How do I know if my high limit and low limit are set correctly on my aquastat?

Question

I have a boiler that is only providing heat for my forced hot water baseboard system (4 zones). I've always thought that the high limit on the aquastat was too low (the temperature on the boiler reads around 145 when the boiler shuts off). Most of what I've seen on heating sites recommends 180 or higher.