Buderus Logamax GB062-24 KDE H V2 User manual

Only for authorized service
technician !
Service Manual Gas Wallhung Boiler
Logamax Plus GB062
GB062 - 14....
GB062 - 24....
2017/01_PRM-M21_U. Demir

Content
Logamax Plus GB062
2
Content
1 Safety precautions and symbols . . . . . . . . . . . . . . . 3
1 Symbols . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
1.1 Safety precautions . . . . . . . . . . . . . . . . . . . . . 3
2 Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
2.1 Display . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
2.2 Before commissioning . . . . . . . . . . . . . . . . . . 4
2.3 Switching the appliance on/off . . . . . . . . . . . . 4
2.4 Setting the maximum flow temperature . . . . . 5
2.5 Setting the DHW temperature . . . . . . . . . . . . 5
2.6 Setting summer mode . . . . . . . . . . . . . . . . . . 5
2.7 Short operating overview . . . . . . . . . . . . . . . . 6
2.8 Product Type Description . . . . . . . . . . . . . . . . 6
3 Service menu settings . . . . . . . . . . . . . . . . . . . . . . . . 7
3.1 Operating the service menu . . . . . . . . . . . . . . 7
3.2 Service functions overview . . . . . . . . . . . . . . . 8
3.2.1 Menu 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
3.2.2 Menu 2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
3.2.3 Menu 3 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
4 Fault finding . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
4.1 Explanations of faults table . . . . . . . . . . . . . 15
4.2 Fault group definition . . . . . . . . . . . . . . . . . . 15
4.3 Faults and possible remedy steps . . . . . . . . 17
4.4 Faults that are not shown on the display . . . 40
5 Electrical values, gas conversion and boiler layout
41
5.1 Sensor (NTC) Values . . . . . . . . . . . . . . . . . . 41
5.1.1 Domestic hot water temperature Sensor . . . 41
5.1.2 Central Heating Flow Temperature Sensor,
Storage Tank Temperature Sensor . . . . . . . 41
5.1.3 Outdoor Temperature Sensor (7.747.026.229)
41
5.2 Gas conversion steps . . . . . . . . . . . . . . . . . . 42
5.3 Condens 2500W / CerapurCompact . . . . . . 43
5.3.1 GB062-24K.... . . . . . . . . . . . . . . . . . . . . . . . 43
5.3.2 Electrical values . . . . . . . . . . . . . . . . . . . . . . 44
6 Inspection and maintanance . . . . . . . . . . . . . . . . . 46
6.1 Safety instructions for inspection and
maintenance . . . . . . . . . . . . . . . . . . . . . . . . 46
6.2 Check the heat exchanger . . . . . . . . . . . . . . 47
6.3 Check the electrodes and clean the heat
exchanger . . . . . . . . . . . . . . . . . . . . . . . . . . 47
6.4 Cleaning condensate trap . . . . . . . . . . . . . . 49
6.5 Checkdiaphragm (flue gasnon-return device) in
the mixer unit . . . . . . . . . . . . . . . . . . . . . . . . 49
6.6 Checking the strainer in the cold water pipe 50
6.7 GB062..K.. (Combi) appliances: Check the plate
heat exchanger . . . . . . . . . . . . . . . . . . . . . . 50
6.8 Checking the expansion vessel . . . . . . . . . 50
6.9 Setting the heating system operating pressure
50
6.10 Removing automatic air vent valve . . . . . . . 51
6.11 Checking the gas valve . . . . . . . . . . . . . . . 51
6.12 Removing the gas valve . . . . . . . . . . . . . . . 51
6.13 Remove the heating pump . . . . . . . . . . . . . 52
6.14 Removing the motor of the 3-way valve . . . 52
6.15 Remove the heat exchanger . . . . . . . . . . . 52
7 Good to know . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53
7.1 Integrated Weather Dependet Function (WDC) -
Heat curve . . . . . . . . . . . . . . . . . . . . . . . . . . 53
7.2 Boiler Frost protection . . . . . . . . . . . . . . . . 53
7.3 Air purging in central heating mode . . . . . . 53
7.4 Air Pressure Switch (APS) . . . . . . . . . . . . . 53
8 Components . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54
8.1 Mixing unit . . . . . . . . . . . . . . . . . . . . . . . . . 54
8.2 Resonator & Burner . . . . . . . . . . . . . . . . . . 54
8.3 Venturi . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55
8.4 Circulation Pump (ErP pump) . . . . . . . . . . . 56

1
Safety precautions and symbols
Logamax PLus GB062 3
1 Safety precautions and symbols
1 Symbols
Signal words indicate the seriousness of the hazard in terms
of the consequences of not following the safety instructions.
•Caution indicates that minor damage to property could
result.
•Warning indicates that minor personal injury or serious
damage to property could result.
•Danger indicates that serious personal injury could
result. In particularly serious cases, lives could be at
risk.
Notes contain important information in cases where there is
no risk of personal injury or damage to property.
1.1 Safety precautions
If you smell gas
BTurn off gas service cook.
BOpen windows.
BDo not operate any electrical switches.
BExtinguish any naked flames.
BLeave the building and telephone the gas company and
authorized dealer from an outside phone.
If you smell fumes from the appliance
BSwitch off the appliance.
BOpen windows and doors.
BInform your heating engineer.
Fitting and Modifications
BFitting of the appliance or many modifications to be appli-
ance may only be carried out by a compotent perEND.
BFlue systens must not be modified in any way.
BIf the appliance has a type B.. flue system : Ventilation
openings in doors, windows and walls must not be sealed
or restricted. If draught-proof windows are installed, meas-
ures must be taken to ensure there is an adequate supply
of air to the appliance for combustion.
Inspection / Maintenance
BWe recommend take out a to have the system regulary
serviced in order to ensure that it functions reliably and
safely.
BOnly use original spare parts.
Combustible materials
BDo not store or use any combustible materials (paper, thin-
ners, paints etc.) in the vicinty of the appliance.
Combustion Air / Ambient Air
BKeep combustion air/ambient air free of corrosive sub-
stances (e. g. halogenated hydrocarbons which contain
chlorine or fluorine compounds). In this way corrosion can
be prevented.
Instructions to the customer
BExplain to the customer how the appliance works and how
to operate it.
BAdvise the customer that he / she must not make any mod-
ifications to the appliance or carry out any repairs on it.
Safety instructions in this document are identi-
fied by a warning-triangle symbol and are print-
ed on a grey background.
Notes are identified by the symbol shown on
the left. They are bordered by horizontal lines
above and below the text.

2Operation
Logamax Plus GB062
4
2Operation
Fig. 1 Hydraulic connections
1Siphon (condensation) Drain hose
2Heating flow valve (accessory)
3Domecti hot water qoutlet
4Gas valve (closed) (accessory)
5Drain hose
6Cold water valve (accessory)
7Heating return valve (accessory)
8Filling valve
2.1 Display
Fig. 2 Display
1Burner operation
2Fault display/standby mode display
3Heating mode active
4DHW heating active
5Summer mode active
6Service Mode
7Temperature display (in °C)
2.2 Before commissioning
BAdjust pre-charge pressure of expansion vessel to static
head of the heating system.
BOpen the automatic air vent valve (leave open).
BOpen all system radiator valves.
BOpen the cold water valve.
BOpen the cold water valve and one hot water tap until
water flows out.
BOpen the heating flow valve and heating return valve.
BFill the heating system to 1 - 2 bar and close the fill valve.
BBleed radiators.
BTop up heating system to pressure of 1 - 2 bar.
BCheck that the gas type specified on the type plate
matches that of the gas supply.
2.3 Switching the appliance on/off
Switching on
BStart the appliance at the standby key.
The display shows the heating water flow temperature.
Switching off/ standby mode
BShut down the appliance at the standby key.
Only the warning symbol continues to be displayed.
BIf the appliance is to be switched off for a longer period of
time: observe correct frost protection procedures.
Fig. 3
0 010 005 789-001
32
14 5 6 7
NOTICE: Commissioning without water will
destroy the appliance.
BOnly operate the appliance once it has been
filled with water.

2
Operation
Logamax PLus GB062 5
2.4 Setting the maximum flow temperature
The maximum flow temperature can be set between 40 °C
and 82 °C. The current flow temperature is shown on the
display.
BKeep pressing – until the symbol appears on the
display.
BPress OK.
The set maximum flow temperature is displayed.
BPress + or – to set the required maximum flow
temperature.
BPress OK to save the setting.
The display shows the current flow temperature.
You can find typical maximum flow temperatures in tab. 1.
When the burner is active in heating mode, the symbol
and the burner symbol appear on the display.
2.5 Setting the DHW temperature
The DHW temperature can be set between 35 °C and
approx. 60 °C.
BKeep pressing – until the symbol appears on the
display.
BPress OK.
The set DHW temperature is displayed.
BPress + or – to set the required DHW temperature.
BPress OK to save the setting.
The display shows the current flow temperature.
BWhen the burner is active in DHW mode, the symbol
and the burner symbol appear.
2.6 Setting summer mode
The heating circuit pump and consequently central heating
are switched off. The DHW and power supply for the heating
control unit and timer are retained.
To set summer mode:
BKeep pressing – until the symbol appears on the
display.
BPress OK.
The set maximum flow temperature is displayed.
BKeep pressing – until ... appears on the display.
BPress OK to save the setting.
is permanently displayed.
Additional instructions are contained in the operating instruc-
tions for the heating programmer.
The appliance has an anti-seizing function
which prevents the heating circuit pump and the
3-way valve seizing up following long periods of
inactivity.
The anti-seizing function remains active during
standby mode.
When selecting .., heating mode is disabled
( appears on the display, summer mode).
Flow temperature Sample application
..( symbol appears) Summer mode
Approx. 75 °C Radiator heating system
82 °C Convector heating system
Tab. 1 Maximum flow temperature
NOTICE:Heatingsystematriskthroughfrost.In
summer mode, only the appliance is protected
against frost.
BObserve frost protection measures where
there is a risk of frost.

2Operation
Logamax Plus GB062
6
2.7 Short operating overview
Fig. 4 Short operating overview
2.8 Product Type Description
GB Wall mounted condensiing gas boiler
062 Segmen
24 Nominal CH output in kW (14, 20, 24, ...kW)
KCombi version
DBooster for DHW (e.g. 28 kW)
HGas type (H = Natural Gas, L = LPG)
V2 Version2 : Energie Saving Pump
“IT” Country (e.g. Italy)
GB 062 - 24 K D H V2 IT
Tab. 2 Product type description

3
Service menu settings
Logamax PLus GB062 7
3 Service menu settings
3.1 Operating the service menu
The service menu enables the convenient adjustment and
checking of many appliance functions.
The service menu splits into three submenus:
•Menu 1, for setting level one service functions ( page 9)
•Menu 2, for setting level two service functions (page 12)
•Menu 3, for setting the appliance type and output
(page 14)
Selecting a service function
Calling up the service functions is different from one menu to
the next. For a description, see the beginning of each menu
overview.
BCalling up a menu:
–Menu 1 (‡page 8)
–Menu 2 (‡ page 12)
–Menu 3 (‡ page 14)
BPress + or – to scroll through the menu's service
functions.
Making a setting
BPress OK to switch to the service function.
The value flashes on the display.
BPress + or – to set the required value.
Saving a setting
BHold down OK until the selected service function appears
on the display.
Exiting the service function without saving settings
BPress standby.
The boiler returns to standard mode.
Restoring values to standard setting
To restore all values from service levels 1 and 2 to their
default settings:
BSelect service function 2.8.E in the second service menu
and save value 01. The appliance starts with the default
setting.
If you do not press a key for 15 minutes, the
service menu will be closed automatically.

3Service menu settings
Logamax Plus GB062
8
3.2 Service functions overview
3.2.1 Menu 1
To call up a service function in this menu:
BHold down “Back”, + and – at the same time until L.1 is
shown on the display.
BPress OK to make settings in menu 1.
BPress + or – to scroll through the menu's service
functions.
Service function Possible settings/display
1.A Maximum output for cental heat-
ing Some gas supply utilities charge a basic rate based on output.
The output can be limited to the specific heat demand between the mini-
mum rated output and maximum rated output.
Default setting is the maximum rated output.
BSet the output in percent (%).
BMeasure the gas flow rate and compare it with the information from
the setting tables. If they do not match, change the setting.
1.b Maximum output
(DHW) The output can be limited to the specific heat demand between the mini- mum rated output and maximum rated output.
Default setting is the maximum rated output for DHW.
BSet the DHW output in percent.
BMeasure the gas flow rate and compare it with the information from
the setting tables. If they do not match, change the setting.
1.E Pump mode Pump mode (pump run while burner off)
0 = as mode 2, but automatic selection
of mode 4
if outdoor sensor detected
1 = off after pump overrun
2 = depends on room thermostat
3 = depends on outdoor control
2.b Maximum flow temperature The maximum flow temperature can be set to between 30 °C and 82 °C.
Default setting : 82.
2.C Venting function The venting function can be activated after maintenance.
The following settings are possible:
•00: Venting function off
•01: Venting function is switched on and after completion automatically
reset to 00
•02: Permanent on.
Default setting : 00.
Tab. 3 Menu 1

3
Service menu settings
Logamax PLus GB062 9
2.d Thermal disinfection of the DHW
cylinder (System boiler) •0: Switched off
•1: Switched on
This service function activates the heating of the DHW cylinder to 75 °C.
BImplement thermal disinfection as described.
Thermal disinfection will not be displayed.
Thermal disinfection terminates after the water has been held at
75 °C for 35 minutes.
2.F Operation Mode volatile With this service function, you can temporarily change the appliance
operating mode.
The following settings are possible:
•0: Standard operation; the appliance runs according to controller
specifications.
•1: The appliance runs for 15 minutes at the set minimum output. After
15 minutes, the appliance switches to standard mode.
•2: The appliance runs for 15 minutes at maximum output. After
15 minutes, the appliance switches to standard mode.
Default setting : 0.
2.J Central heating / Storage tank
alternating mode (system boiler) Anternating mode for 10 minutes betweens both mode.
Setting range: 0 - 1
Default setting : 0 minutes.
3.A Automatic ant-cycle mode 0 : 0ff, 1 : on (installation with weather depanded controls)
Default setting : 0
3.b Time interval for starting and
stopping (anti-cycle) the burner
(in CH mode)
The time interval determines the minimum delay between the burner
stop and restart (only active, if 3.A = 0).
Setting range: 1 to 10 minutes.
Default setting : 3 minutes.
3.C Temperature differential for
stopping and restarting the
burner (Hysterisis) (via CHNTC)
The temperature differential determines the level by which the flow tem-
perature must drop below the set flow temperature before the drop is
interpreted as a heat demand. Settings in 1 K steps are possible.
The temperature differential can be selected between 0 and 10 K.
Default setting : 5 K.
3.d Min output in CH/ tank mode (%) Setting range : 20 - 80
3.E The period activeting keep hot
function (comfort mode) (Combi
version)
Setting range: 20 - 60 minutes.
Default setting : 20 minutes.
3.F Domestic hot water standby
time after tapping during CH
mode (Combi version)
Heating mode is disabled for this period of time following DHW heating.
Setting range: 0 - 30 minutes.
Default setting : 1 minutes.
Service function Possible settings/display
Tab. 3 Menu 1

3Service menu settings
Logamax Plus GB062
10
4.b max pre heat temperature for
comfort function (combi) max DHW pre heat temperature for comfort function.
The following settings are possible:
•40 … 65 ºC
Default setting : 62 º
4.E Boiler type It will be detected automaticly of DHW or tank NTC and shown in display.
Possible values:
•0 : only heating
•1 : Combi
•2 : Tank with NTC (system boiler)
4.F Siphon filling mode Possible settings:
•0 : Off
•1 : On with min output (factory setting)
•2 : On with changed min CH output
5.A Reset service reminder If you see this symbol, you can reset to “0” after inspection.
5.b Fan overrun time Time intervall for the maintanence (month)
0 = Off
1 .. 72 = Time (Month)
5.F Inspection intervall If you see this symbol, you can reset to “0” after inspection.
6.A Calling up the last fault saved The function enables you to retrieve the last fault stored.
The service function is reset at 00.
6.C Setpoint value of the tempera-
ture from EMS-BUS
6.d Current turbine flow rate (combi) The current turbine flow rate is displayed.
Possible displays are:
•0.0. - 20.0. l/min
7.A Backlight of LCD The following settings are possible:
•00: Off
•01: on
Default setting : 00.
7.C Minimum DHW flow rate DHW heating is activated if amounts above this value are drawn off.
The following settings are possible (x 0,1):
•25 … 50 litres per minute
Default setting : 25 l/min.
Service function Possible settings/display
Tab. 3 Menu 1

3
Service menu settings
Logamax PLus GB062 11
7.E Building dry function The building drying function of boiler doesn’t corresponds to the dry func-
tion of the weather depended controls.
In case of activation of this function, DHW and chmniy sweep function is
no tpossible. During this period you can the symbol (dr) in display.
The following settings are possible:
•00: Off
•01: On
Default setting : 00.
P.0 Activiation of integrated WDC
(Weather Depended Controls)
function and set point of sum-
mer switch set-temperatur
•0: WDC function is Off
•1...30: Temperaturlimit for summer and WDC activiation
Default setting : 0.
P.1 Setpoint B of the heat curve for
WDC 20 ... 50 : Flowtemperature (set point)
P.2 Setpoint A of the heat curve for
WDC 50.. 88 ... 90: Flowtemperature (set point)
P.6 LCD Backlight (Permanent) •0: Off
•1: On
Default setting : 0.
P.7 Domestic hot water comfort •0: Eco mode
•1: Comfort mode
Default setting : 0.
Service function Possible settings/display
Tab. 3 Menu 1

3Service menu settings
Logamax Plus GB062
12
3.2.2 Menu 2
To call up a service function in this menu:
BHold down “Back”, + and – at the same time until L.1 is
shown on the display.
BPress – until L.2 is shown on the display.
BPress OK to make settings in menu 2.
BPress + or – to scroll through the menu's service
functions.
Service function Possible settings/comments/displays
8.A Software version The current software version is displayed.
8.b Display soft code number
8.C Display internal status code internal parameter
8.d Display internal fault code internal parameter
8.E Returning the appliance to its
standard settings This service function enables you to reset the appliance to its standard set- tings.
Setting 00.
8.F Ignition test (permanent) •0 = Off
•1 = On
9.A Permanent operating mode This function permanently sets an operating mode.
The following settings are possible:
•0: Standard operation; the appliance runs according to controller specifi-
cations.
•1: The appliance runs at minimum output.
•2: The appliance runs at maximum output.
Default setting : 0.
9.b Actual fan speed Actual fan speed in Hz
9.E Signal turbine delay
(Combi version) Through spontaneous pressure change in the water supply, the flow meter
(turbine) can signal that water is being drawn off.
This means the burner starts briefly although no water is drawn off.
The turbine signal delay can be set from 1 to 8. One step corresponds to
0.25 seconds.
Default setting : 4 (0,25 seconds).
9.F Heating circuit pump overrun time The pump overrun time is started by the control system at the end of the
heat demand.
The following settings are possible:
•1 to 10: overrun time in minutes (steps of 1 minute)
Default setting : 3 minutes.
A.A Temperature at flow temperature
sensor This service function allows you to display the temperature at the flow tem- perature sensor.
Tab. 4 Menu 2

3
Service menu settings
Logamax PLus GB062 13
A.b DHW temperature (Combi version) This service function allows you to display the DHW temperature.
A.C Temperature at cylinder tempera-
ture sensor (system version) This service function allows you to display the temperature in the DHW cyl- inder.
b.F DHW heating delay (solar mode) Heating will be suppressed until the DHW temperature sensor detects that
the water preheated by solar energy has reached the required outlet tem-
perature. Set the heating delay in accordance with system conditions.
The start delay can be set between 0 - 50 seconds.
Default setting is 0 (disabled).
F.2 Ionisation current •with running boiler (burner) :
–> 20 = OK
–< 20 = faulty
F.3 Permanent operation mode (chim-
niy sweeper) Possible displays are:
•0: normal operation mode
•1: operation in max output for 15 minutes
Service function Possible settings/comments/displays
Tab. 4 Menu 2

3Service menu settings
Logamax Plus GB062
14
3.2.3 Menu 3
To call up a service function in this menu:
BHold down “Back”, + and – at the same time until L.1 is
shown on the display.
BPress – until L.3 is shown on the display.
BPress OK to make settings in menu 3.
BPress + or – to scroll through the menu's service
functions.
Code List for the Service function E.1 :
Service function Possible settings/comments/displays
E.1 Appliance type, output, DHW heat-
ing (soft code) This service function allows you to adjust the control unit to the appliance output and the type of DHW heating (see table below regarding the code list
for this service function). This is only necessary when the control unit is
replaced.
F.1 Gas Type With this service functlon is changed the gas type.
BTo change the actual gas type, press + and - button together until the
scroll up/down symbol is shon in display.
•0: Naturalgas
•1 : Liquidgas (LPG)
Tab. 5 Menu 3
Country Definition of Appliance Soft
Code
TR (Turkey) GB062-22 KD ... 21
IT (Italy) GB062-24 (K) ..... 22
GB062-24 KD ... 23
GB062-14 ... 24
AT (Austria) GB062-24 (K) ... 22
PL (Poland) GB062-24 (K) ... 27
GB062-14 ... 29
RO (Romania) GB062-24 .... 27
GB062-24 KD .... 28
GR (Greece) GB062-24 .... 27
GB062-24 KD ... 28
SK (Slovakai) GB062-24 (K) .... 27
GB062-14 .... 29
CZ (Czech
Repuclic) GB062-24 (K) .... 27
GB062-14 .... 29
BE (Belgium) GB062-24 KDE .... 28
GB062-24 KD ... 26
GB062-14 .... 30
GB062-24 .... 25
Tab. 6 Code table for the service function E.1
This parameter is only available/active for the
spare part change. By origin PCB (electronic
card) this function is only visible.
This parameter should be adjusted by each
PCB-Change regarding the TTNr. (Codelist is in
PCB included).

4
Fault finding
Logamax PLus GB062 15
4 Fault finding
4.1 Explanations of faults table
Each title of the table shows the error code in the display and
at the same time the cause of the error in general. To repair
any possible fault in the device, follow the troubleshooting
steps in order until the fault is detected.
4.2 Fault group definition
Shown failures are divided in diffrent category :
•RUN: Fault does not block the burner.
•WAIT: Fault blocks the burner until faults removes.
•BLOCK : Fault blocks the burner until mains supply off
(volatile lockout).
•LOCK: Faults blocks the burner (nonvolatile lockout).
•RESET : Fault causes a board reset.
•HIST : Fault code is only stored in EEPROM fault history.
Failure Code Cause
Code Failure
Category Failure description Page
CL 324 RUN Hot water temperature sensor is faulty. 17
5L 323 RUN BUS-Communication fault. 19
CP 326 RUN WBC...D appliances (system boiler): Cylinder/tank temperature sensor. 20
3Y 334 WAIT The differential pressure switch is open before ignition (during self
check) (only high modulation version). 20
3C 217 WAIT Fan not running. 20
2E 207 WAIT Heating system charge pressure is too low. 23
8Y 232 WAIT External switching contact triggered. 24
4Y 223 WAIT Flow temperature sensor (CH-NTC) faulty. 26
4C 224 LOCK - Heat exchanger temperature limiter or flue gas temperature limiter has
tripped.
- The differential pressure switch does open when the fan runs (after
ignition) (only high modulation version).
30
6A 227 LOCK Flame not detected. 30
EC 256 LOCK Internal fault. 35
6C 228 LOCK Flame detected even when the burner is switched off. 36
6C 308 LOCK After switching gas off : Flame is detected.37
EP 327 LOCK The “OK” button was actually pressed for at least 5 seconds (= reset). 38
WAIT Gradient Monitoring. 43
P78 WAIT Appliance code not defined. 44
Tab. 7 Failure codes shown in display

4Fault finding
Logamax Plus GB062
16
Faults that are not shown on the display
Fault description Page
Combustion noise too loud; rumbling noises 42
Water circulation noises 44
Heat-up lasts too long. 45
Flue gas readings incorrect; CO content too high. 47
Ignition too strong, or poor. 47
Condensate in air box. 47
DHW outlet temperature not reached. 47
DHW volume (flowrate) not reached. 47
No function, the display remains dark. 47
Tab. 8

4
Fault finding
Logamax PLus GB062 17
4.3 Faults and possible remedy steps
CL
Hot water temperature sensor (DHW-NTC) is faulty.
Step Remedy
1. Check the hot water temperature sensor for
breaks or short CLcircuits.
BSwitch off the boiler.
BRemove the Socket of NTC.
BMeasure the electrical resistance of DHW-
NTC (in Ω) (see NTC tables).
Is the resistance value correct ?
yes: --> 2.
no: BChange the Sensor.
BSwitch on the boiler.
CL on display ?
-->2.
2. BSwitch off the boiler.
BCut the main voltage supply.
BCheck the soft code via Service function
E.1.
Is the code correct ?
yes BSwitch on the boiler.
CL on display ?
-->3.
no: BCorrect the right boiler type co5Lde.
CL on display ?
-->3.
3. Check the cables for damages.
BSwitch off the boiler.
BIn case of DHW-NTC is changed :
- Remove the NTC socket.
- Measure the NTC resistance.
- Connect the socket again.
BRemove the big socket (20 Pole) on PCB.
BMeasure the NTC resistance (Ω) on big
socket (PCB side).
Are measured resistance values on NTC
and socket side different ?
yes: BChange the cable haarness.
BSwitch on the boiler.
CL on display ?
-->4.
no: --> 4.
4. Electronic board (PCB) is defect. BSwitch off the boiler.
BCut the main voltage supply.
BChange the electronic board (PCB).
BSwitch on the main voltage supply.
BSwitch on the boiler.
BEND

4Fault finding
Logamax Plus GB062
18
5L
BUS-Communication fault
Step Remedy
1. BSwitch off the boiler.CP
BCut the main voltage supply.
BCheck the connection terminals at
controls and boiler.
Are the connection terminals dirty or
corroded ?
yes: BClean the connection terminals.
BConnect the cable again.
BSwitch on the boiler.
5L on display ? --> 2.
no: BRemove the control (thermostat) and check the
error again. If there is no error, check the control
(thermostat). Change if necessary, change it.
BSwitch on the boiler.
--> 2.
2. BCheck the connections between the
control (thermostat) and the boiler.
Is resistance very high ?
yes: BSwitch on the boiler.
BCut the main voltage supply.
BChange the connection cable between boiler and
control (thermostat).
BSwitch on the boiler.
5L on display ? --> 2.
no: --> 3.
3. Electronic board (PCB) is defect. BSwitch off the boiler.
BCut the main voltage supply.
BChange the electronic board (PCB).
BSwitch on the main voltage supply.
BSwitch on the boiler.
BEND

4
Fault finding
Logamax PLus GB062 19
CP
System boiler: Cylinder / tank temperature sensor.
Step Remedy
1. Check the tank temperature sensor for
breaks or short circuits.
BSwitch off the boiler.
BRemove the NTC of terminal.
BMeasure the electrical resistance of Tank-
NTC (in Ω) (see NTC tables).
Is the resistance value correct ?
yes: --> 2.
no: BChange the Sensor (NTC).
BSwitch on the boiler.
CP on display ?
-->2.
2. BSwitch off the boiler.
BCut the main voltage supply.
BCheck the soft code and boiler type via
Service function E.1 and 4.E.
Is it correct ?
yes BSwitch on the boiler.
CP on display ?
-->3.
no: BCorrect the right boiler type code.
CP on display ?
-->3.
3. Check the NTC cables.
BIs there any damages or short circuit or
break ?
yes: BChange the cable/NTC.
BSwitch on the boiler.
CP on display ?
-->4.
no: --> 4.
4. Electronic board (PCB) is defect. BSwitch off the boiler.
BCut the main voltage supply.
BChange the electronic board (PCB).
BSwitch on the main voltage supply.
BSwitch on the boiler.
BEND

4Fault finding
Logamax Plus GB062
20
3Y
The differential pressure switch is open before ignition (during self check) (only high modulation version).
Steps Remedy
1. Check the contacts of diff. pressure
switch.
BSwitch off the boiler.
BCheck the connection of diff. pressure
switch.
BMeasure the circuit with a instrument.
The circuit /contact should be closed.
Is the contact /circuit open ?
yes: BChange the diff. pressure switch.
BSwitch on the boiler.
3Y ? -->2.
no: BConnect the diff. pressure switch again.
BSwitch on the boiler.
-->2.
2. Check the silicon hose.
Is there any blockage or stuck on silikon
hose ?
yes: BSwitch off the boiler.
BChange the silicon hose or correct the stuck.
BSwitch on the boiler.
3Y ? -->3.
no: -->3.
3. Check the low voltage cable for damages
or open circuit.
BSwitch off the boiler.
BRemove the connection of PCB and
measure the circuit of the diff.
pressure switch.
BMeasure the circuit with a instrument.
The circuit /contact should be closed.
Is the contact /circuit open ?
yes: BChange the low valtage cable.
BSwitch on the boiler.
3Y ? --> 4.
no: --> 4.
4. Electronic board (PCB) is defect. BSwitch off the boiler.
BCut the main voltage supply.
BChange the electronic board (PCB).
BSwitch on the main voltage supply.
BSwitch on the boiler.
BEND