I have three bedroom we adding the basement soon. I have one 15 amp breaker service running two lights & sump pump & one outlet. I also have another 15 amp breaker running two light and two outlets. And I have a third 20 amp breaker service running a fridge and a small deep freezer. Now in each room I want a ceiling fan and three outlets one of the out I need an electric heater set aside for which I know they draw quit a bit of juice. So my question is do I need to add a service line to do all of this to the rooms or can I use the three that are there? If I can use these three line how is the best why to divide it up on each breaker.

Is that one heater for each of the three rooms?
What size heaters are they?
You will almost certainly have to run at least one new circuit because of the heaters.

The existing 15 amp circuits can probably be used for the lighting and non-heater receptacles. Can you look on the nameplate of the pump motor and tell us how many amps it draws? Probably not enough to make a difference, but since it is a known load it can't hurt to have the info.