I have just perform a radiator bleeding following youtube video but the pressure dropped to zero in my boiling system vaillant ecotec pro, have a permanent red light in addition to the normal green, displaying an error F22 and now I have no heating and no hot water. However I have checked additional youtube instruction to fix the error I found many but I can´t have the water running to fill the boiler, seen that there is no water running from the pipe loop. Can anyone help please? Thanks.
This is how I found the solution: on vaillant eco pro filling loop pipe there is only one visible valve with a proper handle located on the left side. Follow this pipe and where it connects on the right side instead of a normal valve with a handle there is a kind of hidden screw on top of it. Turn it anti clockwise with a screwdriver to have the water running, then you can open the valve with handle on the left to top up your boiling pressure. Be careful only topup to 1.5 bars, about half of the grey area and please Don't forget to turn back all the open valves at the end to its initial position.
Hope this helps, because it took me hours to locate this hidden valve in the right side.