High sparking initiator compositions with a controlled amount of power are disclosed. The initiator compositions comprise a metal containing oxidizing agent, at least one metal reducing agent, and a non-explosive binder. Low voltage igniters that provide bidirectional plumes upon ignition are also disclosed. These igniters have a electrically resistive element positioned across a hole in a support which directs the plume. These igniters and compositions are useful in the actuation of solid fuel heating unit, in particular, sealed heating units.