Worchester Greenstar 1000 + extension kit

hace_frio

Hi,

I have a Worchester Greenstar 1000 (GR1000W 24 C NG | GR1000W 30 C NG). There are no instructions in the Tado app about how to wire it to an extension kit. I have found them for the Greenstar 2000, showing how to do the 230V Relay connection.

In the wiring diagram of my boiler (see below) it shows the boiler allows for different connections:

• Low voltage I/Os for controls
• 230 V external controls interface

I have connected the BUS pins of the "Low voltage I/Os for controls" to the + and - in the Extension Kit. This works in therms that when I turned on a radiator thermostat then the heating turned on. When turning all the radiators off, the heating seemed to turn off too (the flame icon disappeared from the display) but the pump kept going (I left it for an hour) so something seemed to be wrong.

After that attempt I connected to the "230 V external controls interface" following the instructions for the Greenstar 2000 and everything works fine, when I turn on/off the radiators then the heating turns on/off too (including the pump).

So my heating works and there is no emergency. However my understanding is that the "Low voltage I/Os for controls" are preferable as they are the digital connection which allows for modulation which is more efficient. Is that right? If so, what can I do to make it work (without the pump staying on)?

I attach a photo of the diagram for electric wiring of my boiler (from the installation manual).
Thanks in advance :)

Craigcowley

I have the same boiler and would like to know the best way to connect as well

policywonk

According to the installation guides this boiler can be controlled through the EMS BUS, with the Greenstar Comfort 2 wireless controller. Now that EMS BUS version is equivalent to what Tado calls the HT BUS protocol.
I suggest you write to Tado sales, point this out and ask for a validated procedure to implement HT BUS on that boiler, giving them a full description of the layout of your system, spelling out:
1 Whether it is used genuinely as a Combi.
2 Whether there are zone valves in place.
3. Identifying all existing thermostats.
4. Setting out what you want to achieve by using Tado.

It is true that the 2000 and 1000 seem to have common logic, but their firmware is different. Make sure the Tado team understand that.
Now if there are obstacles, come back and we will try to help.