Vaillant EcoMax Pro 18/28E Boiler Error Codes

Vaillant EcoMax Pro 18/28E Boiler Error Codes

EcoMax Pro 18/28E Fault Code Possible Cause
F.1 Lack of gas, a fault with the ignition or flue, or you may need to adjust the gas valve or replace a defective electrode lead.
F.4 Ignition fault.
F.5 The system has suffered a fault due to overheating.
F.6 Your flow NTC (temperature sensor) has developed a fault.
F.17 Check the polarity of your system
F.21 The pump could have failed, over run or there could be an issue with the air lock.