Here are the install and service instructions for the B1HA and B1KA boilers. 

Hard Reset Procedure:

Reset activation (reset burner control unit) Touch R for approx. 2 sec. If the fault has been removed, the fault symbol “  “ disappears and the default display is shown or a further fault message is displayed. If the fault persists, the fault message appears again.

If LP to Natural Gas kit is needed. Part# 7637718