Open therm - Is it worth it over the standard switching?

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I recently installed a drayton wiser hub along with a few trvs and room stat.

I noticed that the wiser hub supports opentherm as well and recently seen that my boiler (Ideal Vogue C40) also has support for it.

Would it be worth switching to opentherm?

I understand a slight tweak to the wiring might be needed for this, so would have a few questions around this if it is worth doing.
 
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In theory, yes. Theory is that the Wiser hub knows how much heat is required (from comparing trv setpoints to trv current temperature) to achieve your requirements so it can more precisely control the boiler burn.
In practise, not got enough comparative data but I'm not noticing any massive differences in gas consumption when switching between Opentherm and 'normal' control.
Also note that if you have the multichannel Wiser hub (2 channels heat, 1 hot water) it doesn't officially support Opentherm operation
 
In theory, yes. Theory is that the Wiser hub knows how much heat is required (from comparing trv setpoints to trv current temperature) to achieve your requirements so it can more precisely control the boiler burn.
In practise, not got enough comparative data but I'm not noticing any massive differences in gas consumption when switching between Opentherm and 'normal' control.
Also note that if you have the multichannel Wiser hub (2 channels heat, 1 hot water) it doesn't officially support Opentherm operation

Thanks,

Currently have the single channel kit. Boiler is a combi and only have a sinlge heating zone.

I am running a room thermostat in the main hall and 2 TRVs, I plan to extend TRVs into other rooms at some stage.

I'm assuming the switching between the 'standard' and opentherm switching you are altering the wiring each time?
 
Thanks,

Currently have the single channel kit. Boiler is a combi and only have a sinlge heating zone.

I am running a room thermostat in the main hall and 2 TRVs, I plan to extend TRVs into other rooms at some stage.

I'm assuming the switching between the 'standard' and opentherm switching you are altering the wiring each time?
You should see the benefit then though you may have to adjust some boiler parameters (my Intergas has menu options for how much direct control Opentherm is given)
Correct about the switching- system is not exactly standard (there might be some WiFi relays involved) :)
 
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You should see the benefit then though you may have to adjust some boiler parameters (my Intergas has menu options for how much direct control Opentherm is given)
Correct about the switching- system is not exactly standard (there might be some WiFi relays involved) :)

Is it ok for the drayton and boiler to still be powered from the same fused spur when switching to opentherm?

This is the 4 core cable currently coming into the wiser hub, the grey wire is connected to terminal number 3 on the wiser backplate.

Let me know if this is correct in order to get opentherm to work:

1. Disconnect the grey wire at both ends (wiser backplate and boiler)
2. Connect 2 core cable from the opentherm module into the opentherm terminals within the boiler

1674422028181.png
 
Yes power arrangements are fine.
You only need to disconnect 1 end of the grey (assuming grey is heat on, can't tell from the pic), disconnect at Wiser end for sure.
Yes 2 core from Opentherm block in the Wiser (you'll need a very thin terminal driver and thin cable, think I used 0.5mm 2 core) to Opentherm block in the boiler.
WARNING Do not put 240v anywhere near the Opentherm terminals, it won't like it.
WARNING 2
Check boiler manual- don't know if the wiring cover is part of the room seal, if it is then it's a GSR job.
WARNING 3 Again check the book- there may be links in the boiler that need setting or removing, you may need to enable OT control in the setup menu.
 

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