No spark at the plug
- The Ignition device (transformer) is
not grounded. Clean the point where the box connects to the frame of
the heater and re-attach. Check for continuity.
- The ignition device has power going
in- no spark coming out. Since you have already determined that the
box is grounded, then the ignition device is defective- replace.
- There is no power into the Ignition
Device but there is power into the Safety Control (reset). The Safety
Control either has a bad connection or is defective- repair or