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boiler service, boiler repair, emergency repair
Vaillant ecoTEC plus 48 Boiler Fault Codes
| Message | Possible Cause | Measure |
|
F00 Flow temperature sensor interruption |
NTC plug loose/not plugged in NTC sensor defective Multiple plug loose/not plugged in Interruption in the cable harness |
▶ Check the NTC plug and plug connection. ▶ Replace the NTC sensor. ▶ Check the multiple plug and plug connection. ▶ Check the cable harness |
|
F01 Return temperature sensor interruption |
NTC plug loose/not plugged in NTC sensor defective Multiple plug loose/not plugged in Interruption in the cable harness |
▶ Check the NTC plug and plug connection. ▶ Replace the NTC sensor. ▶ Check the multiple plug and plug connection. ▶ Check the cable harness |
|
F03 Cylinder temperature sensor interruption |
NTC sensor defective NTC plug loose/not plugged in Connection to cylinder electronics defective |
▶ Replace the NTC sensor. ▶ Check the NTC plug and plug connection. ▶ Check the connection to the cylinder electronics. |
|
F10 Flow temperature sensor short circuit |
NTC sensor defective Short circuit in the cable harness |
▶ Replace the NTC sensor. ▶ Check the cable harness. |
|
F11 Return temperature sensor short circuit |
NTC sensor defective Short circuit in the cable harness |
▶ Replace the NTC sensor. ▶ Check the cable harness. |
|
F13 Cylinder temperature sensor short circuit |
NTC sensor defective Short circuit in the cable harness |
▶ Replace the NTC sensor. ▶ Check the cable harness. |
|
F20 Safety shutdown: Safety cut-out |
Flow NTC defective Return NTC defective Earth connection faulty Stray spark via the ignition cable, ignition plug or ignition electrode |
▶ Check the flow NTC. ▶ Check the return NTC. ▶ Check the earth connection. ▶ Check the ignition cable, ignition plug and ignition electrode. |
|
F22 Safety shutdown: Water deficiency |
Insufficient/no water in the product. Interruption in the cable harness
|
▶ Fill the heating installation. (→ Page 23) ▶ Check the cable harness. |
|
F23 Safety shutdown: Temperature spread too great |
Pump blocked Pump runs with insufficient output Flow and return NTC connected the wrong way round |
▶ Check that the pump is working correctly. ▶ Check that the pump is working correctly ▶ Check the connection for the flow and return NTC. |
|
F24 Safety shutdown: Temperature rise too fast |
Pump blocked Pump runs with insufficient output Non-return valve blocked Non-return valve installed incorrectly System pressure too low |
▶ Check that the pump is working correctly. ▶ Check that the pump is working correctly. ▶ Check that the non-return valve is working correctly. ▶ Check the installation position of the non-return valve. ▶ Check the system pressure. |
|
F25 Safety shutdown: Flue gas temperature too high |
Flue gas safety cut-out plug is not plugged in or is loose Interruption in the cable harness |
▶ Check the plug and the plug connection. ▶ Check the cable harness. |
|
F27 Safety shutdown: Flame simulation |
Gas solenoid valve not leak-tight Moisture on the PCB Flame monitor defective |
▶ Check that the gas solenoid valve works correctly. ▶ Check that the PCB works correctly ▶ Replace the flame monitor. |
|
F28 Ignition unsuccessful |
Gas stopcock closed Gas valve assembly defective The gas pressure monitor has been triggered Gas flow pressure too low The thermal isolator device has been triggered Cable connections not plugged in/loose Ignition system defective PCB defective Ionisation flow interrupted Earthing defective Air in the gas supply Gas meter defective Gas supply is interrupted Flue gas circulation is incorrect Ignition misfire Diagnostics code D.085 incorrectly set
Condensate siphon blocked |
▶ Open the gas stopcock. ▶ Replace the gas valve assembly. ▶ Check the gas flow pressure. ▶ Check the gas flow pressure. ▶ Check the thermal isolator device. ▶ Check the cable connections. ▶ Replace the ignition system. ▶ Replace the PCB. ▶ Check the monitoring electrodes ▶ Check the product's earthing. ▶ Check the gas-air ratio. ▶ Replace the gas meter. ▶ Check the gas supply. ▶ Check the air/flue system. ▶ Check that the ignition transformer works correctly. ▶ Using an installation with a flue non-return flap, check whether the diagnostics code D.085 has been set correctly. (→ Page 19) 1. Check whether the condensate discharge is connected correctly. (→ Page 18) 2. If the drain is blocked, check whether the heat exchanger's internal insulating material is OK. |
|
F29 Ignition and check faults during operation – flame has gone out |
Gas valve assembly defective Gas meter defective The gas pressure monitor has been triggered Air in the gas supply Gas flow pressure too low The thermal isolator device has been triggered Cable connections not plugged in/loose Ignition system defective Ionisation flow interrupted Earthing defective PCB defective |
▶ Replace the gas valve assembly. ▶ Replace the gas meter. ▶ Check the gas flow pressure. ▶ Check the gas-air ratio. ▶ Check the gas flow pressure. ▶ Check the thermal isolator device. ▶ Check the cable connections. ▶ Replace the ignition system. ▶ Check the monitoring electrodes. ▶ Check the product's earthing. ▶ Replace the PCB. |
|
F32 Fan fault |
Plug on fan not plugged in or is loose Multiple plug loose/not plugged in Interruption in the cable harness Fan blocked Electronics defective |
▶ Check the plug on the fan and the plug connection. ▶ Check the multiple plug and plug connection. ▶ Check the cable harness. ▶ Check that the fan works correctly. ▶ Check the PCB. |
|
F33 Air pressure switch fault |
Air/flue pipe blocked Defective air pressure switch Cable connections not plugged in/loose Fan defective |
▶ Check the entire air/flue pipe ▶ Replace the air pressure switch. ▶ Check the cable connections. ▶ Check that the fan works correctly. |
|
F33 Air pressure switch fault |
PCB defective Excessive counter-pressure in the air/flue pipe |
▶ Replace the PCB. 1. Ensure that there is no risk of excessive counter-pressure. 2. If required, protect the product (wind guard, cascade lines with a larger diameter, etc.). |
|
F49 Fault: eBUS |
eBUS overload Short circuit in the eBUS connection Different polarities at the eBUS connection |
▶ Check that the eBUS connection works correctly. ▶ Check that the eBUS connection works correctly. ▶ Check that the eBUS connection works correctly. |
|
F61 Gas safety valve drive fault |
Short circuit in the cable harness Gas valve assembly defective PCB defective |
▶ Check the cable harness. ▶ Replace the gas valve assembly ▶ Replace the PCB. |
|
F62 Gas safety valve connection fault |
PCB defective The connection to the gas valve assembly has been interrupted/broken |
▶ Replace the PCB. ▶ Check the connection to the gas valve assembly |
|
F63 Fault: EEPROM |
PCB defective | ▶ Replace the PCB. |
|
F64 Fault: Electronics/NTC |
Flow NTC short circuit. Return NTC short circuit PCB defective |
▶ Check that the flow NTC works correctly. ▶ Check that the return NTC works correctly. ▶ Replace the PCB. |
|
F65 Electronics temperature fault |
Electronics overheated PCB defective
|
▶ Check the external heat effects on the electronics. ▶ Replace the PCB and the ionisation electrode. |
|
F67 Flame plausibility fault |
PCB defective | ▶ Replace the PCB. |
|
F70 Invalid device specific number (DSN) |
Device Specific Number not set/is incorrect Output range coding resistor missing or is incorrect |
▶ Set the correct Device Specific Number ▶ Check the output range coding resistor. |
|
F71 Flow temperature sensor fault |
The flow NTC reports a constant value Incorrect position of the flow NTC Flow NTC defective |
▶ Check the positioning of the flow NTC. ▶ Check the positioning of the flow NTC. ▶ Replace the flow NTC. |
|
F72 Flow and/or return temperature sensor fault |
Flow NTC defective Return NTC defective |
▶ Replace the flow NTC ▶ Replace the return NTC. |
|
F73 Water pressure sensor signal in the wrong range (too low) |
Short circuit in the cable harness Interruption in the cable harness Water pressure sensor defective |
▶ Check the cable harness. ▶ Check the cable harness. ▶ Replace the water pressure sensor. |
|
F74 Water pressure sensor signal outside correct range (too high) |
Short circuit in the cable harness Interruption in the cable harness Water pressure sensor defective |
▶ Check the cable harness. ▶ Check the cable harness. ▶ Replace the water pressure sensor. |
|
F75 Pump fault/water deficiency |
Malfunction D.149 = 1, pump blocked alarm D.149 = 2, electrical pump fault alarm D.149 = 3, pump dry running alarm D.149 = 5, no pressure peak detection D.149 = 6, no feedback from the pump D.149 = 7, incorrect pump detected D.149 = 8, flow rate at the end of the purge programme is insufficient |
▶ Call up diagnostics code D.149 to obtain further information about the malfunction. 1. Remove the blockage from the pump. 2. Replace the pump. 1. Check the pump's supply voltage. 2. Replace the pump. 1. Check the pressure of the hydraulic circuit; ensure that there is no air in the circuit. 2. Replace the pump. 1. Check the system pressure. 2. Purge the heating installation (purge programme). 3. Check the water pressure sensor. 4. Replace the water pressure sensor. 1. Check the pump's cable harness. 2. Check the main PCB. 3. Check that the plugs are connected correctly. 4. Check the pump's supply voltage. – ≥ 195 V 5. Replace the pump. 6. Replace the main PCB. 1. The detected pump is not correct for the product code; check the product code. 2. Use the pump that has the correct article number. 1. Check whether the stopcocks and thermostatic valves are open. 2. Check the filling pressure; purge the circuit. – ≥ 0.15 MPa (≥ 1.50 bar) |
|
F77 Accessory fault (flue nonreturn flap, condensate pump, etc.) |
No feedback from the flue nonreturn flap or the feedback is incorrect Flue non-return flap defective No feedback from the condensate pump or the feedback is incorrect |
▶ Check that the flue non-return flap works without any problems. ▶ Replace the flue non-return flap. ▶ Check that the condensate pump is working correctly.
|
|
F83 Fault: Flow and/or return temperature sensor temperature change |
Water deficiency Flow NTC: No contact Return NTC: No contact |
▶ Fill the heating installation. ▶ Check whether the flow NTC is lying against the flow pipe correctly. ▶ Check whether the return NTC is lying against the return pipe correctly.
|
|
F84 Fault: Temperature difference at the flow and return temperature sensors |
Flow NTC installed incorrectly Return NTC installed incorrectly |
▶ Check that the flow NTC has been installed correctly ▶ Check that the return NTC has been installed correctly. |
|
F85 Flow and return temperature sensors have been installed incorrectly (inverted) |
Flow/return NTC installed on the same/incorrect pipe | ▶ Check that the flow and return NTCs have been installed on the correct pipe. |