You hear clicking but there’s no ignition.

First thing to do in this case are the following observation checks which do not require any tools, instruments, or taking anything apart.

1- Check the spark color. A healthy ignition system will produce crisp blue sparks. A weak ignition system, on the other hand, will produce light blue, almost white sparks. The following two checks can be made by switching the suspected burner with a known operating burner:
1. Ignite the burner with a match to verify proper gas supply and air shutter adjustment. Make sure the flame is a clean blue flame, not yellow and sooty.
2. The gap between the ignitor and the burner base is too large. It should be about the thickness of two dimes.
3. Gookus is caked on the ignitor or burner base. Clean the burner caps, heads, flame spreaders, ignitors…that whole area. HINT: do not use stuff like Comet because you’ll gunk everything up big time. Warm water and Basic-H are a good choice.

These following two checks are done by physical inspection “under the hood”:

1. Loose wiring connections at the ignitor, the grounding strap, or spark module.
2. Broken or pinched ignitor wire between the burner and module.

2. Check the spark frequency. Say what? A healthy spark system will crank out three to five sparks per second. If yours is a lot slower than this, then the prime suspect is reverse polarity at the 120vac outlet the range is plugged into.

You hear clicking but it’s erratic.

This is usually a bad spark module. But first, verify that the outlet polarity is correct before you change the module. This flow chart gives you further guidance on troubleshooting erratic spark problems.

Normally the spark is created by a battery and the fix could be as easy as changing this and/or cleaning up the contacts to insure good connection.