I've traced the wiring and it's here:
I don't understand the thing with the two black wires from the boiler. I've disconnected, and never made a note of which black wire went where. I thought it did not matter. since both are black.
Boiler is VOKERA "Pinnacle 16".
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Vokera "Pinnacle 16" Schematic
If I have not made a mistake, this is how my VOKERA "Pinnacle 16" was wired up.
In the Installation and Service Instructions, an example of the "S Plan System" is given. It is not like this schematic.
In the Service Instructions, the two switches inside the motorised actuators (Danfoss HPA2) are wired in parallel, but both wires (orange - grey) just go into the boiler (to M7, pins 2 & 3).
The boiler has 5 wires going into it, 3 for mains (L N E) and two wires
- both coloured black.
Here you see that the two switches inside the actuators are both in parallel, but live at one end, and the other (orange wires) goes to a black wire into the bolier.
On this schematic, tracing the other black wire from the boiler, it goes onto pins 2 & 5, of the Danfoss SET 3A timer. Pin 1 (Water ON) goes to the cylinder (water) stat, then through the water actuator motor, then to Neutral. Pin 4(Heater ON) goes through the Room Stat, then through the heater actuator motor, then to Neutral.
There is no link connecting the Live wire, in the timer, to any of the pins numbered 1 to 6. Presumably the Live potential is coming from the boiler -out of the black wire.
Is the schematic I've drawn out correct?
What I don't understand is these black wires. There is no way to tell which black wire should be connected to what. I believe you must connect the right black wire to the switches or the thermostat.
Because of the problem with the black wires coming from the boiler, I don't understand this circuit. I don't know what the black wires go to in the boiler or what they supply. Anybody know?