[wayne robson]

Hi Doug when you lost coolant at the first, then added more at home or later,
what can happen ,the system then requires primed or and vented,
you should run from cold with heater on hot side, while warming up
add coolant, this opens up the heater valves, at get rid of any air in
the system, also on your car i think there is a vent or similiar item near top or
inside radiator cap, open this when it is nearly hot, then top up as required
This should fix your problem.---- except for worn belts,hoses,old coolant , etc.
regards