Ariston Genus Servicing Instructions

Servicing Instructions Type C Boilers G.C.N: 41-116-01

47-116-08 47-116-09 47-116-13

LEA VE THESE INSTRUCTIONS ADJACENT T O THE GAS METER

B005

Page No.

1. SERVICING INSTRUCTIONS

1.1 Replacement of Parts 3

1.2 To Gain General Access

- Removing the Front Panel 3

- Removing the Bottom Cover 4

- Removing the Side Panels 4

1.3 Access to the Combustion Chamber

- Removing the Sealed Combustion Chamber 5

- Removing the Burner and Injectors 5

- Removing the Electrodes 6

- Removing the Main Heat Exchanger 7

- Removing the Air Pressure Switch 7

- Removing the Venturi Device 8

- Removing the Fan 8

1.4 Servicing and Removal of the Gas Valve

- Setting Gas Pressure 10

- Removing the Spark Generator (SIT Sigma Gas Valve) 12

- Removing the Spark Generator (SIT Tandem Gas Valve) 13

- Removing the Gas Valve 14

1.5 Access to the Hydraulic Circuit

- Removing the D.H.W. (Secondary) Exchanger 14

- Removing the Safety Valve 15

- Removing the Automatic Air Vent 15

- Removing the Main Flow Circuit Switch 15

- Removing the Pump 16

- Removing the Pressure Gauge 16

- Removing the Expansion Vessel 17

- Removing the Overheat Thermostat 17

- Removing the Heating Temperature Sensor (N.T.C.) 17

- Removing the D.H.W.Temperature Sensor (N.T.C.) 18

- Removing the Diverter Valve (Genus 27 RFFI Only) 18

1.6 Access to the Control System

- Checking the Fuses 19

- Removing the Time Clock 19

- Removing the P.C.B.s 20

2. FAULT FINDING

2.1 Fault Finding Guide (Flow-chart) 21

2.2 Fault Finding Using the Total Check System 26

3. ELECTRICAL DIAGRAMS

3.1 Electrical Connection 27

3.2 Functional Flow Connection 29

4. SHORT SPARE PARTS LIST

TABLE OF CONTENTS

B005

1. SERVICING INSTRUCTIONS

The life of individual components vary and they will need servicing or replacing as and when faults develop. The fault finding sequence chart in chapter 2 will help to locate which component is the cause of any malfunction, and instructions for removal, inspection and replacement of the individual parts are given in the following pages.

1.1 Replacement of Parts

1.2 To Gain General Access

All testing and maintenance operations on the boiler require the control panel to be lowered.This will also require the removal of the casing.

To dismantle the front part of the casing, proceed as follows:

1. Loosen the two screws “A”located on the bottom par t of the boiler until the first thread on the screws appears

(Fig. 1.1)

;

2. Lift the front panel up until it stops with a click and remove the front panel from the rest of the casing

(Fig. 1.2)

;

4. Unhook the two cords from the locating slots

(Fig. 1.3)

Fig. 1.2

Fig. 1.3

Fig. 1.1

To ensure efficient safe operation, it is recommended that the boiler is serviced annually by a competent person.

Before starting any servicing work, ensure both the gas and electrical supplies to the boiler are isolated and the boiler is cool.

Before and after servicing, a combustion analysis should be made via the flue sampling point (please refer to the Installation Manual for further details).

After servicing, preliminary electr ical system checks must be carried out to ensure electrical safety (i.e. polar ity, earth continuity, resistance to earth and short circuit).

B005

Removing the bottom cover

Remove the screws “B”

Removing the side panels

Remove the screws “C”;

Pull the panel away from the boiler, then lift the panel up and away from the boiler.

Fig. 1.4

Fig. 1.5

Remove the side panels of sealed chamber

(fig. 1.8)

;

Remove the screws “F” of the burner

(see fig. 1.9)

;

Remove the burner

(see fig. 1.10)

;

Remove the injectors using a No. 7 socket spanner;

Replace in reverse order.

Removing the burner and the injectors

B005

Removing the sealed chamber

frontal cover

1.3

Access to the Combustion Chamber

Remove the screws “D”

Remove the screws “E”

Removing the combustion cover

Fig. 1.6

Fig. 1.7

Fig. 1.8

Fig. 1.9

Fig. 1.10

push

B005

Removing the electrodes 1.

Remove rubber gasket “G”

(see fig. 1.11)

;

Disconnect ignition leads by pulling downward

(see fig. 1.12)

;

To remove the flame sensor disconnect the cable at its only connection point close to the P.C.B.

(see fig. 1.13)

;

Remove screw “H” using a Philips No. 2 star tip screwdriver

(see fig. 1.14)

;

Slide the electrode gently downward

(see fig. 1.15).

To replace, repeat the steps in reverse order , paying particular attention to the following:

-Centre the electrode in the positioning hole carefully, otherwise the electrode may break;

-Check that the cables have been connected correctly;

-Check that the rubber gasket covers the cable/electrode connection

point completely.

Fig. 1.11

Fig. 1.12

Fig. 1.13

Fig. 1.14

Fig. 1.15

Disconnect the electrical connections “K” and silicone pipes “L” from their connection points

(see fig. 1.18)

;

Remove screws “J” on the top of the sealed chamber

(see fig. 1.19)

;

Use a No.2 star tip screwdriver to remove the switch from the plate.

Fig. 1.19

Fig. 1.18

B005

Drain the boiler of water;

Release the two connection nuts “I” connecting the exchanger to the flow and return pipes

(see fig. 1.16)

;

Pull it straight out

(see fig. 1.17).

Removing the main heat exchanger

Removing the air pressure switch

Fig. 1.16

Fig. 1.17

B005

Disconnect the silicone pipes “M” and remove the screw “N”

(see fig. 1.20)

;

Extract the venturi

(see fig. 1.21)

Removing the venturi device

Disconnect electrical connections and remove screws “O” using a No.2 star tipped screwdriver

(see fig.1.22)

;

Pull fan to the right and forward and remo ve

(see fig.1.23

);

Remove fan from mounting plate;

Remove screws “P”

(see fig.1.24)

Removing the fan

Fig. 1.20

Fig. 1.21

Fig. 1.22

Fig. 1.23 Fig. 1.24

B005

1.4

Servicing and Removal of the Gas Valve

SIT TANDEM

SIT SIGMA

B005

Setting the minimum and the maximum power of the boiler

1. Check that the supply pressure to the gas valve is a minimum of 20 mbar

for natural gas.

2. To do this, remove the screw “A”. Fit the pipe of the pressure gauge to the pressure connection of the gas valve “B”. When you have completed this operation, replace the screw “A” securely into its housing to seal off the gas.

3. To check the pressure supplied by the gas valve to the burner, remove the screw “C”. Fit the pipe of the pressure gauge to the pressure outlet of the gas valve “D”. Disconnect the compensation pipe either from the gas valve or from the sealed chamber.

4. Set the On/Off button to position < I > and the "summer/winter" switch to the winter position. To set the maximum power, turn on the hot water tap and allow the hot water tap to run at a rate of about 8 litres/minute so that the main burner lights. Adjust nut “E” on the modureg to set the gas pressure (displayed on the pressure gauge) corresponding to the maximum power (see table “A”page 11).

5. T o set the minim um pow er, disconnect a supply terminal from the modureg and adjust screw “F”. Turn the screw clockwise to increase the pressure and counter-clockwise to decrease the pressure (displayed on the pressure gauge) corresponding to the minimum power (see table “A” page

11).

6. When you have completed the above operations, turn off the hot water tap, re-connect the supply terminal to the modureg on the gas valve and replace the cap on the screw of the modureg.

Setting the maximum heating circuit power

7. To set the maximum heating circuit power, place the

On/Off button to position < I > and the "summer/winter" switch to winter position. Tur n the knob of the heating ther mostat clockwise to maximum;

8. Remove the left hand inspection panel of the P.C.B. and fit a small

cross-head screwdriver in to the right hand potentiometer.Tur n clockwise to increase the pressure or counter-clockwise to reduce the pressure. Adjust the setting to the required heating pressure value (displayed on the pressure gauge), as indicated in the diagrams shown in page 11.

9. Turn off the boiler by placing the main switch to the "Off" position.

Setting pressure for soft ignition.

Disconnect the detection electrode connection from the P.C.B. (see fig.

1.13). Start the boiler and during the ignition sequence adjust the centre potentiometer until the gas pressure reads the required gas pressure as per the table below. Once the gas pressure is set turn off the boiler and reconnect the connection to the P.C.B. NB.:It may be necessary to reset the flame failure reset a number of times during this operation.

Setting gas pressures

Recommended pressure for slow ignition

NATURAL GAS (G20) BUTANE GAS (G30) PROPANE GAS (G31)

5 mbar - 1.95 in w.g.

18 mbar - 7.0 in w.g. 19 mbar - 7.4 in w.g.

B005

Regulating the heating power for

natural gas (G20)

Regulating the heating power for

butane gas (G30)

Regulating the heating power for

propane gas (G31)

T ABLE “A”

model 23 model 27

40 38 36 34

model 23 model 27

B005

10. Remove the pipe from the pressure gauge and connect screw “C” to the

pressure outlet in order to seal off the gas.

11.Carefully check the pressure outlets for gas leaks (valve inlet

and outlet).

IMPORTANT!

Whenever you disassemble and reassemble the gas connections, always check for leaks using a soap and water solution.

Setting the anti-cycling device

This appliance is equipped with a potentiometer which delays the ignition of the heating control and is situated on the P.C.B.(see the electrical diagrams). By adjusting the potentiometer, it is possible to change the time interval between the burner shutting down and its next ignition. It is preset at 1 minute and can be adjusted from 0 to 2 minutes. Use this control in particular situations where continuous shutting down and ignition of the main burner occurs.

Anti-cycling

Device

Soft-light

Adjustment

Max Heating

Adjustment

Removing the spark generator (SIT Sigma gas valve)

Disconnect ignition leads “Q” by pulling upwards

(see fig. 1.25)

;

Remove the screws “R”

(see fig. 1.26)

with a Pozidrive

No.2 star tip screwdriver;

Remove the spark generator.

Fig. 1.25

Fig. 1.26 Fig. 1.27

B005

Removing the spark generator (SIT Tandem gas valve)

Disconnect ignition leads “Q1” by pulling upwards

(see fig. 1.28)

;

Remove the screws “R1”

(see fig.1.29)

with a Pozidrive

No.2 star tip screwdriver;

Remove the spark generator.

Fig. 1.28

Fig. 1.29 Fig. 1.30

B005

1.5

Access to Hydraulic Circuits

Fig. 1.35

Removing the gas valve

Disconnect all the cables from the solenoid and modureg;

Remove the spark generator;

Release the top nut “S” using a 30 mm open ended spanner

(see fig. 1.31)

;

Remove the screws “T” from the bottom of the gas valve pipe

(see fig. 1.32)

Attention!!

The gas valve is connected with the two pipes

(as shown) with an O-ring connection.

Important!

Before any component is removed, the boiler

must be drained of all water.

Removing the D.H.W. (secondar y) exchanger

Remove the screw “U”

(see fig. 1.35)

;

Push the exchanger towards the rear of the boiler, lift upwards and remove out of the front of the boiler;

Before replacing the exchanger ensure that the O-rings are in good condition and replace if necessary.

Fig. 1.31

Fig. 1.32

Fig. 1.33

Fig. 1.34

+ 30 hidden pages