Vaillant ecotec plus 837 will not pressurise

[Tarki]

Help needed. Boiler reading 0.7 bar F75 fault code. Filling loop taps open and nothing happens no change in pressure. Had each end of the filling loop off and water flows with good pressure. Any ideas ?

 

[Deleted member 267285]

F75 - you will need 1 of 2 parts replacing or both. If water isn’t flowing into the system it could be a failed valve, as you’ll likely have a double check valve fitted

 

[Tarki]

F75 - you will need 1 of 2 parts replacing or both. If water isn’t flowing into the system it could be a failed valve, as you’ll likely have a double check valve fitted

Plumber coming back tomorrow - tried a pressure switch today didn’t work. Since then I tested the filling loop and found no blockage so as you say it appear to be a blockage between the valve and pressure switch