Wiring a SALUS RT500RF into a Viessmann Vitodens 100???

[stroller133]

I currently have a Sunvic RF Digital, but the receiver is not working any longer - the circuit boards seems to have given up. The signal are still recieved from wireless stat but the switch to the boiler is not working. Even pressing and holding the test button does not work.

Anyway, I have now purchased a SALUS RT500RF as I wanted to have different temp profiles throughout the day as we used to have a Drayton RF3 in our old house, but found them a bit pricey.

I have taken the cover off the Sunvic receiver and have found a Live and neutral conections for 230V supply (L & N) and two wires into 'C' and 'On' I assume these are wired to the thermostat loop of the boiler. The new receiver can be wired 3 ways:
1. 230v Application (link left on receiver)
2. Volt free (Link removed)
3. Wiring into the external Thermostat lop of a boiler.

I think I want to follow 3, (although 2&3 are exactly the same?), but want some re-assurance first. Obviously L and N are direct replacements and will still go L & N on the volt free/external loop diagram. Then I assume the wire that is currently C on sunvic will go to COM on Salus and the wire to ON on Sunvic will be NO on Salus.

Please can someone confirm this, or advise if completely wrong.

Thanks