If it is the unit that you say it is then it seems to be a Megaflow system used as an immersion heater without gas or oil boiler to heat the water and central heating.
Is the pressure ok, do you have a pressure release valve fitted to the unit and I think on the box with the electrical connection to the unit there is a reset switch.
If it is the unit that you say it is then it seems to be a Megaflow system used as an immersion heater without gas or oil boiler to heat the water and central heating.
Is the pressure ok, do you have a pressure release valve fitted to the unit and I think on the box with the electrical connection to the unit there is a reset switch.