Connecting relay to Firebird oil boiler

You need some help attaching the thermostat to your specific boiler. This way please !
AndrewM
Posts: 11
Joined: 11 Mar 2021, 10:23

Re: Connecting relay to Firebird oil boiler

Post by AndrewM »

Thanks GEORGzer, that’s what I think too.

I’ll keep you posted on what they come back with.

Andrew
AndrewM
Posts: 11
Joined: 11 Mar 2021, 10:23

Re: Connecting relay to Firebird oil boiler

Post by AndrewM »

Still nothing back from Netatmo support from yesterdays email with diagrams.

I've sent them again to photo@netatmo.com for their opinion.



This is what I received from my first contact with Netatmo

Thank you for contacting Netatmo Customer Service.

Yes, unfortunately I confirm, the Netatmo was not designed for electrical systems of this type: switching the coil of a power contactor generates an inductive load while the load switched by the Thermostat must be resistive (power factor: cos phi> 0.8).

Consequently its repair or replacement cannot be done through the warranty.

Thank you for your understanding.




I found this wiring diagram for my boiler online. I can't see any other way to wire my relais to this boiler other than the way I did. Adding a contactor into the circuit should have protected the relais. If the relais is not capable of switching inductive loads then it is not fit for purpose in my opinion. Every boiler will have an inductive load in it, pumps, fans etc.

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GEORGzer
Posts: 2663
Joined: 14 Jan 2014, 18:14

Re: Connecting relay to Firebird oil boiler

Post by GEORGzer »

Well as I wrote before, since your boiler actually has a dedicated „L1“ connector for a thermostat, just connect it to that one directly.
In theory the switch in the Thermostat itself should still work, if you want to try it out.

I guess it is possible that a contactor coil can cause this damage, but I‘m not an electrical engineer.
Home: Weather Station (V3 + Rain & Wind Gauge, 3 additional Indoor Modules, Shield), Valves Starter Pack + 7 Valves, Video Doorbell
Office: Thermostat (V2), Healthy Home Coach, Smoke Alarm, 2 2in1 Sensors

Not a Netatmo employee
AndrewM
Posts: 11
Joined: 11 Mar 2021, 10:23

Re: Connecting relay to Firebird oil boiler

Post by AndrewM »

Thanks GEORGzer,

Just so you know I am an electrician so I'd like to think that I had wired it correctly. I came here for advice because there seems to be a lot of knowledge specifically about Netatmo and I was doubting myself.

The boiler connection is actually live to the high limit first. That live can be from an internal source like a thermostat or timeclock. It just provides switched mains to the boiler. L1 switched live on the diagram above is through the boiler stat and then to the burner itself.

Even if I now wanted to connect straight to the live to the high limit stat, the problem is that the switched contacts in the relais are now fused closed so while the relais lights up when a radiator looks for heat the contacts are actually made permanently. The light just proves the wireless connection is working. The boiler is now live 24/7.

The customer support engineer from Netatmo saying that the relais cannot switch an inductive load I think is wrong. It is surely designed to switch on and off boilers. No matter what way you wire it to any type of boiler the load will be inductive. Every boiler consists of fans, pumps, solenoids etc. Wiring it through the boiler stat will be the same but without the load protection a contactor provides. The relais calls for heat, relais contacts close to the boiler stat, which is already closed because it has dropped below set point and the burner, fans, oil pump and circulating pump run, all inductive loads switched from the relais.

I think that possibly they think I wired the thermostat directly to the contactor. Maybe the thermostat can only switch a resistive load. This is the only thing I can think of.

I really believe my relais is faulty and should be replaced under warranty and instructions sent as to how it should be connected in future.

I'll keep you posted.
AndrewM
Posts: 11
Joined: 11 Mar 2021, 10:23

Re: Connecting relay to Firebird oil boiler

Post by AndrewM »

Update:

I received a response from Netatmo just now.

Thank you for contacting Netatmo Customer Service.

Your electrical installation as it is now, is not compatible with our Thermostat.

Indeed, it was not designed for electrical systems of this type: switching the coil of a power contactor generates an inductive load while the load switched by the Thermostat must be resistive (power factor: cos phi> 0.8).

But you were right not to wire the Netatmo directly to the burner.

However, it is possible to adapt your installation to use our Thermostat.
A bidirectional transil diode (TVS) must be added in parallel of the control wires of the Thermostat.


It appears from this that despite my boiler showing as compatible on the website and nothing in the installation manual about needing to install a diode that I will need a diode for this to work.

I am not happy with this and have written back to Netatmo.

Andrew
AndrewM
Posts: 11
Joined: 11 Mar 2021, 10:23

Re: Connecting relay to Firebird oil boiler

Post by AndrewM »

Update:

I wrote back to Netatmo on Friday afternoon and they have come back to me this morning having agreed to replace my thermostat under warranty.

I will need to wire a diode in parallel so that the relay is protected in future.

Once I have the diode specification I will post the details on here in case that it will be of use to someone else in my position.

Thanks GEORGzer for your assistance on this.

Andrew
GEORGzer
Posts: 2663
Joined: 14 Jan 2014, 18:14

Re: Connecting relay to Firebird oil boiler

Post by GEORGzer »

Glad it worked out for you 👍
Home: Weather Station (V3 + Rain & Wind Gauge, 3 additional Indoor Modules, Shield), Valves Starter Pack + 7 Valves, Video Doorbell
Office: Thermostat (V2), Healthy Home Coach, Smoke Alarm, 2 2in1 Sensors

Not a Netatmo employee
Pedro1865
Posts: 1
Joined: 11 May 2022, 15:22

Re: Connecting relay to Firebird oil boiler

Post by Pedro1865 »

AndrewM wrote: 15 Mar 2021, 11:59 Update:

I wrote back to Netatmo on Friday afternoon and they have come back to me this morning having agreed to replace my thermostat under warranty.

I will need to wire a diode in parallel so that the relay is protected in future.

Once I have the diode specification I will post the details on here in case that it will be of use to someone else in my position.

Thanks GEORGzer for your assistance on this.

Andrew
Did you ever get around to fitting a diode?

I am in a similar pickle (trying to control a 25A contactor to switch on boiler and circluation pump) and it looks like I need to fit a diode so would be very grateful if you can let us know the specification.

Thanks in advance!

Peter
AndrewM
Posts: 11
Joined: 11 Mar 2021, 10:23

Re: Connecting relay to Firebird oil boiler

Post by AndrewM »

Hi Peter,

I fitted a diode as per spec from Netatmo. Unfortunately this didn’t work either and the relay is still permanently closed even when not calling for heat.

I went back to Netatmo and didn’t get any satisfaction so I had to wire the old time clock in circuit to keep the pump and boiler from being permanently live. Not ideal but better than nothing.

Interestingly Netatmo have removed my boiler from their website so I’d say that proves it was never compatible with my setup despite them saying a diode would protect the relay.

I’d say you need some sort of electronic non inductive switch to be switched by the relay and that then switches your contactor. I haven’t looked into it as I am stuck with the faulty relay and won’t pay for another.

Best of luck with it!!

Andrew
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