canard wrote

From past experience, it is the burners that are dirty.

It wasnt when I had that happen, just slow to ignite.

And after 14 years, its unlikely that she is still
waiting for you to tell her what to do about it.

Just turn the furnace off (electrically with the switch on the wall and
put the gaz knob to off and of course put the thermostat at the lowest
setting. Get a good light and a few basic tools and remove the burners and
vacuum them ir even better use a copper brush at the end of a drill to
clean all the burner's openings well. Replace, put the bottom door back if
you removed it (to push on the safety stop switch), put on pilot, relight
with a barbecue lighter, count to 100 and keep your finger on the pilot
buttin, when lit put on ON and then put your thermostat higher and then
listen and it should not bang anymore. If it does clean the pilot as
outlet and you can even try this first but if you pilot flame is good it
should not be the problem.

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