I believe I have c series combi system with only one dial every time I turn the dial the green light comes on followed by the orange light then a clicking noise followed by the red light and the orange light starts to fade and go out the gas is working and full up as is the water can any one help please as buying another boiler is outta the question ( no funds left) all I get from truma is this one is obsulit you got a fault it needs to be seen buy an engineer I'm not gonna lie in not technically minded thanks