Buderus
Fault Codes

Listed below are the common Buderus fault codes as described by the boiler manufacturer along with a possible cause.

 

 

Buderus Fault Codes

 

 

Display code

Fault

Action

No communication between UBA 3 and BC10. Press the “Reset” button, if fault persist contact your installer

0 Y 276

 

0 Y 277

 

0 Y 285

 


No communication between UBA 3 and BC10.

 

The

supply sensor has measured a temperature higher than 203 °F (95 °C)

The safety sensor has measured a temperature higher than 203 °F (95 °C)

 

Open the servicing cocks. Fill and bleed the heating system. Open a thermostatic valve. Replace the supply, safety and/or return sensors. Replace the primary circulation pump

1 L 211

The UBA 3 does not register any connections to the unused contacts 78 and 50.

Restore the contact between the UBA 3 and the UBA 3 mounting base

2 E 207

The system pressure is too low. Fill and bleed the heating system

2 F 260

2 F 277

No temperature increase after burner start or the temperature difference between the supply and safety sensors is more than 27 °F (15 K)
The temperature difference between the supply and safety sensors is more than 27 °F (15 K)
Open the servicing cocks. Fill and bleed the heating system. Open a thermostatic valve. Replace the supply and/or safety sensors. Replace the primary
circulation pump

2 L 266

The primary circulation pump does not generate a pressure difference Try to undo the jam or replace the primary circulation pump. Replace the primary circulation pump. Replace the supply cord. Clean the circulation pump (inside). Connect the expansion tank to the return conduit. Clean the pressure sensor.

2 P 212

Temperature increase of supply sensor or safety sensor is more than 7.5 °F/sec (5 K/sec) Open the servicing cocks. Fill and bleed the heating system. Open a thermostatic valve. Replace the supply and/or safety sensors. Replace the primary circulation pump

2 U 213

The temperature difference between the supply and return sensors is more than 90 °F (50 K) Open the servicing cocks. Open a thermostatic valve. Replace the supply and/or safety sensors. Replace the primary circulation pump

3 A 264

The air fan has failed during the operating phase. Reconnect the plug-and-socket connection of the blower. Replace the tacho wire. Have the electrical system tested. Replace the supply cord.

3 F 273

The blower is switched off during the safety test Fully switch off the heat request and check that the blower is still operational after 1 minute. Replace if necessary

3 L 214

The blower is switched off during the safety test Reconnect the plug-and-socket connection of the blower. Replace the tacho wire. Have the electrical system tested. Replace the supply cord.

3 P 216

The blower is running too slowly Clean or replace the blower. Have the electrical system tested.

3 Y 215

The blower is running too fast Restore the plug-and-socket connection. Replace the tacho wire. Have the electrical system tested. Deal with blockage. Take the second blower out of service. Replace the blower

4A 218

C A 286

The supply sensor has measured a temperature higher than 221 °F (105 °C)
The return sensor has measured a temperature higher than 221 °F (105 °C)
Open the servicing cocks. Fill and bleed the heating system. Open a thermostatic valve. Replace the primary circulation pump. Replace the supply and return sensor

4C 224

The UBA 3 does not register the short cut between the unused contacts 22 and 24 Restore the contact between the UBA 3 and the UBA 3 mounting base.

4E 278

The sensor test has failed Replace the cable loom or the affected part thereof

4L 220

The safety sensor is shorted or measures temperatures higher than 266 °F (130 °C) Open the servicing cocks. Fill and bleed the heating system. Open a thermostatic valve. Replace the primary circulation pump. Replace the cable loom or the affected part thereof. Replace the safety sensor

4P 227

The safety sensor contact is interrupted Replace the cable loom or the affected part thereof. Replace the safety sensor

4U 222

C U 240

The supply sensor contact is shorted
The return sensor contact is shorted
Replace the cable loom or the affected part thereof. Replace the supply and return sensor

4 Y 223

C Y 241

The supply sensor contact is interrupted
The return sensor contact is interrupted
Replace the cable loom or the affected part thereof. Replace the supply and return sensor

6 A 227

No ionization after four startup attempts Contact the gas utility company to ensure that no nitrogen remains in the gas tank or gas supply pipes. Bleed the gas supply pipe. Replace the hot surface ignitor. Adjust the gas/air ratio. Fit the correct gas orifice. Clean and/or replace the corresponding components. Deal with blockage.

6 C 228

An ionization current was measured before the burner start. Replace the ionization electrode

6 C 306

An ionization current was measured after the burner switch-off Replace the gas valve

6 L 229

Ionization fails during the operating phase Ensure that no nitrogen remains in the gas tank or gas supply pipes, in close consultation with the gas utility company. Bleed the gas supply pipe. Adjust the gas/air ratio. Clean and/or replace the corresponding components

6 P 269

The hot surface ignitor activates too long KIM defective, contact the Buderus customer service

7 C 231

The power supply was interrupted after a fault message Press the “Reset” button, if fault persist contact your installer

7 L 261

7 L 280

The UBA 3 is defective
The UBA 3 is defective
Contact the Buderus customer service or your installer

8 Y 232

The external switch contact is activated External switch contact has energized. Replace the cable loom or the affected part thereof. Restore the contact. Restore the bridge on the terminal strip again

9 A 235

9H 237

9 P 239

9 U 233

E 242-287

E 290

KIM or UBA 3 is defective
KIM or UBA 3 is defective
KIM or UBA 3 is defective
KIM or UBA 3 is defective
KIM or UBA 3 is defective
The UBA 3 is defective.
Contact the Buderus customer service or your installer

9 L 234

9 L 238

The gas valve coil or the wiring to the gas valve is defective
The UBA 3 is defective
Restore the plug-and-socket connection. Replace the cable loom or the affected part thereof. Replace the gas valve

C 0 288

C 0 289

The UBA 3 has no connection to the pressure sensor or there is a short circuit
Short circuit in connection to pressure sensor
Restore the plug-and-socket connection. Replace the cable loom or the affected part thereof. Replace the UBA 3

Attention! Buderus boilers require a correct fuel to ensure a proper operation. Especially because the statistics show that Buderus boiler faults occur mostly due to two reasons

  • wrong installation and commissioning
  • wrong or dirty fuel

Remedying burner faults

As mentioned above there are two types of faults burner faults and the control device and heating system faults. Whenever there is a burner fault, the lamp located on the burner will flash. In most cases those faults can be remedied by simply resetting the burner/ resetting the appliance (look below procedure on how to reset the boiler). Heating system faults/errors will be displayed on the display of the control device. Control device and heating system fault finding is included in the section above. To remedy burner faults you should remove the burner hood, if the boiler has an integral burner. Next you should press the burner reset button as shown on the picture below

 

 

ok

 

 

 

 

 

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