Biasi RIVA COMPACT HE MK2 M96A.24SR/C User manual

Wall hung, fan flue, room sealed, high efficiency gas boiler
Service manual
RIVA COMPACT HE MK2
Models: G.C. Appl. No.
M96A.24SR/C 41---583---09 System boiler
M96A.28SR/C 41---583---10 System boiler
Leave this manual adjacent to the gas meter

Ta b l e o f c o n t e n t s
1 Overall information 1..................
1.1 Overall View 1.........................
1.2 Hydraulic diagram 1....................
2 General access and emptying
hydraulic circuits 2....................
2.1 Nomenclature 2........................
2.2 Body panels 2.........................
2.3 Control panel 2........................
2.4 Access to the sealed chamber 3.........
2.5 Emptying the primary circuit 3...........
3Diagrams 4...........................
3.1 Wiring diagram 4.......................
3.2 Circuit voltages 5......................
4Faultfinding 6........................
5 Primary heat exchanger 8..............
5.1 Function 8.............................
5.2 Removal 8............................
5.3 Cleaning 8............................
6 Condensing heat exchanger 10..........
6.1 Function 10.............................
6.2 Removal 10............................
6.3 Cleaning 10............................
7Pump 12...............................
7.1 Function 12.............................
7.2 Checks 12.............................
7.3 Removal 12............................
8 Electronic control/ignition p.c.b. 14......
8.1 Function 14.............................
8.2 Selection and adjustment devices 14......
8.3 Checking the temperature 15.............
8.4 Operation lights 15......................
8.5 Setting the boiler control function modes 16
8.6 Useful output setting 16..................
8.7 C.H. only mode setting 17................
8.8 Reignition frequency setting 18...........
8.9 Ignition gas pressure adjustment 18.......
8.10 Checks 19.............................
8.11 Removal of the electronic control p.c.b 19..
8.12 Thermal control in the ” ”mode 21......
8.13 Ignition and control sequence 22..........
9 Modulating gas valve 23................
9.1 Function 23.............................
9.2 Nomenclature of the parts (Fig. 2) 23......
9.3 Adjustment 23..........................
9.4 Checks 24.............................
9.5 Removal of the on ---off operators coils 24..
9.6 Removal of the gas valve 24..............
10 Primary circuit flow switch 25...........
10.1 Function 25.............................
10.2 Checks 25.............................
10.3 Removal 25............................
11 Expansion vessel and
temperature -- pressure gauge 26........
11.1 Function 26.............................
11.2 Checks 26.............................
11.3 Removal of the expansion vessel 26.......
11.4 Removal of the temperature---pressure
gauge 26...............................
12 Temperature probe 27..................
12.1 Function 27.............................
12.2 Checks 27.............................
12.3 Removal of the c.h. Temperature probe 27.
13 By--pass valve 28......................
13.1 Function 28.............................
13.2 Removal 28............................
14 Fan and Air pressure sensor 29.........
14.1 Function 29.............................
14.2 Checks 29.............................
14.3 Removal of the Fan 30...................
14.4 Removal of the Air pressure sensor 30.....
15 Ignition and detection electrodes 31.....
15.1 Function 31.............................
15.2 Checks 31.............................
15.3 Removal 31............................
16 Safety thermostat 32...................
16.1 Function 32.............................
16.2 Checks 32.............................
16.3 Removal 32............................
17 Flue temperature probe NTC 33.........
17.1 Function 33.............................
17.2 Checks 33.............................
17.3 Removal 33............................
18 Condensate trap 35....................
18.1 Function 35.............................
18.2 Removal 35............................
19 Short spare parts list 36................

1
1Overall information
1.1 Overall View
Fan
Safety
thermostat
Main heat
exchanger
Burner
Ignition
electrodes
Gas valve
Control
panel
Combustion
chamber
Automatic
air release
Pump
Expansion
vessel
Detection
electrode
valve
Condensing
C.h. temp.
Flue temperature
probe NTC
Primary circuit
heat exchanger
Condensate
trap
pressure switch
Air pressure sensor
probe
B y --- p a s s
valve
C.h. pressure
relief valve
1.2 Hydraulic diagram
Central heating (c.h.) operation
C.h.
water flow
C.h.
water return

2
2General access and emptying
hydraulic circuits
2.1 Nomenclature
2
6
1
54
3
Fig. 1
1 Right side panel
2 Front panel
3 Control panel lid
4 Control panel cover
5Servicepanel
6 Left side panel
2.2 Body panels
Warning: isolate the boiler from the mains
electricity supply before removing any
covering or component.
For the most part of the check and maintenance oper-
ations it is necessary to remove one or more panels of
the case.
Thesidepanelscanberemovedonlyaftertheremoval
of the front panel.
To remove the front panel remove screws A(Fig. 2), lift
the panel and remove it.
A
Fig. 2
To remove the side panels loosen the screws Band C
(Fig. 3), bring the base of the panels away from the
boiler and lift them, freeing them from the top hooks.
B
D
CB
Fig. 3 --- bottom view of the boiler
2.3 Control panel
Warning: isolate the boiler from the mains
electricity supply before removing any
covering or component.
To gain access to the parts located inside the control
panel proceed as follows:
1 Remove the front panel of the case
2 Loosen the screws Band C(Fig. 3).
3RemovethescrewsD
4 Move the lower part of the side panels as indi-
cated in Fig. 4 and pull the control panel.
When completely pulled out, the panel can rotate
45˚downwards to facilitate the service oper-
ations on the internal parts.

General access and emptying hydraulic circuits
3
Fig. 4
5RemovethescrewsEand remove the service
panel (Fig. 5);
6 To gain access to the electronic regulation PCB
remove the screws Fand remove the control pan-
el lid (Fig. 5);
E
F
F
Fig. 5
2.4 Access to the sealed chamber
G
G
Fig. 6
To gain access to the parts contained in the sealed
chamber it is necessary to remove the lid of the sealed
chamber.
For this purpose, remove the front and side panels of
the case, remove the screws Gas indicated in Fig. 6
and remove the lid.
2.5 Emptying the primary circuit
1 Close the c.h. circuit flow and return cocks H.
(Fig. 7).
H
Fig. 7 --- bottom view of the boiler
2 Remove the front and right panels of the boiler.
3 Open the drain tap I(Fig. 8) until the boiler is com-
pletely emptied.
4 Close drain tap again once the emptying has
been completed.
I
Fig. 8

4
3Diagrams
3.1 Wiring diagram
1
23
L N
gnye bubn
bnbkbu
bn bubn bk bu
bu
bn gnye
bn bu
bn bu
bn
bu
M
~
bu bn gnye
bk
bk
t
wh
wh
tbu
bu
bk
bk
Ignition
electrodes Flame detection
electrode
External controls
terminal block
Electric supply
terminal block
Pump Fan
M
~
Primary circuit
flow switch
Air pressure
sensor
C.h. temperature
probe NTC
Modulating
gas valve
Safety
thermostat
Flue
probe NTC
ye
gy
bn = brown
bu = blue
bk = black
wh = white
rd = red
gy = grey
gn = green
ye = yellow
vt = violet
og = orange
gnye = green/yellow
bubn gnye
bu
bk
bu bu
bn
bu
bk wh wh
rd
rd
P
rd
ye
gy
rd
gy
ye
gy
gy
bk
bk
ye
gy
1
2
3
gnye
1
3
4
bu
* = alternative

Diagrams
5
3.2 Circuit voltages
during c.h. operation
Electrical voltages with burner on
Supply network
230~
230~
Pump
230~
Modulating
Gas valve
Safety
thermostat
0
Fan
230~
+12 V DC
Air
sensor
pressure
0,5 ± 4,5 V DC

6
4Fault finding
Components to check
Section of the manual ! (note ref. in brackets)
---
(1)
---
(2)
---
(3)
18.1 ---
(4)
7.2 8.10 9.4 10.2 12.2 13 14.2 15.2 16.2 17.1 ---
(7)
---
(8)
--- ---
L o c k --- o u t s i g n a l l a m p r e d
Defect #
Power supply line
Gas supply line
Flue pipes
Condensate drain pipe and trap
C.h. circuit
Pump
Fuses (Electronic p.c.b.)
Electronic p.c.b.
Boiler settings
Gas valve (on---off operators)
Gas valve (modulating operator)
Main circuit flow switch
Main circuit temp. probe
B y --- p a s s v a l v e
Fan
Air pressure sensor
Ignition electrode
Detection electrode
Safety thermostat
Flue probe NTC
Injectors
Expansion vessel
Safety valve
Pressure gauge
By pressing the reset push---button the boiler turns on and operates cor- rectly.
J J
(6)
J J J
By pressing the reset push---button the boiler starts the ignition cycle. The burner doesn’t light on, the igni-
tion sparks continue and the boiler locks again.
J J J J J
ON
By pressing the reset push---button the boiler starts the ignition cycle. The burner lights on, the ignition sparks continue and the boiler locks again.
J J J J J J
The boiler does not start either in c/h mode. All the operation lights OFF Fan still.
J J J
The burner doesn’t light either in c.h. mode. Fan turns.
J J J J J
The burner doesn’t light either in c.h. mode. Fan doesn’t turn.
J J J J J J J
OFF
The boiler lights for a short while on c.h..
J J

7
Components to check
Section of the manual ! (note ref. in brackets)
---------
(8)
---
(7)
17.116.215.214.21312.210.29.48.107.2---
(4)
18.1---
(3)
---
(2)
---
(1)
L o c k --- o u t s i g n a l l a m p r e d
Pressure gauge
Safety valve
Expansion vessel
Injectors
Flue probe NTC
Safety thermostat
Detection electrode
Ignition electrode
Air pressure sensor
Fan
B y --- p a s s v a l v e
Main circuit temp. probe
Main circuit flow switch
Gas valve (modulating operator)
Gas valve (on---off operators)
Boiler settings
Electronic p.c.b.
Fuses (Electronic p.c.b.)
Pump
C.h. circuit
Condensate drain pipe and trap
Flue pipes
Gas supply line
Power supply line
Defect #
On c/h mode the temperature of the main circuit reaches 75°Candthec/h
system does not heat.
J
Incorrect modulation J J J Noisy bolier J J
OFF
The boiler operates correctly but the gas pressure to the burner remains at minimum.
J J
---
Water leaks from the safety valve dur- ing operation on c/h
J J J J
---
Water leaks from the safety valve when the boiler is off.
J J J
Note Useful information can be obtained also from the optical indication given by the appliance oper- ation lights (see section 8.4). 1 Check for 230V~ between line (L) and neutral (N)
Verify the integrity of supply cable, plug and external fuses. Check the polarity of line and neutral connection
2 Verify the tightness of the gas supply pipe, the position of stop
valves. Check the gas pressure at the inlet test point of the gas valve (see sect. 9.3) with the boiler at rest and during operation and compare it with the values given on the installation booklet.
3 Check for soundness and absence of obstructions. Verify that
the flue terminal is correctly installed (see clearances) and en- sure that exhaust gas is not sucked back by the boiler.
4 Check for soundness of the circuit and verify its correct filling
(see also installation manual).
5 A j a m m e d b y --- p a s s c o u l d c a u s e t h e o v e r --- h e a t i n g o f t h e m a i n
circuit and the intervention of the safety thermostat.
6Checktheminimum gas pressure at the outlet test point of the
gas valve (see sect. 9.3) and compare it with the value given on the installation booklet.
7 Verify the cleanness of injectors. 8 Check the pressurization of the expansion vessel. Refer to the
installation manual for proper values.

8
5Primary heat exchanger
5.1 Function
The primary heat exchanger Ain Fig. 1 has the function
of transferring heat produced from combustion of the
gas to the water circulating in it.
A
Fig. 1
The hydraulic circuit is composed of 8 elliptical pipes
connected in parallel (Fig. 2).
Fig. 2
5.2 Removal
Warning: isolate the boiler from the mains
electricity supply before removing any
covering or component.
1 Remove the case panels and the sealed chamber
lid (see section 2).
2 Empty the primary circuit of the boiler.
3 Remove the combustion chamber lid Bby un-
screwing the screws C(Fig. 3).
4RemovethescrewsDand the plate E.
5RemovetheclipF
6 Loosen the connection Gand slightly move the
pipe Hupwards.
7RemovetheclipIand the safety thermostat J.It
is not necessary to disconnect it from the wiring.
D
M
C
B
E
C
G
I
J
K
L
H
O
F
N
Fig. 3
8 Loosen the connection Kand move the pipe L
downwards freeing it from the connection of the
primary het exchanger.
9RemovetheclipM
10 Loosen the connection N
11 free the pipe Ofrom the connection of the con-
densing heat exchanger; lift and and rotate it to-
wards right.
12 Remove the heat exchanger by sliding it for-
wards.
13 Reassemble the boiler carrying out the removal
operations in reverse order. Fit the clip Iwith the
arrow pointing upwards as illustrated in Fig. 3.
IMPORTANT -- do not force the connection Gwhen
tighting it.
5.3 Cleaning
If there are deposits of soot or dirt between the blades
of the heat exchanger, clean with a brush or non---me-
tallic bristle brush.
In any case, avoid any actions that can damage the pro-
tective varnish with which the exchanger has been cov-
ered.