MCZ Hydro Stoves - A16 alarm

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Note: The following processes can only be carried out by a suitably qualified Biomass Engineer


There have been instances reported of an A16 alarm being raised on the MCZ Hydro stoves (Musa, Ego, Suite, Club,Star) with the description "Water Overpressure Alarm" or "Manostat". These appliances have no water pressure switch so the reporting of such an alarm is an anomoly due to incorrect configuration during installation/commissioning, or maintenance of the appliance. This can occur when accessing or altering some Technical parameters on the older versions of the stove.

It can be cleared by undertaking the following steps:



  • Press and hold the Escape button (upper left of display panel) until alarm clears - approx 5 seconds.
  • Enter the Technical Menu. Select "Mano Stat" and change it to Off.
  • The A16 alarm will now be activated again. Press and hold the On/Off button on the control panel until the alarm clears and the display reads 'Check' - approx 5 seconds.


If the above sequence does not clear the alarm, repeat it at least once to check that it has was followed correctly. If however the alarm still fails to clear, the next option is to perform a reset of the motherboard.

Before proceeding with this operation, note that this process will reset the motherboard to factory default settings. Ensure that you have recorded all the appliance settings, configurations etc. to allow them to be reapplied afterwards.

Firstly, access the motherboard of the appliance by removing the right hand side panel. Then locate the reset button on the motherboard: This is along the edge of the board and is a small black button on a square base - see below image for reference:


Active Motherboard reset button


Now perform the following steps:


  • Turn the appliance off at the main power switch on the rear of the appliance.
  • Turn the appliance back on again
  • As soon as this is done, press and hold the rest button on the board until a 'beep' is heard.
  • As soon as the beep is heard, release the button. A second beep will the shortly be heard. The board is now reset.
  • If the second beep is not heard, repeat the whole process from the first step.


Once the board is successfully reset, go to the control panel: The panel will now be displaying 'Stove Type'. Enter the relevent stove type number for the appliance concerned:

04 - Ego, Star 05 - Suite, Club, Musa (15KW) 08 - Suite, Club, Musa (22KW)


The appliance's menu language will now be in Italian: Go to 'Impostazioni' (Settings), then Lingua (Language) and set back to English. The alarm should now have cleared. If at this stage it still remains, repeat the initial steps at the top of the article.


If the alarm still remains at this stage, and it is not possible to enter the Technical Menu in any way to deactivate the Manostat function, it will be necessary to repeat the motherboard reset process, but instead of setting the stove back to its correct product type, the stove needs to be temporarily set to an Air stove product: Use Product type 02 for this. Once set and the language updated, the alarm will have cleared, or will be able to be so by repeating the initial steps. Now, immediately repeat the motherboard reset function one more time, but now set the stove to the correct Hydro product type.