Nest e and Oil Burner

bonobos

Looking for some help/advice on installing a Nest e and Heat Link.

I currently have an oil burner in the shed (about 20ft from house). There is a thermostat sitting on the oil burner.

Oil Burner: Firebird Enviromax C26
Thermostat: IMIT TLSC 07050

The oil burner heats the radiators and the water. There's a separate immersion switch too in the house (used occasionally in the summer).

Power to the oil burner is controlled in the house using a Siemens RWB27. This is wired with 3 wires (Brown/Live, Blue/Neutral, Earth) and is basically an on/off switch for the heating.

I've tried to replace the Siemens controller with the Heat Link by connecting Neutral -> C(common), and Live -> NO(normally open).

The Nest and Heat Link both talk to each other after installation (I can hear the relay in the Heat Link when the dial is turned), but the burner never turns on in the shed.

Is this the right approach for this system? Or, does the thermostat on the oil burner affect things?

bonobos

Is there anyone out there with any idea where the fault lies with this approach...?

You have made a mistake with your wiring.
You should have it like this.
If I recall correctly the terminals on the heat link are tiny so very hard to get two cables into them so make sure your connections are tight.

bonobos

BrownFinger wrote: »

You should have it like this.

Did you mean to include something there? I can't see any images or connections..

bonobos

bonobos wrote: »

Did you mean to include something there? I can't see any images or connections..

Strange I can ,
here it is again.

bonobos

I can see it now, thanks!

So the live feed goes to both the NO, and C terminals on the Heatlink e?

bonobos

bonobos wrote: »

I can see it now, thanks!

So the live feed goes to both the NO, and C terminals on the Heatlink e?

The C in the input and NO is the output.
The live feeds into C, when the rely closes the NO (normally open) becomes live and switches the boiler on.
The L & N are the power for the heatlink itsself.

bonobos

I can't attach images or drawings to this thread. Not sure if that's because I've just joined.

Anyway... I can't wire it the way you've suggested, because the Live/Neutral feed terminates on the old controller in the house (where I want to place the Heatlink). So, I can't break the live feed so it can be switched using the relay. The power feed just hangs from the wall when the current controller is removed.

Does this make sense?

bonobos

bonobos wrote: »

Does this make sense?

Not really,
Stick your pics up on postimages.org and link to it.

zg3409

bonobos wrote: »

I can't attach images or drawings to this thread. Not sure if that's because I've just joined.

Anyway... I can't wire it the way you've suggested, because the Live/Neutral feed terminates on the old controller in the house (where I want to place the Heatlink). So, I can't break the live feed so it can be switched using the relay. The power feed just hangs from the wall when the current controller is removed.

Does this make sense?

I recommend you get an electrician as you don't seem to know what you are doing and there is a risk you might wire up wrong and say the earth of the boiler might become live. It could make every radiator and tap in the house live.

Assuming you want to risk it, .... can you take a photo of wiring in house?
Did you make a note or photo of how it was wired before in terms of the Siemens rwb 27 timer?

Be careful, often wire colours are not as you expect. Sometimes electrician use the earth wire for live and blue for live and sleeved earth for live. This is particularly true in these cases. Ideally there would be one cable providing power in and a different cable providing power to boiler but often short cuts are taken and timers are installed later in time.

If you had the old wiring photo it should be relatively easy to show which wire (no matter colour) goes to the new 'timer'

WestWicklow1

bonobos wrote: »

I can see it now, thanks!

So the live feed goes to both the NO, and C terminals on the Heatlink e?

No, based on the drawing, the live feed goes to L and C. A separate live comes from NO to the boiler. NO will be switched on and off by the relay to turn the boiler on and off.

bonobos

I haven't permanently modified anything yet, and I'd be fairly comfortable working with the electrics, so I'm trying to hold off getting a sparks in just yet. I took plenty of photos of the current setup.

I tested the Live wire with a phase tester to check that's it's hot and it was, so I'm confident that the Brown wire is live, as expected.

This image shows the block connections that connect to the Siemens controller (with labels for L, and N):
https://postimg.cc/G441f73z

This shows the overview of the boiler in the shed:
https://postimg.cc/Fd7ckQh3

And this shows the wiring for the simple thermostat on the oil burner:
https://postimg.cc/vcMBpdCh

This is view of the circuit shown on the Siemens controller:
https://postimg.cc/KRkNsw30

whizbang

As ZG. suggested, The earth wire is taped and used as live for the boiler.
2 is Common, 4 is NO. 3 is NC (NormallyOpen, NormallyClosed)

Not all that different in heatlink;
Live and Neutral same as Siemens, Link live to common (same as siemens), connect taped earth wire to NO connection.

bonobos

Great, thanks for the help all. I obviously still don't see past the conventional wire colouring, even when the wires are taped to suggest otherwise.

I'll try the following on the Heatlink e:

C: LIVE (brown)
NO: EARTH (taped brown)
FP: N/A

OT1: N/A
OT2: N/A

Neutral wire connected to terminal block supplied with Heatlink.

embraer170

How did it work out?