hi there, I'm wondering if this part wears out over time. We are having trouble lighting the stove with this knob. I can see that the igniters are sparking, but I don't know if the sparks should be more robust. Is there potentially a different issue that I should be looking at? Thanks in advance! Cory Oh and before I get any jokers saying to check that I haven't run out of gas, it works fine once I get my lighter.