Drayton LP241 to Nest 3rd Generation

[stem]

Good! You have probably sorted it. Heat link terminals are in a tight space and quite fiddly, even for those of us that have had a bit of practice. It's not uncommon to find a bad connection.

 

[Zee Hyde]

@stem, its been 10 months it was all working perfectly fine so thanks for your initial help.

But from last 1 month I have noticed that heating also turns on with hot water timer so not sure where is the issue.

To clarify heating works as per nest thermostat but it also turns on with hot water times so it seems hot water timer also send signal to heating as well.

I have tried below:

1. Reset Nest
2. Restart Nest few times
3. Pushed cables in heat link and other box.

I did noticed after pushing cables it did got fixed but I might be wrong as it is still happening. Heating stays ON throughout water timings and ignores nest thermostat completely. Like on nest it shows heating is turned off but in actual it is turned on.

Attaching few pictures, can it be related to boiler service as my yearly ervice is due ?

I am really worried as my gas bill is going on roof and house stays extra warm

 

[stem]

If it has been working correctly, then most likely the wiring will be correct. However, if "after pushing cables" things change I would start with checking the connections are secure and that the metal wires and not the outer insulation are in contact with the terminal screws. Having said that, loose wiring usually means things don't work when they should, not the other way around and come on when they shouldn't do.

When the heating stays 'on' when it shouldn't be 'on', is the Heating light on the front of the Nest Heat link lit?

If the light is on, then the problem is with the Nest, or its settings. If the light is going off but the heating remains on the fault is elsewhere.

It won't be the boiler. Its sole task is to produce heated water when requested. The motorised valve and controls switch the boiler 'on' and then direct the aforesaid heated water to the radiators and hot water cylinder as required. It may be that the motorised valve isn't closing the heating port properly when it should, especially if it's a bit stiff after a long summer rest. In which case, when the hot water is operating, water will also go to the radiators as well. With the heating and hot water both 'off' try sliding the manual lever on the side of the motorised valve a few times to see if it frees it.

Unless you are using gallons of hot water constantly, the hot water cylinder should heat up quite quickly say 10-30 minutes depending how cold the water in it is to start with and then the cylinder thermostat will shut it down, so I wouldn't expect it to make much of a difference to your gas consumption and the short on period is unlikely to make the house "extra warm".

Over a forum this sort of thing can be difficult to diagnose. However, the person servicing the boiler should be able to fault find for you quite quickly.

 

[Zee Hyde]

If it has been working correctly, then most likely the wiring will be correct. However, if "after pushing cables" things change I would start with checking the connections are secure and that the metal wires and not the outer insulation are in contact with the terminal screws. Having said that, loose wiring usually means things don't work when they should, not the other way around and come on when they shouldn't do.

When the heating stays 'on' when it shouldn't be 'on', is the Heating light on the front of the Nest Heat link lit?

View attachment 209251
If the light is on, then the problem is with the Nest, or its settings. If the light is going off but the heating remains on the fault is elsewhere.

It won't be the boiler. Its sole task is to produce heated water when requested. The motorised valve and controls switch the boiler 'on' and then direct the aforesaid heated water to the radiators and hot water cylinder as required. It may be that the motorised valve isn't closing the heating port properly when it should, especially if it's a bit stiff after a long summer rest. In which case, when the hot water is operating, water will also go to the radiators as well. With the heating and hot water both 'off' try sliding the manual lever on the side of the motorised valve a few times to see if it frees it.

Unless you are using gallons of hot water constantly, the hot water cylinder should heat up quite quickly say 10-30 minutes depending how cold the water in it is to start with and then the cylinder thermostat will shut it down, so I wouldn't expect it to make much of a difference to your gas consumption and the short on period is unlikely to make the house "extra warm".

Over a forum this sort of thing can be difficult to diagnose. However, the person servicing the boiler should be able to fault find for you quite quickly.

Thanks Stem, currently water is on and heating as well but light on nest is in steady green circle as below:


I think it should show steady green drop sign to show water is turned.

And on mobile nest app it is below:



On nest it is like



On boiler it is like



I tried turning on heating on nest app but it does not change the light status on nest so what do you think issue can be.

If i click center Nest button on Heat link only at that time I see both lights for water and heating.

 

[Zee Hyde]

Another thing I tested, reseted the heat link and than tried to switch ON hot water, i did hear the click sound within heat link and it triggered the boiler to turn on and I also noticed water sign on boiler switched ON. So it looks good but it did not turned on water sign/light on heat link.

I have turned off heating from nest to see if it makes any difference.

 

[Zee Hyde]

Now I noticed the light on boiler also turned off after some time so now I clicked manual on heat link and now I can see lights on heat link and boiler light also turned on for some time now.

It seems issue with heat link to me, any way to rectify ?

 

[stem]

If you're sure it's the Nest and have tried a restart already, the only other thing I can suggest is a full factory reset. This will erase everything and take it back to the condition in which you originally received it. If you want to try it you can find the instructions here.

 

[Zee Hyde]

If you're sure it's the Nest and have tried a restart already, the only other thing I can suggest is a full factory reset. This will erase everything and take it back to the condition in which you originally received it. If you want to try it you can find the instructions here.

Performed reset as per guide and still same, heat link kicks boiler but after few minutes boiler sign for water goes off but nest app still shows that it is switched ON.

I have called out engineer as it seems issue with nest to me.

Thanks as always for your help and guidance,

 

[Zee Hyde]

If you're sure it's the Nest and have tried a restart already, the only other thing I can suggest is a full factory reset. This will erase everything and take it back to the condition in which you originally received it. If you want to try it you can find the instructions here.

Performed reset and it seems to be stable since than will keep it under monitoring

 

[Zee Hyde]

Thanks again as always, really appreciate your help.