Ariston A/27 MFFI GAS Adjustments, Draining the System, Limescale Build-up, Safety Shut-off

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off status. After the system has been allowed to cool, the system can be reset

 

 

by pressing the button “A”.

 

 

4 - Limescale Build-up

 

 

This is an indirect control (actuated through the regulation of the temperature in

 

 

the primary heat exchanger) on the formation of limescale in the secondary

 

 

heat exchanger. Regardless of the flow rate and the temperature in the circuit

 

 

for the domestic hot water, the temperature is limited to 62°C.

 

 

5 - Safety Shut-off

 

 

At the start of every lighting phase, the P.C.B. performs a series of internal

 

 

controls. If a malfunction occurs, the boiler will shutdown until the problem has

 

 

been resolved.

3.9

Draining the System

Draining the heating system.

 

 

The heating system must be emptied as follows:

 

 

- Turn off the boiler;

 

 

- Open the drain valve for the system and place a container below to catch the

 

 

water that comes out;

 

 

- Empty the system at the lowest points (where present). If you plan on not

 

 

using the heating system for an extended period of time, it is recommended

 

 

that you add antifreeze with an ethylene glycol base to the water in the

 

 

heating lines and radiators if the ambient temperature drops below 0°C during

 

 

the winter.

 

 

This makes repeated draining of the entire system unnecessary.

Draining the domestic hot water system.

Whenever there is the danger of the temperature dropping below the freezing point, the domestic hot water system must be drained as follows:

- Turn off the general water valve for the household plumbing system; - Turn on all the hot and cold water taps;

- Empty the remaining water from the lowest points in the system (where present).

4.GAS ADJUSTMENTS

CATEGORY II2H3+

 

Methane Gas

Liquid Butane Gas

Liquid Propane Gas

 

 

G20

G30

G31

 

 

 

 

 

Lower Wobbe Index (15°C;1013mbar)

MJ/m 3h

45.67

80.58

70.69

Nominal Delivery Pressure

mbar

20

30

37

Minimum Delivery Pressure

mbar

17

20

25

A/23 MFFI

 

 

 

 

Main Burner: n. 13 jets (ø)

mm

1.,25

0.72

0.72

Consumption (15°C; 1013mbar)

mc/h

2.72

----

----

Consumption (15°C; 1013mbar)

Kg/h

----

2.02

2.02

Gas Cock Outlet Pressure

 

 

 

 

min - max

mbar

11.4- 2.0

27.5 (*) - 5.2

35.0 (*) - 7.0

A/27 MFFI

 

 

 

 

Main Burner: n. 15 jets (ø)

 

1.25

0.72

0.72

Consumption (15°C; 1013mbar)

mc/h

3.16

----

----

Consumption (15°C; 1013mbar)

Kg/h

----

2.35

2.32

Gas Cock Outlet Pressure:

 

 

 

 

max - min

mbar

11.6-2.2

(*) - 4.8

(*) - 6.0

 

 

 

 

 

 

 

 

 

 

(1mbar = 10,197 column of water)

The outlet pressure of the gas cock is obtained by completely loosening the screw on the solenoid. The maximum pressure of the gas to the burner will be equal to the nominal delivery pressure minus the head loss within the gas valve.

B023

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Contents Mffi A/27 Mffi Table of Contents General Instructions General InformationMffi Technical InformationOverall View Mffi A/27 MffiReference Standards Siting the Appliance InstallationClearances Overall DimensionsMounting the Appliance Electrical ConnectionGas Connection Water Connections Safety Valve DischargePipe Work By-passFlue Connections Mains Water Feed Central HeatingFilling Terminal Position B023 Coaxial System Room Thermostat Connection Colours Electrical DiagramB023 Mffi Commissioning Water Circuit DiagramInitial Preparation Filling the Heating SystemRemoving the Front Panel Control PanelSelector Knob for Summer/Winter/Flue Analysis Modes Checks to be run before initial start-up are as follows Initial Start-up Operational AdjustmentsIgnition Failure Circulation FailureOverheating Safety Shut-off GAS AdjustmentsDraining the System Limescale Build-upChanging the Type of Gas MaintenanceMiscellaneous Wiring Diagram for Two Heating ZonesBlue Wiring Diagram for Connection to Ariston Unvented CylinderB023 B023 B023 Manufacturer Merloni TermoSanitari SpA Italy Cod 99 84 1260 112 B023