Vokera Flowmatic boiler error code A08

Hello Folks,

My newly bought and installed Vokera Flowmatic boiler is displaying an AO8 error code from last few days. What does it mean? I have tried to fix it but no success. What should I do rectify this annoying this problem?



Hi Brian,

This error code means your boiler is having a “temperature differential problem”. It happens when flow pipe becomes colder than a return pipe. Another common cause is that a return thermistor is out of order. Luckily, thermistors are low priced and you can replace them easily. However, firstly call a boiler engineer and ask him to test a NTC thermistor. If the thermistor is giving the right readings then, it is possibly due to the faulty PCB rather than a thermistor.