Viessmann 200 CI2 Service Instructions

Skylar Kaczanowski

Sep 12, 2023

CI2 Technical Service Guide Highlights

Commissioning:

Commissioning the System with the Commissioning Assistant

Single boiler system
1.    Open the gas shut-off valve.
2.         If the boiler has not been switched on yet: Turn on the ON/OFF switch.
The commissioning assistant starts automatically. If the boiler has already been switched on:
See chapter “Calling up the commissioning assistant at a later point”, page 15.
3.    Commission the boiler and follow the commissioning assistant. See the overview below.
Note: All PlusBus subscribers must be connected and switched on.
Note: Depending on the type of boiler, the accessories connected and other settings, not all menu points will be displayed.
Note: After the commissioning assistant has finished, check that the actuators are connected and operating correctly. Start the actuator test,
refer to page 53.

WARNING

Escaping flue gas can cause life threatening poisoning from carbon monoxide.
To prevent flue gas escaping, only use the condensate drain with a trap.
Ensure there are no leaks from the flue system.

Commissioning assistant sequence

Explanations and references

Commissioning

Language

Factory setting: English

With programming unit

If commissioning is to be carried out at the programming unit of the boiler.

With software tool

The boiler automatically switches on the WiFi access point.
Further commissioning steps according to the instructions of the software tool used (e.g. “Viguide”)
Note: Apps for commissioning and service are available for iOS and Android devices.
Cascade systems can only be commissioned using the software tool.

Units of measurement

Date and time

Set the current time.

Operating mode

Weather-compensated operation
The outside temperature sensor must be connected. Constant operation
Operation with constant supply temperature

Gas type

If operating with LPG, switch to “LPG” (the delivered condition is Natural Gas)

Flue system type

Single connection
Only one boiler is connected to the flue system (factory setting). Multiple connections
Several boilers are connected to the flue system (common venting).

Flue length adjustment

Specification of the effective flue and ventilation air length. To determine the effective flue and ventilation air length, see page 19, chapter “Matching the burner output to the flue system”.

If no further settings are to be performed, the commissioning assistant can now be closed.

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Commissioning

Vitocrossal 200 CI2 Service

Commissioning the System with the Commissioning Assistant (continued)

Commissioning assistant sequence

Explanations and references

System scheme

Heating circuit 1

Heating circuit without mixing valve

Heating circuit 2, 3 ...

Heating circuits with mixing valve

DHW
Not available
Tank with one sensor Tank with one sensor and DHW recirculation pump
Tank with temperature switch Tank with temperature switch and DHW recirculation pump

Settings for DHW heating according to the system components System without DHW heating
System with DHW tank with 1 tank temperature sensor
System with DHW tank with 1 DHW tank temperature sensor and DHW recirculation pump
System with DHW tank with temperature switch (such as an aquastat)
System with DHW tank with temperature switch, (such as an aquastat) and DHW recirculation pump

Low loss header/buffer tank Not available
Low loss header, heating only DHW heating upstream of low loss header
DHW heating downstream of low loss header
Buffer tank, heating only DHW heating upstream of buffer tank
DHW heating downstream of buffer tank

Settings for the consumer circuits according to the system components There is no low loss header or heating water buffer tank in the system. System with low loss header, without DHW heating
DHW heating with e.g. separate DHW tank connected upstream of the low loss header
DHW heating with e.g. separate DHW tank connected downstream of the low loss header
System with heating water buffer tank, without DHW heating
DHW heating with e.g. separate DHW tank connected upstream of the heating water buffer tank
DHW heating with e.g. separate DHW tank connected downstream of the heating water buffer tank

Heating zone/safety input
Heating zone 1

Not available or temperature controller or safety device 1 Not available or temperature controller or safety device 2
Not available or temperature controller or safety device 3

Heating zone 2
Heating zone 3
(based on boiler application type)

Vitocrossal 200 CI2 Service

Commissioning

Commissioning the System with the Commissioning Assistant (continued)

Commissioning assistant sequence

Explanations and references

Floating contact: Function selection plug 96

If a contact has been connected to plug 96.

No function
External demand, DHW circulation pump External demand
(based on boiler application type) External blocking
Heat demand
(based on boiler application type)

Push button function, DHW recirculation pump runs for 5 min.
Boiler demand with adjustable target supply temperature
(parameter 528.0) and target primary pump speed (parameter 1100.2) Call for heat is shown in the display/menu as “Heating zone 4”.

EM-EA1 (DIO): Function selection
(based on boiler application type)

If an EM-EA1 extension (DIO electronics module) is connected as a function extension.

Functions

Selection of the connected function according to the table in the EM-EA1 exten- sion installation instructions.

Remote control units

Set the type of remote control and subscriber no. as assignment to the respective heating circuit. Up to 4 heating circuits can be assigned to one remote control unit. It is not possible for several remote controls to act on one heating circuit.

“Primary pump”

No pump
Boiler circuit pump Boiler circuit pump

On/off control
0 - 10V modulation control

Maintenance

Interval in burner hours run until next maintenance

Interval adjustable in steps of 100 h.

Interval until next maintenance

Interval adjustable to 3, 6, 12, 18 or 24 months.

Multi boiler system
The lead boiler must be commissioned using the Viguide app (service layer).
Note: Commission the lead boiler first, then the lag boilers.
The lag boiler is numbered by manually setting the subscriber number (ID).
Always enter the ID number consecutively and without gaps!
After this, the respective boiler has to be commissioned using the Viguide app.
Follow the instructions in the app and establish a
connection between the lead boiler and the Viguide app.

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Commissioning

Vitocrossal 200 CI2 Service

Commissioning the System with the Commissioning Assistant (continued)

Commissioning assistant sequence

Explanations and references

Commissioning

Viguide function type:

Lead 1 (1) Cascade lead without heat provides cascade functionalities to connected lag devices. Does not support DHW or heat supply by itself.
Lead 1 (1) Cascade heat lead provides cascade functionalities to its own and connected lag devices. Does not support DHW supply or global DHW supply.
Lead 1 (1) Cascade heat DHW lead provides cascade functionalities to its own and connected lag devices and provides local DHW production.
Lag 1-15 (2-16) Heat lag is a device controller that provides lag heating device functionalities
Lag 1-15 (2-16) Buffer lag to be applied for multivalent systems, e.g. CHP Lag 1-15 (2-16) DHW lag is a lag device that provides only support in DHW production – hydraulically separated
Lag 1-15 (2-16) Backup heater is a lag device that is taken out of the cascade sequence as a fall-back solution, central heating only..

Viguide cascade member se- quencing strategy:

1.1 Dynamic strategy – fixed first dynamic sequence of the cascade members with manually configured fixed first device in sequence
1.2 Dynamic strategy – fixed last dynamic sequence of the cascade members with manually configured fixed last device in sequence
1.3 Dynamic strategy – runtime optimization dynamic sequence of the cascade members with runtime optimization of the cascade members
2 Manual mode – manual mode of the cascade members with fixed configured sequence.
In general the whole cascade is supply temperature-controlled:
A particular supply temperature is requested from all cascade members.

Commissioning assistant sequence

Explanations and references

Viguide lead boiler commissioning:

Units:
Gas type Altitude Filling Venting
Safety functions on MZIO; low gas pressure via ZI2; high gas pressure via ZI3). Central heating pump mode (auto or modulation controlled pump).
Set up the combustion air interface. Flue gas sensor test.
Time and auto summer/wintertime.
DHW function: one-time load, hygiene function and scald protection. Supported number and type (direct/mixed/none) of heating circuits. Number of TT circuits.
Function of TT circuits.
Control type (weather-compensated/constant control) – if weather- compensated, then the setting “heating and TT circuit” or only “heating” without TT circuit is selectable.
Setup of internet connection
If weather-compensated, then source of valid outside air temperature is selectable. If constant mode control type:
a) Constant flow control for heating circuits.
b) Constant flow control with data interface for gateway/building automation system for heating circuits.
c) Fixed temperature supply to TT zones with TT circuits is selectable.

Vitocrossal 200 CI2 Service

Commissioning

Commissioning the System with the Commissioning Assistant (continued)

Commissioning assistant sequence

Explanations and references

Viguide lag boiler commissioning:

Units:
Gas type Altitude Filling Purging
Safety functions on MZIO; low gas pressure via ZI2; high gas pressure via ZI3). Central heating pump mode (auto or modulation controlled pump).
Set up the combustion air interface. Flue gas sensor test.

Viguide service layer lead device:

Emissions test mode Actuator test mode Min. partial load Max. partial load
System configuration:
General – device/boiler – DHW – heating circuit 1/2/3/4 - TT circuits Diagnosis:
General – device/burner – DHW – heating circuit - TT circuits

Viguide service layer lag device:

Emissions test mode Actuator test mode Min. partial load Max. partial load
System configuration: General – device/boiler
Diagnosis:
General – device/burner

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Switching internet connectivity on/off
The boiler equipped with an integrated communication module, the communication module supports internet connectivity via WiFi and LAN.
The internal communication module supports commissioning of the boiler with the “Viguide app”,.
The access information required to establish the connection is stored in the form of an access code with “WiFi symbol”. The access information is located in triplicate on the back of the programming unit.
Remove the WiFi access labels from the clear plastic pocket located on the front of the boiler near the main power switch. For commissioning, affix one of the WiFi access labels to each of the following locations:
- Free space on the boiler jacketing
- Designated space in the Service Instructions
- Designated Space in the Operating Instructions
Operating instructions

Switch on the WiFi connection or LAN and establish a connection to the router.
Activating the internet connection:
Calling up the commissioning assistant at a later point If you need to continue commissioning later, the commissioning assistant can be reactivated at any time. Tap the following buttons:
1.
2.    “Service”
3.    Enter password “viservice”.
4.    Confirm with .
5. “Commissioning”

Heating Curve Adjustment:

Example for outdoor temperature 5°F (−15°C)
A. Underfloor heating system, slope 0.2 to 0.8
B. Low temperature heating system, slope 0.8 to 1.6
C. Heating systems with a boiler water temperature in
excess of 167°F (75°C), slope greater than 1.6

Tap the following buttons:
1.
2.    “Heating”
3.    Select “Heating circuit 1” or “Heating circuit ...” for the required heating circuit.
4.    “Heating curve”
5.    Set the heating curve according to the requirements of the system using “Slope”+/– or “Shift” +/–.
6.        to confirm
Heating curve
The heating curves represent the relationship between the outside temperature and the supply temperature.
Simplified: The lower the outside temperature, the higher the supply temperature must be in order to reach the target room temperature.
Factory settings: Slope = 1.4
Shift = 0
Note: If heating circuits with mixing valve are present in the heating system: The supply temperature of the boiler is one differential temperature higher than the supply temperature for the heating circuits with mixing valve. Differential temperature in factory setting 14°F (8 K).
The differential temperature is adjustable using the following parameters:
Heating circuit 2: Parameter 934.5
Heating circuit 3: Parameter 935.5
Heating circuit 4: Parameter 936.5

Gas Pressure Supply:

Supply pressure for NG/LPG

1. Start the burner.
Note: Switch the burner to maximum heating output.
For this, activate the emissions test switch at the
boiler control unit.

2. Measure the supply pressure (running pressure).
Use suitable measuring instruments calibrated with
a minimum resolution of 0.04 “w.c. Value must be as
per the chart below:

Supply pressure with:

Corrective action

Natural gas

Liquid propane gas

under 4 ”w.c.

under 10 ”w.c.

Do not attempt adjustment. Call local gas utility

4 to 14 “w.c.

10 to 14 ”w.c.

Start up boiler.

over 14 ”w.c

over 14 ”w.c.

Do not attempt adjustment. Call local gas utility to decrease pressure. Boiler valve must not be exposed to pressure over 14 ”w.c.

Note: The supply pressure should be between 4 “w.c.
and 14 ”w.c. for NG and 10” w.c. to 14” w.c.
for LPG. The gas pressure switch for the inlet
pressure test/check is factory set to 4 ”w.c.
Never alter this setting.

3. Record the actual value in the maintenance record
(on page 83).

4. Close the gas shut-off valve.

5. Remove the pressure tester and close test nipple .

Error Codes For CI2 Series Boiler:

Vitocrossal 200 CI2 Service ^{Troubleshooting}
Calling up Fault Messages from the Fault Memory (message history)

The 10 most recent faults (including those remedied) and maintenance messages are saved and can be called up. Faults are sorted by date.
Tap the following buttons: 1.   “        “
2.   “Service”
3.   Enter password “viservice”. 4.
5.   “Message history”
6.   “Faults” to call up saved fault messages.
7.    If you wish to delete the list, tap .
8.   Confirm with   .
Fault Messages
Note: Fault messages dependent on boiler equipment level, and connected accessories.

Displayed fault code

System characteristics

Cause

Measures

F.7

No DHW heating

Lead break, tank temperature sensor

Check DHW setting in the commissioning assistant and correct if necessary.
Check tank temperature sensor.
Measure voltage at sensor input on electronics module. Target value:
3.3V– with sensor disconnected Replace faulty component if necessary.

F.8

No DHW heating

Short circuit, tank temperature sensor

Check tank temperature sensor. Replace faulty component if necessary.

F.13

Regulates as if the outside temperature were 32°F (0°C).

Lead break, outside temperature sensor

Check the operating mode setting in the commissioning assistant and correct if necessary.
Check outside temperature sensor and connection to sensor.
Measure voltage at sensor input on electronics module. Target value:
3.3V– with sensor disconnected Replace faulty component if necessary.

F.14

Regulates as if the outside temperature were 32°F (0°C).

Short circuit, outside temperature sensor

Check outside temperature sensor and connection to sensor. Replace faulty components if necessary.

Troubleshooting

Vitocrossal 200 CI2 Service

Fault Messages (continued)

Displayed fault code

System characteristics

Cause

Measures

F.29

Regulates without supply temperature sensor for low loss header.

Lead break, low loss header sensor

Check low loss header setting in the commissioning assistant and correct if necessary.
Check supply temperature sensor, low loss header.
Measure voltage at sensor input on electronics module. Target value:
3.3V– with sensor disconnected

F.30

Regulates without supply temperature sensor for low loss header.

Short circuit, low loss header sensor

Check supply temperature sensor, low loss header. Measure voltage at sensor input on electronics module.
Target value:
3.3V– with sensor disconnected

F.49

Burner in a fault state

Lead break, flue gas temperature sensor

Check flue gas temperature sensor. Reset the boiler.

F.50

Burner in a fault state

Short circuit, flue gas temperature sensor

Check flue gas temperature sensor. Reset the boiler.

F.57

Normal operation without room influence

Lead break, room temperature sensor

Check remote control setting in the commissioning assistant and correct if necessary.
Check plug and cable of external room temperature sensor, heating circuit.
If no external room temperature sensor installed, replace Vitotrol programming unit.

F.58

Normal operation without room influence

Short circuit, room temperature sensor

Check plug and cable of external room temperature sensor, heating circuit.
If no external room temperature sensor installed, replace Vitotrol programming unit.

F.59

Burner locked out

Power supply, low voltage

Check mains voltage.
If voltage is correct and the fault occurs repeatedly, replace the fan unit.

F.62

Burner in a fault state

High limit safety cut-out has responded.

Check heating system fill level.
Check pre-charge pressure in diaphragm expansion tank. Adjust to required system pressure.
Check whether flow rate is sufficient (flow sensor and circulation pump).
Reset the boiler.

F.63

Burner in a fault state

Flue gas temperature limiter has responded.

Check heating system fill level.
Check pre-charge pressure in diaphragm expansion tank.
Adjust to required system pressure.
Check whether flow rate is sufficient (flow sensor and circulation pump).
Vent the system.
Reset the boiler once the
flue system has cooled down.

Vitocrossal 200 CI2 Service

Troubleshooting

Fault Messages (continued)

Displayed fault code

System characteristics

Cause

Measures

F.64

Normal operation; burner restarts

Flame loss during stabilization or operating phase.

Check ionization electrode (replace if necessary): Check the electrode for contamination and clearance to the burner gauze assembly.

F.65

Burner in a fault state

Flame signal is not present or insufficient at burner start.

Check ventilation air/flue system and condensate drain; clean if necessary.
Check ionization electrode and connecting cable.
Check the ignition.
Check the connecting cables between the ignition module and ignition electrode; check the ignition electrode for clearance, contamination and broken insulation.

F.67

Burner in a fault state

Ionization current lies outside the permissible range

Check gas supply (gas pressure), check gas solenoid valve and inlet strainer.
Check ionization electrode:
Clearance to burner gauze assembly
Check electrode/burner gauze assembly for contamination.
If specified measures don’t help, replace fan unit.
Reset the boiler.

F.69

Burner in a fault state

Ionization current lies outside the permissible range

Check ionization electrode:
Check whether insulation block is touching electrode ceramic.
Check gas solenoid valve: Activate “Minimum heating output” for approx. 4 min in actuator test.
If this causes a fault to occur, replace BCU burner control unit.
In the actuator test, switch from “Minimum heating output” to “Maximum heating output”. If this fault occurs during modulation, check the intake screen for contamination.
Replace the fan unit if necessary.

F.71

Burner in a fault state

Fan speed too low

Check fan for blockage.
Check the gas type and flue system setting in the commissioning assistant and correct if necessary. Reset the boiler.

F.72

Burner in a fault state

Fan idle state not reached

Reset the boiler.
If fault occurs repeatedly, replace fan unit.

F.74

Burner locked out.
Internal circulation pump off. No central heating and no DHW heating.

System pressure too low

Top up with water. Vent the system.
If the fault occurs repeatedly:
Check system pressure sensor with external pressure gauge.
Check diaphragm expansion tank pre-charge pressure.
Check settings for target system pressure and range.

Troubleshooting

Vitocrossal 200 CI2 Service

Fault Messages (continued)

Displayed fault code

System characteristics

Cause

Measures

F.77

Burner in a fault state

Data memory burner control unit

Reset the boiler.
If the fault recurs, replace the BCU burner control unit.

F.87

Burner in a fault state

Water pressure too high

Replace the water pressure sensor.
Replace the safety assembly. Open BDF valves.
Check expansion vessel function.
Correct the amount of water in the system.

F.89

No central heating and no DHW heating

Circulation pump blocked

Check circulation pump. Replace if necessary.

F.91

Function of affected extension in emergency mode

DIO electronics module communication error

Check connections to DIO electronics module and connection to heat management unit.

F.92

Function of the relevant electronics module in emergency mode

ADIO electronics module communication error

Check setting in the commissioning assistant and correct if necessary.
Check connections and leads to the ADIO electronics module.
Check PlusBus voltage level (24 to 28V).
Check subscriber number on rotary switch S1 and correct if necessary.

F.94

Function of the relevant electronics module in emergency mode

Check setting in the commissioning assistant and correct if necessary.
Check connections and leads to the SDIO electronics module.
Check PlusBus voltage level (24-28V).

F.99

Electronics modules connected to PlusBus not functioning

Communication error PlusBus

Check setting in the commissioning assistant and correct if necessary.
Check the connecting elements (plugs) for firm seating and corrosion.
Check for connection of an incorrect device; refer to the connection diagram/installation instructions.
After checking, reset the power supply to the system and check whether the fault recurs.
If the fault recurs after the burner control unit has been restarted, replace the burner control unit concerned.

F.100

Electronics modules connected to PlusBus not functioning

Voltage error PlusBus

Check whether the PlusBus power supply on the HMU heat management unit is OK: Remove all connected PlusBus components and reconnect one by one.
Check that there aren’t more than 2 Vitotrol 200-E connected to the HMU.
Check whether there is a short circuit at the PlusBus cable.
Check the PlusBus voltage.

Vitocrossal 200 CI2 Service

Troubleshooting

Fault Messages (continued)

Displayed fault code

System characteristics

Cause

Measures

F.104

Depending on configuration of EM-EA1 extension
(DIO electronics module)

External fault message input active

Check connected external device.

F.142

Burner in a fault state

Communication error CAN bus

Check the fan unit for correct function. For this, check the stepper motor of the fan unit (reference run with mains ON).
If the fault still persists, visually check the plug-in connections and cables of the CAN bus.
Check further CAN bus subscribers. If fault still persists, replace the fan unit.

F.160

Burner in a fault state

Communication error CAN bus

If “Connection error” is displayed, check the internal CAN bus subscriber connections.
If only F.160 is displayed, check the connections of the external CAN bus subscribers.
Check the connecting cables for firm seating and corrosion. Reset the boiler.

F.180

Burner in a fault state

Gas pressure too low

Check gas pressure. Notify the gas supply utility if necessary.
Check whether the gas pressure switch is working properly. Replace the gas fitting if necessary
Direct replacement of the gas pressure switch is not permissible.

F.182

No DHW heating

Short circuit, outlet temperature sensor (if installed)

Check outlet temperature sensor (plug X1, cores 13 and 14).
Measure sensor input on electronics module. Target value: 3.3V– with sensor disconnected

F.183

No DHW heating

Lead break, outlet temperature sensor (if installed)

Check the outlet temperature sensor.

F.185

Burner in a fault state

Lead break, supply temperature sensor/high limit safety cut-out

Check the supply temperature sensor/ high limit safety cut-out. Check sensor lead. Replace faulty component if necessary. Reset the boiler.

F.299

Time/date incorrect

Real time clock setting incorrect

Set the time and date.

F.342

No central heating, no DHW heating

Communication error, BCU burner control unit

Check connecting cable to the burner control unit plug X4 on BCU.
Check all plug-in connections and cables of the internal CAN. Remove all plugs except X4,
X2, X16 and X18 from the BCU burner control unit.
Check whether fault persists. Note: Several other fault messages will be added due to the removed plugs. Ignore these. If fault message
F.342 is no longer shown, reinsert the plugs one by one and establish which component is faulty.
Reset the boiler.

Troubleshooting

Vitocrossal 200 CI2 Service

Fault Messages (continued)

Displayed fault code

System characteristics

Cause

Measures

F.343

Regulates without return temperature
sensor for low loss header

Short circuit of the common return sensor

Check the low loss header setting in the commissioning assistant and correct if necessary.
Check return temperature sensor for low loss header. Measure sensor input on electronics module.
(3.3V– with sensor disconnected)

F.344

Regulates without return temperature
sensor for low loss header

Lead break of the common return sensor

Check return temperature sensor for low loss header. Measure sensor input on electronics module.
(3.3V– with sensor disconnected)

F.348

Burner in a fault state

Gas modulation valve

If several boilers are connected to a common flue system: Check whether “Multiple connections” is set in the commissioning assistant.
Check the flue system for unrestricted flow.
If the fault persists, replace the gas fan unit.

F.353

Burner shutdown with restart if demand exists

Insufficient gas supply, burner output reduced

Check the gas supply.
Optically check input-side screen in the gas solenoid valve for contamination.
Reset the boiler.

F.354

Burner in a fault state

Gas modulation valve tolerance outside permissible range

Replace gas fan unit.

F.365

Burner in a fault state

Gas fitting relay monitoring has responded

Start the burner several times; replace the burner control unit if necessary.

F.370

Burner in a fault state

Fuel valve or modulation valve will not close.

Reset the boiler.
If fault occurs repeatedly, replace fan unit.

F.379

Burner in a fault state

Flame signal not present or insufficient

Check ionization electrode connecting cable for damage and firm seating.
Check ionization electrode; replace if necessary.
Reset the boiler.

F.380

Burner in a fault state

Flame loss immediately after flame formation (during safety time)

Check gas supply (gas pressure). Check balanced flue system for flue gas recirculation.
Check ionization electrode and burner gauze assembly:
Clearance to burner gauze assembly
Contamination on electrode Reset the boiler.

Vitocrossal 200 CI2 Service

Troubleshooting

Fault Messages (continued)

Displayed fault code

System characteristics

Cause

Measures

F.415

System in a fault state

Communication error of M bus gateway

Check the control cable and power supply.

F.416

Burner locked out

Flue gas temperature sensor incorrectly positioned

Fit flue gas temperature sensor correctly. See “Repairs”.
Carry out mains reset after fault has been remedied.

F.425

System operating normally; calculation not working

Time synchronization failed

Set the time. If external time is used, check parameters 1504 and 508.

F.430

Normal operation in line with target values of boiler

Communication error gateway

Check gateway module connecting cable and power supply.

F.517

Normal operation, remote con- trol unit not functioning

Lead break, PlusBus cable, incorrect boiler address set, remote control faulty

Check setting in commissioning assistant.
Check remote control cable.
Check remote control subscriber number. Replace faulty remote control if applicable.

F.519

Communication with the building management system is not possible. External control is not possible.
The boiler returns to the internal control target values.

Communication error BACnet. Same device ID twice in the same network.

Check the connecting cable and power supply to the WAGO gateway.
Check the BACnet participants.

F.520

Communication with the building management system is not possible. External control is not possible.
The boiler returns to the internal control target values.

Communication error Modbus. 2 identical device IDs in the same network

Check the connecting cable and power supply to the WAGO gateway.
Check the Modbus participants.

F.527

Burner in a fault state

Incorrect parameter set, HMU heat management unit

Overwrite (flash) the HMU heat management unit with the correct parameter set.

F.528

Burner in a fault state

Incorrect parameter set, BCU burner control unit

Overwrite (flash) the BCU burner control unit with the correct parameter set.

F.542

Emergency function operating mode is activated for heating circuit 1: Heating circuit pump is switched on
Heating circuit mixing valve is moved to the CLOSED position

Lead break, supply temperature sensor, heating circuit 1, incorrect setting during commissioning

Check supply temperature sensor, mixing valve 1.
Measure sensor input on electronics module. (3.3V– with sensor disconnected) Check commissioning assistant setting.
Check setting of ADIO rotary switch

F.543

Emergency function operating mode is activated for heating circuit 1: Heating circuit pump is switched on.
Heating circuit mixing valve is moved to the CLOSED position.

Short circuit, supply temperature sensor, heating circuit 1

Check supply temperature sensor, mixing valve 1.
Measure sensor input on electronics module. (3.3V– with sensor disconnected)

Troubleshooting

Vitocrossal 200 CI2 Service

Fault Messages (continued)

Displayed fault code

System characteristics

Cause

Measures

F.544

Mixing valve closes. Heating circuit pump is operational.

Lead break, supply temperature sensor, heating circuit 2 with mixing valve
Incorrect setting during commissioning

Check supply temperature sensor, mixing valve 2.
Measure voltage at sensor input on electronics module.
Target value: 3.3V– with sensor disconnected.
Check commissioning assistant setting.
Checking setting of ADIO rotary switch.

F.545

Mixing valve closes. Heating circuit pump is operational.

Short circuit, supply temperature sensor for heating circuit 2 with mixing valve

Check supply temperature sensor, mixing valve 2.
Measure voltage at sensor input on electronics module.
Target value:
3.3V– with sensor disconnected

F.546

Mixing valve closes. Heating circuit pump is operational.

Lead break, supply temperature sensor, heating circuit 3 with mixing valve

Check supply temperature sensor, mixing valve 3.
Measure voltage at sensor input on electronics module.
Target value:
3.3V– with sensor disconnected. Check commissioning assistant setting. Checking setting of ADIO rotary switch.

F.547

Mixing valve closes. Heating circuit pump is operational.

Short circuit, supply temperature sensor for heating circuit 3 with mixing valve

Check supply temperature sensor, mixing valve 3.
Measure voltage at sensor input on electronics module.
Target value:
3.3V– with sensor disconnected

F.548

Mixing valve closes. Heating circuit pump is operational.

Short circuit, supply temperature sensor for heating circuit 4 with mixing valve

Check supply temperature sensor, mixing valve 4.
Measure voltage at sensor input on electronics module. Target value:
3.3V– with sensor disconnected
Check commissioning assistant setting.
Checking setting of ADIO rotary switch.

F.549

Mixing valve closes. Heating circuit pump is operational.

Short circuit, supply temperature sensor for heating circuit 4 with mixing valve

Check supply temperature sensor, mixing valve 4.
Measure voltage at sensor input on electronics module.
Target value:
3.3V– with sensor disconnected

F.574

Room temperature sensor for heating circuit 1 not available.

Normal operation without room influence

Check external room temperature sensor for heating circuit or room temperature sensor with remote control unit.

F.575

Normal operation without room influence

Lead break, room temperature sensor, heating circuit 1

Check external room temperature sensor for heating circuit or room temperature sensor with remote control unit

F.576

Normal operation without room influence

Short circuit, room temperature sensor, heating circuit 1

Check external room temperature sensor for heating circuit or room temperature sensor with remote control unit

Vitocrossal 200 CI2 Service

Troubleshooting

Fault Messages (continued)

Displayed fault code

System characteristics

Cause

Measures

F.577

Normal operation without room influence

Room temperature sensor for heating circuit 2 not available

Check external room temperature sensor for heating circuit or room temperature sensor with remote control unit
Check setting of parameter 934.6.

F.578

Normal operation without room influence

Lead break, room temperature sensor, heating circuit 2

Check external room temperature sensor for heating circuit or room temperature sensor with remote control unit.

F.579

Normal operation without room influence

Short circuit, room temperature sensor, heating circuit 2

Check external room temperature sensor for heating circuit or room temperature sensor with remote control unit.

F.580

Normal operation without room influence

Room temperature sensor for heating circuit 3 not available

Check external room temperature sensor for heating circuit or room temperature sensor with remote control unit.
Check setting of parameter 935.6.

F.581

Normal operation without room influence

Lead break, room temperature sensor, heating circuit 3

Check external room temperature sensor for heating circuit or room temperature sensor with remote control unit.

F.582

Normal operation without room influence

Short circuit, room temperature sensor, heating
circuit 3

Check external room temperature sensor for heating circuit or room temperature sensor with remote control unit.

F.583

Normal operation without room influence

Room temperature sensor for heating circuit 4 not available

Check external room temperature sensor for heating circuit or room temperature sensor with remote control unit.

F.584

Normal operation without room influence

Lead break, room temperature sensor, heating circuit 4

Check external room temperature sensor for heating circuit or room temperature sensor with remote control unit.

F.585

Normal operation without room influence

Short circuit, room temperature sensor, heating circuit 4

Check external room temperature sensor for heating circuit or room temperature sensor with remote control unit.

F.623

Emergency function operating mode is activated for
heating circuit 1: Heating circuit pump is switched on.
Heating circuit mixing valve is moved to CLOSED position

Lead break, return temperature sensor, heating circuit

Check return temperature sensor, mixing valve 1.
Measure sensor input on electronics module. (3.3V DC with sensor disconnected)

F.624

Emergency function operating mode is activated for
heating circuit 1: Heating circuit pump is switched on.
Heating circuit mixing valve is moved to CLOSED position

Short circuit, return temperature sensor, heating circuit 1

Check return temperature sensor, mixing valve 1.
Measure sensor input on electronics module. (3.3V DC with sensor disconnected)

Troubleshooting

Vitocrossal 200 CI2 Service

Fault Messages (continued)

Displayed fault code

System characteristics

Cause

Measures

F.625

Emergency function operating mode is activated for heating circuit 2: Heating circuit pump is switched on.
Heating circuit mixing valve is moved to CLOSED position

Lead break, return temperature sensor, heating circuit 2

Check return temperature sensor, mixing valve 2.
Measure sensor input on electronics module. (3.3V DC with sensor disconnected)

F.626

Emergency function operating mode is activated for heating circuit 2: Heating circuit pump is switched on.
Heating circuit mixing valve is moved to CLOSED position

Short circuit, return temperature sensor, heating circuit 2

Check return temperature sensor, mixing valve 2.
Measure sensor input on electronics module. (3.3V DC with sensor disconnected)

F.627

Emergency function operating mode is activated for heating circuit 3: Heating circuit pump is switched on.
Heating circuit mixing valve is moved to CLOSED position

Lead break, return temperature sensor, heating circuit 3

Check return temperature sensor, mixing valve 3.
Measure sensor input on electronics module. (3.3V DC with sensor disconnected)

F.628

Emergency function operating mode is activated for heating circuit 3: Heating circuit pump is switched on.
Heating circuit mixing valve is moved to CLOSED position

Short circuit, return temperature sensor, heating circuit 3

Check return temperature sensor, mixing valve 3.
Measure sensor input on electronics module. (3.3V DC with sensor disconnected)

F.629

Emergency function operating mode is activated for heating circuit 4: Heating circuit pump is switched on.
Heating circuit mixing valve is moved to CLOSED position

Lead break, return temperature sensor, heating circuit 4

Check return temperature sensor, mixing valve 4.
Measure sensor input on electronics module. (3.3V DC with sensor disconnected)

F.630

Emergency function operating mode is activated for heating circuit 4: Heating circuit pump is switched on.
Heating circuit mixing valve is moved to CLOSED position

Short circuit, return temperature sensor, heating circuit 4

Check return temperature sensor, mixing valve 4.
Measure sensor input on electronics module. (3.3V DC with sensor disconnected)

F.688

Function of the relevant electronics module in emergency mode

Communication error MZIO

Check setting in the commissioning assistant and correct if necessary.
Check connections and leads
to the MZIO electronics module.
Check PlusBus voltage level (24 to 28V).

F.691

System in a fault state

No feedback, ventilation air supply preventing burner start

Check plug connection, check for blockages of the ventilation air damper, replace if necessary.

F.692

System in a fault state

Burner ventilation air supply interrupted

Check plug connection, check for blockages of the ventilation air damper, replace if necessary.

Vitocrossal 200 CI2 Service

Troubleshooting

Fault Messages (continued)

Displayed fault code

System characteristics

Cause

Measures

F.762

System in a fault state

System pressure too low

Top up with water. Vent the system. If the fault recurs:
Check the minimum pressure switch with an external pressure gauge.
Check diaphragm expansion tank pre-charge pressure.
Check safety chain plugs on burner control unit.

F.764

System in a fault state

Lag boiler reports a fault

Check the lag boiler fault.

F.765

System in a fault state

Communication error lag boiler

Check communication of lag boiler.

F.875

System in a fault state

Communication error lead boiler

Check communication of lead boiler.

F.882

Burner/system in a fault state

Gas outlet pressure too high (GDW3)

Check gas pressure switch 3 and the gas outlet pressure (GDW3). If necessary, replace the pre- assembled gas line (399/500 MBtu) or gas fitting (750/1000 MBtu).

F.883

Burner/system in a fault state

Gas valve test malfunction: Electronic fault with gas fitting or CAN bus communication error

Restart the burner several times. If necessary, replace the burner control unit or E-Box.

F.884

Burner/system in a fault state

Gas valve test malfunction: VPS pressure (GDW 2) does not increase during filling

Check gas inlet pressure. Restart the burner several times. If necessary, replace the burner control unit or E-Box.

F.885

Burner/system in a fault state

Gas valve test faulty, valve seat V2 faulty

Replace the gas fitting.

F.886

System in a fault state

Gas valve test malfunction: VPS pressure (GDW 2) does not drop during VPS test.

Restart the burner several times. If necessary, replace the burner control unit or E-Box.

F.887

System in a fault state

Gas valve test faulty, valve seat V1 faulty

Replace the gas fitting.

F.888

System in a fault state

Communication error with Lambda probe controller (burner control unit internal error)

Replace burner control unit.

F.889

System in a fault state

Lambda probe malfunction: Cyclic probe check failed

Check Lambda probe plug and replace if necessary.

F.890

System in a fault state

Lambda probe malfunction: Cyclic probe check failed

Check Lambda probe plug and replace if necessary.

F.891

System in a fault state

Lambda probe malfunction: Probe not ready for operation in pre/postpurge

Check ventilation air/flue system and condensate drain; clean if necessary.
Check Lambda probe plug and replace if necessary.

Troubleshooting

Vitocrossal 200 CI2 Service

Fault Messages (continued)

Displayed fault code

System characteristics

Cause

Measures

F.892

Burner in a fault state

Lambda probe malfunction: Calibration failed

Check ventilation air/flue system and condensate drain; clean if necessary.
Check flue gas recirculation. Check Lambda probe plug and replace if necessary.

F.893

Burner in a fault state

Lambda probe malfunction: Calibration failed

Check ventilation air/flue system and condensate drain; clean if necessary.
Check flue gas recirculation. Check Lambda probe plug and replace if necessary.

F.894

Burner in a fault state

Lambda probe malfunction: Probe heating

Check Lambda probe plug and replace if necessary.
Replace burner control unit.

F.895

Burner in a fault state

Lambda probe malfunction: Wear

Check Lambda probe plug and replace if necessary.

F.896

System in a fault state

Safety chain 1 has responded

Check the hydraulic minimum pressure switch.

F.897

System in a fault state

Safety chain 2 has responded

Check low water indicator.

F.920

System in a fault state

MZIO function fault, digital input 1

Check external setup.

F.921

System in a fault state

MZIO function fault, digital input 2

Check external setup.

F.922

System in a fault state

MZIO function fault, digital input 3

Check external setup.

F.971

Burner in a fault state

When the gas fitting was replaced, the calibration value was not entered.

Replace the CV2 calibration value (see label on gas fitting) in ViGuide/ Spare parts replacement/Gas fitting.

F.982

No heating, no DHW heating

Circulation pump heating circuit 1 running dry

Check diaphragm expansion tank, check pump.

F.986

System in a fault state

Parameter plausibility check between burner 1 and burner 2 failed

Restart the boiler.

F.1001

Burner in a fault state

Burner control unit not calibrated

Replace burner control unit

F.1002

Burner in a fault state

Burner control unit not calibrated

Replace burner control unit

F.1004

System in a fault state

Reverse flow of flue gas in “dry mode” (partial load range with CI2 1500/2000 MBtu/h)

Check flue system CI2 1500/2000 / burner fan in “dry mode”; replace if necessary.
Check flue gas damper and connection.

Vitocrossal 200 CI2 Service

Troubleshooting

Burner Faults Without a Specific Message

Fault

Cause of Fault

Measures

Combustion faults due to pulsation

Excessive gas throughput

Adjust gas throughput in accordance with the rated boiler heating output.

Insufficient or excessive air

Condensate drain in the flue system blocked

Check condensate drain.

Flue outlet not installed correctly

Check flue outlet and flue system.

Burner output fluctuating

Insufficient or excessive air

Correct the settings.
Check combustion in installation room.

Insufficient draught in flue system

Check flue system.

Flame tears off during operation

Inlet strainer of gas solenoid valve contaminated

Remove flange and clean strainer.

Warning Messages

Display

Warning

Cause

Measure

A.48

Reduced system output

Condensate backup Wind influence due to
non-approved flue systems and wall terminals

Check system for condensate backup. Assemble the flue system and wall outlet according to the versions in the service instructions

Service Messages

Display

Message

Measure

P.1

Maintenance due according to interval

Carry out system maintenance

P.36

Air filter contaminated

Clean the air filter

Fault Memory
The 10 most recent faults are saved and can be called up. The most recent fault code is shown first, followed by the preceding codes.
Note: If the burner repeatedly starts up due to a non-lockout fault without displaying a fault code, the fault memory may give an indication of the cause.