Hi, I have a Daikin Altherma 3 monobloc with the Daikin DHW cylinder, I need to move some radiators around which will of course involve draining the CH system. Is there any way to configure the MMI to just use immersion for DHW heating for a few weeks (so I don’t have to refill the CH circuit)?
Thx in advance.
For a short time you could wire the immersion to a 3 pin plug. Just be careful how long you run the heater as you are running at the plugs limit
Never use a 13 amp socket in an airing cupboard as it is not rated for the temperature.
I would temporary connect the immersion to the circuit that power the MMI, should only need one cable to be changed.
Looks like in installer mode under booster heater you can set this to on if compressor is off
“ 
3 Compressor off: The booster heater is
allowed when the heat pump is NOT active in
domestic hot water operation.”
I