Ariston ecoGENUS 24 MFFI User guide

Servicing
Instructions
Type C Boilers
G.C.N: 41-116-03
47-116-17
LEAVE THESE INSTRUCTIONS
WITH THE END-USER
Condensing
Country of destination: GB

2
1. SERVICING INSTRUCTIONS
1.1 REPLACEMENT OF PARTS
1.2 TOGAIN GENERAL ACCESS
- Lowering the control panel and removing the front panel
- Removing the side panels
1.3 ACCESS TO THE COMBUSTION CHAMBER
- Removing the sealed chamber front cover
- Removing the fan
- Removing the burner
- Removing the electrodes
- Removing the heat exchanger inspection panel
- Removing the condensate collector
- Removing the condensate trap
- Removing the injector
1.4 ACCESS TO THE GAS VALVE
- Removing the gas valve
1.5 ACCESS TO THE WATER CIRCUIT
- Removing the D.H.W. (secondary) exchanger
- Removing the safety valve
- Removing the automatic air vent
- Removing the main circuit flow switch
- Removing the diverter valve actuator
- Removing the D.H.W. flow switch
- Removing the pump
- Removing the pressure gauge
- Removing the expansion vessel
- Removing the D.H.W. temperature sensor (N.T.C.)
- Removing the C.H. flow temperature sensor (N.T.C.)
- Removing the C.H. return temperature sensor (N.T.C.)
1.6 ACCESS TO THE CONTROL SYSTEM
- Checking the fuses
- Removing the time clock
- Removing the P.C.B.s
2. FAULT FINDING
2.1 FAULT FINDING GUIDE (FLOW-CHART)
3. ELECTRICAL DIAGRAMS
4. SHORT SPARE PARTS LIST
TABLE OF CONTENTS

3
FIG. 1.2
FIG. 1.1
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 TOGAIN 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 lower the control panel and dismantle the front part of the casing,
proceed as follows:
1. Unscrew screws “A” (1/4 turn only) (FIG. 1.1 + FIG. 1.2) and rotate the
control panel forward;
2. Unscrew the screws “B” (FIG. 1.3) and unhook the front panel by lifting it.
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 electrical system checks must be carried out to
ensure electrical safety (i.e. polarity, earth continuity, resistance to earth and
short circuit).
B
A
A
A
B
FIG. 1.3

4
Removing the side panels
1. Remove the screws “C” (FIG. 1.4);
2. Pull each panel away from the boiler, then lift the panel
up and away from the boiler.
1.3 ACCESS TO THE
COMBUSTION CHAMBER
D
FIG. 1.5
D
FIG. 1.4
C
CC
C
D D
Removing the sealed chamber front cover
1. Remove the screws “D” (FIG. 1.5);
2. Pull the cover away from the boiler (FIG. 1.6).
FIG. 1.6

5
Removing the fan
1. Loosen nut “E” (FIG. 1.7);
2. Pull off the hose “F” and disconnect the electrical
connector “G” (FIG. 1.8);
3. Remove the nuts “H” (FIG. 1.9);
4. Pull the fan away from the exchanger (FIG. 1.10).
FIG. 1.10
E
FIG. 1.9
FIG. 1.7
FIG. 1.8
F
G
H
H
H

6
Removing the burner
With the fan removed (see previous section);
1. Slide the burner from its housing (FIG. 1.11).
FIG. 1.13
J
I
J
Removing the electrodes
1. Pull off the ignition cable “I” (FIG. 1.12);
2. Remove the two allen bolts “J” (FIG. 1.13);
3. Extract the electodes (FIG. 1.14).
FIG. 1.12
FIG. 1.11
FIG. 1.14
Removing the combustion chamber inspection panel
1. Remove the four nuts “K” (FIG. 1.15);
2. Remove the inspection panel (FIG. 1.16).
FIG. 1.15
KK
FIG. 1.16
K
K

7
Removing the condensate collector
1. Remove the nuts “L” from each side of front of the
collector (FIG. 1.17);
2. Remove the nuts “M” from each side of rear of the
collector (FIG. 1.18);
3. Release the condesate trap union “N” (FIG. 1.19);
4. Separate the collector from the combustion
chamber(FIG. 1.20);
5. Remove the condensate collector (FIG. 1.21).
FIG. 1.17
L
FIG. 1.18
M
FIG. 1.19
FIG. 1.20
FIG. 1.21
N

8
Removing the condensate trap
1. Loosen the union “O” (FIG. 1.22);
2. Remove the condensate trap (FIG. 1.23).
FIG. 1.22
O
Removing the injector
See the section on removing the fan before carring out this
procedure
1. Disconnect all connections from the fan and remove
(FIG. 124);
2. Remove the four screws “P” (FIG. 125);
3. Unscrew the injector “Q” using a suitable screwdriver
(FIG. 126);
4. Remove the injector (FIG. 127).
Fig. 1.23
Fig. 1.24
Fig. 1.25
P

9
FIG. 1.26
FIG. 1.27
Q

10
1.4 ACCESS TO THE GAS VALVE
FIG. 1.28
S
R
Removing the gas valve
1. Disconnect the electrical connection “R” from the gas
valve (FIG. 128);
2. Release the top nut “S” (FIG. 1.29);
3. Remove the screws “T” from the bottom of the gas valve
pipe (FIG. 1.30);
4. Remove the gas valve (FIG. 1.31).
FIG. 1.29
FIG. 1.30
FIG. 1.31
T T

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Removing the safety valve
1. Loosen union “W” (Fig. 1.35);
2. Unscrew and remove the valve (Fig. 1.36).
1.5 ACCESS TO THE WATER CIRCUIT
FIG. 1.36
Removing the D.H.W. (secondary)
exchanger
1. Remove the screw “U” (FIG. 1.32);
2. Remove the screw “V” (FIG. 1.33);
3. Push the exchanger towards the rear of the boiler, lift
upwards and remove from the front of the boiler (FIG.
1.34);
4. Before replacing the exchanger ensure that the O-rings
are in good condition and replace if necessary.
Important! Before any component is removed, the boiler
must be drained of all water.
FIG. 1.34
FIG. 1.35
U
FIG. 1.32
FIG. 1.33
V
W

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Removing the automatic air vent
1. Unscrew valve “X” (FIG. 1.37);
2. Remove (FIG. 1.38).
Removing the main circuit flow switch
1. Release the retaining clip “Y” (FIG. 1.40);
2. Remove the main circuit flow switch.
FIG. 1.37
FIG. 1.38
FIG. 1.40
X
Y
B1
Z
A1
FIG. 1.41
Removing the diverter valve actuator
1. Unplug the electrical connector “Z” (FIG. 1.41);
2. Release the retaining clip “A1” and remove the diverter
valve actuator (FIG. 1.42).
Removing the D.H.W. flow switch
1. Release the retaining clip “B1” (FIG. 1.43);
2. Remove the D.H.W. flow switch.
FIG. 1.42
FIG. 1.43

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Removing the pump
1. Unplug the electrical connection “C1” (FIG. 1.44);
2. Release the nut “D1” (FIG. 1.45);
3. Release the nut “E1” (FIG. 1.46);
4. Remove the pump (FIG. 1.47).
E1
D1
C1
FIG. 1.44
FIG. 1.47
FIG. 1.46
FIG. 1.45

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Removing the expansion vessel
See the section on removing the condesate trap before
carrying out this procedure
1. Loosen nut “H1” (FIG. 1.51);
2. Loosen nut “I1” and remove backnut “J1” (FIG. 1.52);
3. Remove the expansion vessel (FIG. 1.53).
Removing the pressure gauge
1. Release coupling “F1” (FIG. 1.48);
2. Ease the pressure gauge “G1” through the control panel
from the rear (FIG. 1.49);
3. Remove the pressure gauge. (FIG 1.50).
F1
G1
FIG. 1.48
FIG. 1.49
FIG. 1.50
H1
I1
FIG. 1.51
FIG. 1.52
FIG. 1.53
J1

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Removing the D.H.W. temperature probe (N.T.C.) (MFFI
only)
1. Remove the electrical connector “K1” by pulling off
(Fig. 1.54);
2. Unscrew and remove the D.H.W. temperature probe “L1”
(FIG. 1.55).
K1
L1
FIG. 1.54
FIG. 1.55
M1
FIG. 1.56
Removing the C.H. flow temperature probe (N.T.C.)
1. Remove the electrical connector “M1” by pulling off
(Fig. 1.56);
2. Unscrew and remove the C.H.flow temperature probe
“N1” (FIG. 1.57).
O1
P1
FIG. 1.58
FIG. 1.59
Removing the C.H. return temperature probe (N.T.C.)
1. Remove the electrical connector “O1” by pulling off
(Fig. 1.58);
2. Unscrew and remove the C.H. return temperature probe
“P1” (FIG. 1.59).
N1
FIG. 1.57

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Checking the fuses
1. Remove the inspection cover on the reverse of the
control panel (FIG. 1.60);
2. Remove the fuses by pushing and rotating fuse holders
“Q1” (FIG. 1.61).
1.6 ACCESS TO THE CONTROL SYSTEM Removing the time clock
1. Remove the inspection cover on the reverse of the
control panel (FIG. 1.60);
2. Lower the time clock door (FIG. 1.62);
3. Unplug the electrical connection “R1”from the time clock
(FIG. 1.63);
4. Gently squeeze each end of the time clock and push
through the control panel (FIG. 1.64).
Q1
FIG. 1.60
FIG. 1.61
FIG. 1.64
FIG. 1.62
FIG. 1.63
R1

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Removing the P.C.B.s
1. Remove the inspection cover on the reverse of the
control panel (FIG. 1.60);
2. Remove the screws “S1” (FIG. 1.65 & FIG. 1.66);
3. Remove the facia panel (FIG. 1.67);
5. Disconnect the connection cable ”T1” (FIG. 1.68);
6. Unplug the electrical connectors “U1” from the main
P.C.B. (Fig. 1.69);
7. Remove the main P.C.B. mounting screws “V1’ (four in
total) (FIG. 1.70);
8. Remove the main P.C.B. (FIG. 1.71);
9. Remove the display P.C.B. mounting screws “W1’ (FIG.
1.72);
10.Remove the display P.C.B. (FIG. 1.73);
11.Replace either P.C.B. in reverse order.
FIG. 1.67
S1
FIG. 1.65
FIG. 1.66
S1
FIG. 1.70
T1
FIG. 1.68
FIG. 1.69
U1
S1
S1
U1
U1
V1
V1
FIG. 1.71

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W1
FIG. 1.72
FIG. 1.73
W1
W1
W1

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2. FAULT FINDING
TABLE
I and II YES
YES
YES
NO NO
IS THE
POWER L.E.D. AND
DISPLAY ON?
DOES A STOP CODE
APPEAR ON THE DISPLAY?
POSITION OF THE SUMMER/
WINTER SELECTOR
1. Check the fuses
2. Check the power supply to
the control panel
3. Check/replace the
ON/OFF button
4. Check the connection between
the main and display P.C.B.s
5. Check/replace the
main and display P.C.B.s
NO
PUSH THE ON/OFF
BUTTON TO ON
MAKE SURE THAT:
1. There is sufficient water in the system
2. The gas is turned on
3. The electrical supply is turned on
SUMMER WINTER
COMFORT
SELECTOR ON/OFF:
green L.E.D. on
YES: COMFORT ON YES: COMFORT ON
Flow
temperature
<40°C
COMFORT
SELECTOR ON/OFF:
green L.E.D. on
Flow
temperature
>50°C
Flow
temperature
<40°C
Flow
temperature
>50°C
NO:
COMFORT OFF
NO:
COMFORT OFF YES
NO
YES
NO
NO
YES
NO
YES
YES YES
D.H.W.
IS BEING
DRAWN?
D.H.W.
IS BEING
DRAWN?
YES
NO
MUST
THE TIME CLOCK
AND/OR ROOM THERMOSTAT
BE ACTIVATED?
NO
NO
BUILT-IN
ELECTRONIC
ANTI-FROST DEVICE:
Is there a condition for it to be active?
(- flow temp. < 3°C
- outdoor temp. < -3°C (outdoor sensor optional)
- Jumper 4 selects the pump
for continuous
operation)
BUILT-IN
ELECTRONIC
ANTI-FROST DEVICE:
Is there a condition for it to be active?
(- flow temp. < 3°C
- outdoor temp. < -3°C (outdoor sensor optional)
- Jumper 4 selects the pump
for continuous
operation)
THERE IS NO CALL FOR PUMP OPERATION THERE IS NO CALL FOR PUMP OPERATION
A
It is possible to detect and correct any defect by using the standard fault
finding diagrams described in this chapter.
2.1 FAULT FINDING GUIDE
(FLOW-CHARTS)
Model 24 MFFI

20
YES
NO
MAKE SURE THAT:
1. There is sufficient water in the system
2. The gas is turned on
3. The electrical supply is turned on
PUSH THE ON/OFF
BUTTON TO ON
IS THE
POWER L.E.D. AND
DISPLAY ON?
DOES A STOP CODE
APPEAR ON THE DISPLAY?
POSITION OF THE SUMMER/
WINTER SELECTOR
SUMMER WINTER
NO
YES
ON/OFF button
5. Check/replace the
1. Check the fuses
2. Check the power supply to
3. Check/replace the
4. Check the connection between
main and display P.C.B.s
the control panel
the main and display P.C.B.s
I and II
TABLE
SELECTOR
C.H. ONLY
ON/OFF ON/OFF
C.H. ONLY
SELECTOR
The
C.H. flow
temperature
is lower than 80°C
and the temperature of the
cylinder is at least 5°C
below the one
selected.
The
C.H. flow
temperature
is lower than 80°C
and the temperature of the
cylinder is at least 5°C
below the one
selected.
ON (green L.E.D. on):
cylinder excluded ON (green L.E.D. on):
cylinder excluded
NO NO
YES YES
YES
NO
OFF (green L.E.D. off):
cylinder active OFF (green L.E.D. off):
cylinder active
MUST
THE TIME CLOCK
AND/OR ROOM THERMOSTAT
BE ACTIVATED?
ANTI-FROST DEVICE:
Is there a condition for it to be active?
(- flow temp. < 3°C
- outdoor temp. < -3°C (outdoor sensor optional)
- Jumper 4 selects the pump
for continuous
operation)
BUILT-IN
ELECTRONIC
THERE IS NO CALL FOR PUMP OPERATION
YES
NO
BUILT-IN
ELECTRONIC
ANTI-FROST DEVICE:
Is there a condition for it to be active?
(- flow temp. < 3°C
- outdoor temp. < -3°C (outdoor sensor optional)
- Jumper 4 selects the pump
for continuous
operation)
THERE IS NO CALL FOR PUMP OPERATION
A
Model 24 RFFI System