Ferroli Modena 80E Heating problem ?

I have a Ferroli Modena 80E in my flat, about two weeks ago the heating stopped working. The hot water is still working but nothing we do seems to turn the heating on. We have spoken to our landlord she has advised us to reset buy turning the on/off switch past the off side for three seconds which to reset the boiler. When we do this the heater symbol flashes for a few minutes then stops without the heating ever turning on. We have also looked through the very confusing manual but we are a household of two young women and aren't boiler technicians!
The problem lies here - we are now approaching winter and our flat is freezing, our landlord says that if there isnt anything wrong with the boiler and we have just adjusted a setting (which we haven't) she will pass the cost of a boiler engineer onto us. Her point is that the boiler is still heating the water so isn't broken, so must just be a setting problem.

Does anyone know what the problem could be?