timer as at least that's reliable. Its a shame because it looks great and the concept is great but experience living with it is varied at best.

[buzzard1974]

It certainly looks like a bug where the screen shows grey not orange however the heating still works. I think the issue is we only check this screen when the water is not working for some reason and assume it's this indicator screen bug causing it.

I found that the issue on mine was caused by a faulty motorised valve. The nest calls for hot water and activates the valve which allows water to the tank to heat it. This valve takes about twenty seconds to activate and only when fully open does a second set of contacts get made. This electrical connection is what fires the boiler. My valve was seized and was intermittently working. I removed the head off the valve and freed it up with wd40 and careful use of pliers. I also replaced the motorised head as it was burnt out trying to operate seized valve. 

Problem solved.. hot water but still grey indicator screen. I can live with that.

[CristianC]

Hey there. I'm happy to hear that the issue has been resolved. If anything comes up, let me know. 

[CristianC]

Hello there. I see that the issue has been resolved so I'm going to lock this thread. If anything comes up, feel free to open a new one.