Can someone help diagnose Vaillant ecoTEC plus 837 with persisting F75 fault please?
We already replaced the pressure sensor, installed F75 kit, replaced the main heat exchanger, and the pump, and the PCB, and flushed the system and installed a filter on the return, but still sometimes we get F75. The boiler still reset and run, but we would like to get to the bottom of it if at all possible. Thanks in advance.
We already replaced the pressure sensor, installed F75 kit, replaced the main heat exchanger, and the pump, and the PCB, and flushed the system and installed a filter on the return, but still sometimes we get F75. The boiler still reset and run, but we would like to get to the bottom of it if at all possible. Thanks in advance.