MCZ/Red Hydro Stoves and boilers - minimum static pressure

Regarding the 'Hydro' stoves (Musa, Ego, Primula, Gardenia, etc.), do you know if they have a minimum threshold working pressure? All the literature I have seen for these ranges refer to them only operating on sealed systems & 1 Bar minimum. My question is whether they can be run on an open vented system and what the minimum head is required for them to operate. For example we know that the Compact 24 can run sealed or open, and needs a minimum 0.3 Bar when open; and the Practika has no pump/pressure switch so can run with minimal head, but the picture for these Hydro's is for me a little unclear.?

The main goal is to avoid cavitation and to avoid it (vapour forming within the circulator) it is necessary to maintain at the circulator suction port an
adequately high positive pressure (static head) in relation to the vapour pressure of the fluid being handled.

For higher altitudes: add 0.1m head/100m height increase.
These minimum heads must be respectively increased when handling fluids of higher temperatures or lower densities,
higher resistances at the circulator suction side and in regions of lower atmospheric pressures.


Of course this answer  is not made using my poor english but with the help of the user manual of the circulator .

In a few words the open vent solution is always possible when you can garantee at least 0,3 bar .
In case the stove is installed in a mountain place ( 1000mt) you should have 0,4 bar

NOTE: The water pressure sensor on the pump group is set to 0.4 Bar according to MCZ - therefore there is a risk that the alarm will be raised when the minimum stated head is applied to a system.

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