Biasi RIVA PLUS M90S.24S User manual

Wall hung, fan flue,roomsealed gasboiler
SERVICEMANUAL
RIVAPLUS
Models: G.C.Appl.No.
M90D.24S47--970--15
M90D.28S47--970--16
M90D.24SR41--970--08
M90D.28SR41--970--09
Leave thismanualadjacent tothegas meter
Biasi U.K.Ltd
Unit31/33,PlanetaryRoad
IndustrialEstate,NeachellsLane
Willenhall,Wolverhampton WV13 3XB
Technicalhelpline:01902 304 400
Web site:www.biasi.co.uk

1
Tableofcontents
1Overall information2..................
1.1Overall View2.........................
1.2Hydraulicdiagram2....................
2Generalaccess andemptying
hydraulic circuits3....................
2.1Nomenclature3........................
2.2Bodypanels3.........................
2.3Controlpanel3........................
2.4Access tothesealedchamber4.........
2.5Emptyingtheprimarycircuit4...........
2.6Emptyingthed.h.w.circuit4............
3Diagrams5...........................
3.1WiringdiagramM90D.24SM90D.28S5...
3.2WiringdiagramM90D.24SR,M90D.28SR7
3.3Functionalflowdiagrams9..............
3.4Circuitvoltages10......................
4Faultfinding12........................
5Primaryheatexchanger14..............
5.1Characteristics14.......................
5.2Removal14............................
5.3Cleaning14............................
6D.h.w.heatexchanger15...............
6.1Function15.............................
6.2Removal15............................
7Pump16...............................
7.1Function16.............................
7.2Checks16.............................
7.3Removal16............................
8Three waydivertervalve17.............
8.1Function17.............................
8.2Checks17.............................
8.3Removalofthe electricactuator17........
8.4Removalofthedivertergroupand
itsinternalparts18......................
9Electronic controlp.c.b.19..............
9.1Function19.............................
9.2Selectionandadjustmentdevices19......
9.3Checkingthetemperature19.............
9.4Operationlights20......................
9.5Dip---switchselectors21.................
9.6Settingjumpers22......................
9.7Ignitiongaspressureadjustment22.......
9.8Maxc.h.poweradjustment22............
9.9Checks22.............................
9.10 Removalofthe electronic controlp.c.b22. .
9.11 Thermalcontrolinthe” ” mode24......
9.12 Thermalcontrolinthe” ” mode24......
10 Full sequenceignitiondevice25.........
10.1Function25.............................
10.2Checks25.............................
10.3Removal25............................
10.4Ignitionandcontrolsequence26..........
11 Modulating gasvalve27................
11.1Function27.............................
11.2Nomenclatureoftheparts27.............
11.3Adjustment27..........................
11.4Checks28.............................
11.5Removaloftheon---off operatorscoils28. .
11.6Removalofthegasvalve28..............
12 Primarycircuitflowswitch29...........
12.1Function29.............................
12.2Checks29.............................
12.3Removal29............................
13 Expansionvesseland
temperature-- pressuregauge30........
13.1Function30.............................
13.2Checks30.............................
13.3Removalofthe expansionvessel30.......
13.4Removalofthetemperature---pressure
gauge30...............................
14 D.h.w.flowswitch,filterandflowlimiter31
14.1Function31.............................
14.2Nomenclatureandlocationofparts31.....
14.3Checks31.............................
14.4Removaloftheflowswitchsensor31......
14.5Removaloftheflowswitchgroup
and d.h.w.circuitfilter31.................
14.6Flowlimiter32..........................
15 Temperatureprobe33..................
15.1Function33.............................
15.2Checks33.............................
15.3Removal33............................
16 By--pass valve34......................
16.1Function34.............................
16.2Removal34............................
17 Fan,venturideviceand
Airpressureswitch35..................
17.1Function35.............................
17.2Checks35.............................
17.3RemovaloftheFan36...................
17.4Inspectionandremovalofthe
venturidevice36........................
17.5RemovaloftheAirpressureswitch37.....
18 Ignitionand detectionelectrodes38.....
18.1Function38.............................
18.2Checks38.............................
18.3Removal38............................
19 Safetythermostat39...................
19.1Function39.............................
19.2Checks39.............................
19.3Removal39............................
20 Shortsparepartslist40................

2
1Overall information
1.1Overall View
Fan
Safety
thermostat
Main heat
exchanger
Burner
Ignition
electrodes
Gasvalve
Control
panel
Combustion
chamber
Automatic
air release
Pump
D.h.w.temp.
probe
D.h.w.
heatexchanger
Expansion
vessel
Detection
electrode
valve
D.h.w
flowswitch
Divertervalve
Airpressure
switch
Maincircuit
flowswitch
1.2Hydraulicdiagram
C
e
n
t
r
a
l
h
e
a
t
i
n
g
(
c
.
h
.
)
o
p
e
r
a
t
i
o
n
Domestichot water(d.h.w.)operation
C.h.
waterflow
C.h.
water return
D.h.w.
inlet
D.h.w
.
outle
t

3
2Generalaccess andemptying
hydraulic circuits
2.1Nomenclature
2
6
1
54
3
Fig.1
1Rightsidepanel
2Frontpanel
3Controlpanel lid
4Controlpanelcover
5Servicepanel
6Leftsidepanel
2.2Bodypanels
Warning:isolatetheboilerfromthemains
electricitysupplybeforeremovingany
coveringorcomponent.
Forthemostpartofthecheckandmaintenanceoper-
ationsitisnecessarytoremoveoneormorepanelsof
thecase.
Thesidepanelscanberemovedonlyaftertheremoval
ofthefrontpanel.
ToremovethefrontpanelremovescrewsA(Fig.2),lift
thepanelandremoveit.
A
Fig.2
ToremovethesidepanelsloosenthescrewsBandC
(Fig.3),bringthebaseofthepanelsawayfromthe
boilerandlift them,freeingthemfromthetophooks.
B
D
C
Fig.3--- bottomviewoftheboiler
2.3Controlpanel
Warning:isolatetheboilerfromthemains
electricitysupplybeforeremovingany
coveringorcomponent.
Togainaccess tothepartslocatedinsidethecontrol
panelproceedasfollows:
1Removethefrontpanelofthecase
2LoosenthescrewsBandC(Fig.3).
3RemovethescrewsD
4Movethelowerpartofthesidepanelsasindi-
catedinFig.4and pull thecontrolpanel.
Whencompletelypulledout,thepanelcanrotate
45°downwardstofacilitatetheserviceoper-
ationsontheinternalparts.

Generalaccess andemptyinghydraulic circuits
4
Fig.4
5RemovethescrewsEandremovetheservice
panel(Fig.5);
6Togainaccess tothe electronicregulationPCB
andthefull sequenceignitiondeviceremovethe
screwsFandremovethecontrolpanel lid
(Fig.5);
E
F
F
Fig.5
2.4Access tothesealedchamber
G
G
Fig.6
Togainaccess tothepartscontainedinthesealed
chamberitisnecessarytoremovethelidofthesealed
chamber.
Forthispurpose,removethefrontandsidepanelsof
thecase,removethescrewsGasindicatedinFig.6
andremovethelid.
2.5Emptyingtheprimarycircuit
1Closethec.h.circuitflowandreturncocksH.
(Fig.7).
H
H
J
Fig.7--- bottomviewoftheboiler
2Removethefrontandrightpanelsoftheboiler.
3OpenthedraintapI(Fig.8)untiltheboileriscom-
pletelyemptied.
4Closedraintapagainoncethe emptyinghas
beencompleted.
I
Fig.8
2.6Emptyingthed.h.w.circuit
5Closethed.c.w.inletcockJ(Fig.7);
6Openoneormorehotwatertapsuntiltheboiler
hasbeencompletelyemptied.

5
3Diagrams
3.1WiringdiagramM90D.24SM90D.28S
Ignition
electrodes
Flamedetection
electrode
bn=brown
bu=blue
bk=black
wh=white
rd=red
gy=grey
Externalcontrols
Electricsupply
Airpressure
switch
Timeswitch
123
t
bkbk
t
bk
bk bk
M
~
M
~
bk
bk
bk
bk
bk
bk
bk
terminalblock
terminalblock
gy bk
Pump
PrimarycircuitD.h.w.temperature
probeNTC
Three way
divertervalve
D.h.w.flow
switchflowswitch
C.h.temperature
probeNTC
Electronic
controlp.c.b.
Full sequence
ignitiondevice
gn=green
ye=yellow
rd
bu
whrd
bu
rd
bu
bn
bu
bn
bn
bu
bn
bu
bk bn bu
3 1 2
bk
gnye
bu
rd
bu bn
gnye gnye
gnye
gnye
gnye
gnye gnye gnye
gnye
bu bn
bn
bu
rd rd
wh
bu
rd
bu
rd
rd
gy
bn
bu
bu bu bn
bu
gy
rd
gnye
bn
bu
bk
rd
bk
wh
gn
NC
COM
NO
vt=violet
og=orange
gnye=green/yellow
bk
bu
bn
Wiringdiagramforboilerequipedwithfull sequenceignitiondevicetype:Bertelli&PartnersFM30
bk
bk
Modulating
gasvalve
gnye
gnye
bu
gnye
gy
bn
Safety
thermostatFan
M
~
ye
wh
gnye
vt
og
Safety
thermostat
Fan
M
~
bn
bu
gnye
bn bu
(alternativewiringcolours)

Diagrams
6
bn=brown
bu=blue
bk=black
wh=white
rd=red
gy=grey
gn=green
ye=yellow
vt=violet
og=orange
gnye=green/yellow
Ignition
electrodes
Flamedetection
electrode
Externalcontrols
Electricsupply
Airpressure
switch
Timeswitch
123
t
bkbk
t
bk
bk bk
M
~
M
~
bk
bk
bk
bk
bk
bk
bk
bk
bk
terminalblock
terminalblock
gy bk
Pump
Modulating
PrimarycircuitDHWtemperature
probeNTC
Three way
divertervalve
gasvalve
DHWflow
switchflowswitch
CHtemperature
probeNTC
Electronic
controlp.c.b.
Full sequence
ignitiondevice
gnye
gnye
bu
gnye
gyrd
bu
whrd
bu
rd
bu
bn
bu
bn
bn
bu
bn
bu
bk bn bu
3 1 2
rd
bu bn
bn
gnye
gnye gnye
gnye
gnye
gnye gnye gnye
gnye
bu bn
bn
bu
rd rd
wh
bu
rd
bu
rd
rd
gy
bn
bu
bu bu bn
bu
gy
rd
gnye
bn
bu
bk
rd
bk
wh
gn
NC
COM
NO
bk
bu
bn
bn
gnye
bu
Wiringdiagramforboilerequipedwithfull sequenceignitiondevicetype:Honeywell FPLD
Safety
thermostatFan
M
~
ye
wh
gnye
vt
og
Safety
thermostat
Fan
M
~
bn
bu
gnye
bn bu
(alternativewiringcolours)

Diagrams
7
3.2WiringdiagramM90D.24SR,M90D.28SR
Ignition
electrodes
Flamedetection
electrode
Safety
thermostat
ExternalcontrolsElectricsupplyFanAirpressure
switch
123
bk
t
bk
bk bk
M
~
bk
bk
bk
bk
M
~
bk
bk
terminalblockterminalblock
gy bk
Pump
Primarycircuit
flowswitch
C.h.temperature
probeNTC
Electronic
controlp.c.b.
Full sequence
ignitiondevice
rd
bu
bu
bn
bu
bn
bn
bu
bn
bu
bk
gnye
bu
rd
vt
bu
bn
bu bn
gnye gnye
gnye
gnye
gnye
gnye gnye gnye
gnye
bu bn
rd
bu
rd
rd
gy
bn
bu
bu bu bn
bu
gy
rd
gnye
ye
wh
gnye
vt
og
bn
bu
bk
NC
COM
NO
bn=brown
bu=blue
bk=black
wh=white
rd=red
gy=grey
gn=green
ye=yellow
vt=violet
og=orange
gnye=green/yellow
og
wh
ye
Wiringdiagramforboilerequipedwithfull sequenceignitiondevicetype:Bertelli&PartnersFM30
bk
bk
Modulating
gasvalve
gnye gnye
bu
gnye
gy
bn

Diagrams
8
bn=brown
bu=blue
bk=black
wh=white
rd=red
gy=grey
gn=green
ye=yellow
vt=violet
og=orange
gnye=green/yellow
Ignition
electrodes
Flamedetection
electrode
Safety
thermostat
ElectricsupplyFanAirpressure
switch
123
bk
t
bk
bk bk
M
~
bk
bk
bk
bk
bk
M
~
bk
bk
terminalblock
gy bk
Pump
Modulating
Primarycircuit
gasvalve
flowswitch
CHtemperature
probeNTC
Electronic
controlp.c.b.
Full sequence
ignitiondevice
gnye gnye
bu
gnye
gyrd
bu
bu
bn
bu
bn
bn
bu
bn
bu
rd
bu bn
bn
gnye
gnye gnye
gnye
gnye
gnye gnye gnye
gnye
bu bn
rd
bu
rd
rd
gy
bn
bu
bu bu bn
bu
gy
rd
gnye
ye
wh
gnye
vt
og
bn
bu
bk
NC
COM
NO
og
ye
bk
wh
vt
bu
bn
bn
gnye
bu
Wiringdiagramforboilerequipedwithfull sequenceignitiondevicetype:Honeywell FPLD