Hi.
I have a vaillant ecotec plus 630. I get the F.22 error message atleast once a month this year, which means that I have to keep topping it up with fresh water from the valve. Last year this never happen and I only got the boiler installed at the beginning of last year. I have wet underfloor heating downstairs and rads upstairs with one room having vertical designer rads which sounds as though there is a mini water fall inside it (trickling water noise). Can you help me?

Redsoldier, November 2015

The noise in the radiator would indicate it needs bleeding, unfortunately for you, it sounds as though you have a water leak somewhere on the system.
This would be consistent with 'topping up' the pressure and the gathering air in the radiator. Simply put, you have to find and repair the leak.

Carefree, December 2015