Ariston 28 MFFI User Manual

End User  
Manual  
microGENUS II 24 MFFI  
microGENUS II 28 MFFI  
microGENUS II 31 MFFI  
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Country of destination: GB/IE  
CONTROL PANEL  
I
J
K
E
C
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LEGEND:  
A - On/Off Switch  
B - Domestic Hot Water Temperature Adjustment  
C - Central Heating Temperature Adjustment  
D - Reset Button  
E - Comfort Mode Selector  
F - Hot Water (Summer Mode LED - Green)  
G - Ignition/Overheat Lockout LED (Red)  
H - Central Heating (Winter Mode) LED (Green)  
I - Digital Display (Fault Code/Water Temperature)  
J - Time Clock  
K-Central Heating System Pressure Gauge  
2. OPERATING INSTRUCTIONS  
CAUTION  
In the United Kingdom installation, start-up, adjustments and maintenance must be  
performed by a CORGI Registered Installer in accordance with the installation  
standards currently in effect, as well as with any and all local health and safety  
standards i.e.. CORGI.  
K
In the Republic of Ireland the installation and initial start up of the appliance must  
be carried out by a Competent Person in accordance with the current edition of  
I.S.813 “Domestic Gas Installations”, the current Building Regulations, reference  
should also be made to the current ETCI rules for electrical installation.  
HELPFUL SUGGESTIONS  
To get the most out of your boiler, we have provided you with some useful advice on  
proper use and maintenance:  
- Periodically check the system pressure using the pressure gauge “D”, make sure that  
the pressure is at 1.5 bar when the system is off and cool. If the pressure is below the  
minimum recommended value (1 bar). To refill the system, open the two black handles  
connected to the silver flexible hose, once the pressure gauge “K” reads 1.5 bar close  
the valves again.  
NOTE: DO NOT UNDER ANY CIRCUMSTANCES USE THE APPLIANCE WITH THE PRESSURE GAUGE  
READING ZERO.  
- The outer panels of the unit's case must only be cleaned with a damp cloth. Do not use  
abrasive cleaners. The control panel can be wiped with either a damp or dry cloth.  
Spray polishes must not be used on the control panel surface or knobs. Care must be  
taken to prevent any liquid from entering the appliance.  
PRACTICAL TIPS  
- If the water is very hard, it is recommended that a water softener be added to the  
system so as to reduce the formation of limescale in the boiler exchangers. This will  
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ensure that the efficiency of the unit remains the same over time, reducing gas  
consumption and maintenance costs.  
M
N
- If the boiler should be out of use for a prolonged period, it is recommended that the  
electrical power supply be disconnected and that the external gas cock “M” and “N”  
be closed. If low temperatures are expected, the boiler and system pipe work should be  
drained in order to prevent frost damage.  
- To improve comfort and take full advantage of the heat produced by the boiler, it is  
recommended that an external (room) thermostat be installed.  
- It is good practice to clean and service the appliance and central heating system every  
year. Call an Authorised Service Centre.  
IGNITION PROCEDURE  
Turn the selector knob “A” to the “I” position. After a short delay the display will indicate  
onindicating that the boiler is ready to operate. The electronic control unit will ignite the  
burner, without any manual intervention but in response to the request for Domestic Hot  
Water or Central heating. If, after approximately 10 seconds, the burner has not ignited,  
the boiler safety devices will shut off the gas and the display will  
A0 1  
indicate the fault code A . To reset the ignition system, the reset  
A
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button “D” must be pressed and released. Should the boiler fail to  
ignite a second time, check that the external gas cock is open “N”.  
If the problem persists, contact an Authorised Service Centre.  
PL004D  
PL004D  
WINTER AND SUMMER OPERATING MODES  
In the ‘winter’ operating mode, the boiler will produce both Central  
Heating and Domestic Hot Water. In the ‘summer’ operating mode, the  
boiler will produce only Domestic Hot Water.  
D
PL006C  
Using the knobs on the control panel, the user can select ‘winter’ or ‘summer’ operating  
PL007D  
mode.  
summer  
Keeping the knob “C” at the “  
operating mode, the symbol “  
” position selects the ‘summer’  
“ will illuminate. ‘Winter’ operating  
summer  
mode may be selected by positioning the knob “C” between the  
min. and max. settings. The symbol “ “ will illuminate.  
C
winter  
ADJUSTING THE HEATING  
PL009D  
winter  
It is possible to set the temperature of the Central Heating system  
by adjusting the knob “C”. By positioning the indicator somewhere  
between min. and max., a temperature may be obtained which  
varies from approximately 42˚C to about 82˚C.  
C
PL007C  
The water temperature in the Central Heating circuit may be  
checked on the display.  
PL009D  
EXTERNAL (ROOM) THERMOSTAT CONTROL  
C
If an external (room) thermostat is installed, it is recommended that the temperature of  
the Central Heating system be set by means of the “C” knob, leaving it at max in order  
to obtain the best performance from the boiler and to allow the regulation of the external  
temperature to function efficiently.  
PL008D  
SETTING THE HOT WATER FOR DOMESTIC USE  
C
Both in the winter and summer mode, the temperature of the Domestic Hot Water may be  
adjusted by using the “B” knob. A delivery temperature for the water may be chosen in a  
range from 36˚C to about 56˚C, depending on the flow rate of the water and the position  
of the knob between the min. and max. settings.  
PL008D  
The water temperature in the primary circuit may be checked on the display.  
NOTE:  
Should the hot water temperature be insufficientm turn the thermostat  
knob to maximum and reduce the flow rate at the tap. ( A high flow rate will  
reduce the temperature.  
B
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ECONOMY/COMFORT MODE  
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C
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The selector knob “E” allows the user to choose the economy mode (position “E”) or the  
comfort mode (position “C”).  
The economy mode is the normal state for the operation of the boiler, since the domestic  
water is heated up only when a tap is turned on.  
The comfort mode is a special operating state, because the water contained in the  
secondary exchanger and in the primary exchanger is kept in a pre-heated condition,  
thereby allowing a quicker delivery of Domestic Hot Water when required.  
confort  
economy  
PL006D  
C
TURNING OFF THE CENTRAL HEATING  
To turn off the Central Heating, rotate the “C” knob to the “  
” position.  
PL008D  
The boiler will stay in ‘summer’ mode, providing Domestic Hot Water on request.  
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TURNING OFF THE BOILER  
To turn the boiler off, rotate the selector knob “A” to the “0” position (OFF); the display  
will go off. Close the gas cock located under the boiler and turn the electricity supply  
switch (located outside the boiler) to the OFF position.  
PL004D  
3. USEFUL INFORMATION  
AND TROUBLESHOOTING  
BOILER SHUTDOWN SITUATIONS  
The boiler is equipped with safety devices that intervene in certain situations and shut it  
off. Most of these situations are signalled by means of the L.E.D.s and in some  
circumstances the user may be able to remedy them.  
SHUTDOWN DUE TO IGNITION FAILURE  
This anomaly is indicated by A 0 1on the display. To reset the boiler, press and then  
release button “D”.  
At this point, the electronic ignition system will attempt to light the burner again.  
Should the boiler fail to ignite a second time, check that the external gas cock is  
open. If the problem persists, contact an Authorised Service Centre.  
SHUTDOWN DUE TO OVERHEATING  
PL007D  
This anomaly is indicated by A 0 3 on the display. The boiler has shutdown because  
the safety thermostat detected that the boiler temperature has exceeded the maximum  
limit.  
To reset, wait until the boiler has cooled and press button “D”.  
If the safety thermostat operates on a frequent basis, contact one of our Authorised  
Service Centres.  
PL055D  
SHUTDOWN DUE TO INSUFFICIENT WATER CIRCULATION  
This anomaly is indicated by E 0 2 on the display.  
One of the possible causes of this shutdown situation could be the lack of water in the  
boiler or water circulation failure in the primary heating circuit.  
Check the system pressure on the pressure gauge “K” and, if it  
is less than 0.5 bar, try bringing the system pressure up to a  
mean value of 1.0 bar by opening the water inlet valve as  
instructed on page 3. Then reset by pressing button “D”.  
K
OTHER SHUTDOWN SITUATIONS  
PL012D  
Should a shutdown situation indicated on the display by the following letters and figures  
occur, E04, E05, E06, E07, E08, E09, E20, E33, E34 contact one of our Authorised  
Service Centres.  
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