Connecting Euroster Uni2 Controller to Buffer & Nefit Thermostat in a Central Heating System

I'm having a woodburner which is heating a buffer tank, this system is operational and I got the buffer to approx 90 degrees. But now I am struggling to connect the buffer to my old fashioned central heating system.
For this I bought a Euroster uni2 controller, a pump with an electric mixing valve and an electric 3-way valve.

The following things are not clear to me;
1) Can I connect my current Nefit thermostat to the Uni2 controller, and connect the Uni2 to my gas boiler?
In this setup the Uni2 will decide based on the temperature in the buffer which heat source is selected.

2) When the buffer temperature is let's say above 50 degrees, the Uni2 will give a signal to the motorized 3-way valve to use the heat from the buffer. Also there goes a signal to the pump unit which will start. The built-in electric mixing valve is also controlled by the Uni2 to prevent a too high temperature in the heating system.

3) When the buffer is in the right temperature range, the Uni2 will shut off the boiler. It will only turn on when there is demand for warm domestic water. There is no hydraulic switcher between the in and outlet from the boiler. (The in and outlet are not connected, and both dead ended (by the 3-way valve) Is this a problem when the system is diverted via the buffer?

Ad1. What exactly is the regulator (Nefit)?
You can connect the UNI2 controller to the gas boiler, but remember that this controller turns on this output whenever there is a heat demand, i.e. when a room regulator connected to the CO1 or CO2 or CWU circuit requires heating. The boiler output is also always shorted when the given circuit is not switched on (in UNI2 settings) with room regulator. This controller is not designed to "choose" which heat source to switch on. Such a choice is when there are two power sensors as it is provided in the UNI3 controller - this, however, does not control the DHW.
Ad2. If the supply sensor (UNI2) is placed in the buffer (and then the buffer will be treated as a heat source) and the temperature at this heat source does not fall below the blanking temperature (set on the controller), then the circuits will be regulated. When the flow temperature (buffer) drops below the blanking temperature, then the circuits are turned off and the controller does not regulate (because it makes no sense to pump cold water).
Ad3. The UNI2 controller turns off the boiler output only when: room regulators connected to it and DHW do not demand heating or when regulators are not connected and the hour schedules are not marked (empty windows at hours). It is worth remembering that UNI2 does not manage the supply temperature by means of the Boiler output. The boiler output is switched on but without flow temperature control. This temperature should be controlled by a separate device (e.g. controller built into the boiler).

We are working on a device that will manage the supply temperature and at the same time control the mixer (just for installation with a buffer) but we do not yet have it on offer.

1) A Nefit ModuLine Easy
2) Clear to me.
3) Too bad that the device is not yet available. What I can do is build a relay in the output between the UNI2 and gas-fired boiler which interrupts the signal from the UNI2 when the CO1 circuit is switched on and there is a heat demand from the room controller.

Only room controllers with a normally open / closed output can be connected to the UNI2 controller. If Nefit has a different type of output (and it seems so in this case) then it cannot be connected to UNI2 and the output from UNI2 cannot be connected to the same place where Nefit was previously connected.

Ah, seems clear. In the drawing I've put in a relay which will break the signal from the easyline room thermostat to the boiler. The signal is special coded Nefit EMS. So I can convert this to an on/off signal which can be connected to the uni 2.
When is your new device on the market? It seems interesting for my situation!



Maybe