Glow worm/ valliant he

[Andrew thomas]

30cxi combi. Fires up every time on ch demand. Hot water demand fails. Burner lights but doesn't sence flame and locks out. Fault code f1. Have adjusted gas pressure but no change. I feel mixture is all wrong on full power but fga and gas rate is fine. Maybe fan speed all out? On this boiler what regulates fan? Which pcb? Help please anyone?????
[automerge]1579015624[/automerge]

30cxi combi. Fires up every time on ch demand. Hot water demand fails. Burner lights but doesn't sence flame and locks out. Fault code f1. Have adjusted gas pressure but no change. I feel mixture is all wrong on full power but fga and gas rate is fine. Maybe fan speed all out? On this boiler what regulates fan? Which pcb? Help please anyone????? Also does eventually fire up if heat exchanger is already warm