Problem with Ideal Isar HE24?

Hi All,
I wonder if anyone can help me. The problem that I am having is that the central heating does not seem to be working anymore. I do not have any error messgaes flashing on the display. I only have a "d" and a falshing burner sign. "c" does not come up (only when switching the boiler on it comes up for few seconds).
I have hot water no problem - issue seems to be affecting the central heating only. I checked the programmer and the thermostat and they seem to be working - I can change the heating modes no problem on the programmer. Theres is a normal clicking sound when changing the heating on from off but unfortunately burner does not fire up. Thermostat is set to maximum and the programmer is set to always on. Is there anyhting else I can check?

R. Harrison-Staska
January 2011