ideal classic nf280?

I have an Ideal ff380 boiler. The heating is not coming on with the timer?

My ideal isar HE 24 is showing F L on the screen and won't fire up. ?

My shower and hot water taps are running cold?

diveter or not?

safety relief valve?

converting to sealed system?

No heating or hot water and no idea whats wrong !!?

Gas Jet Lights but goes off again after about a minute?

knocking sound?

h3 code ideal izar he24 what is it?

rattling nosie in the ideal bolier??

where is the overheat button on an ideal elan2!!!!!?