If you aren't experienced in working with large gas appliances (pool heaters), you should not be adjusting things to force them to work. Minor cleaning is fine, but troubleshooting and repair should be left to an expert in the field. Having one light and then cause a fire or injury is a very real risk that you face when dealing with these appliances.

Remember, while a pool can be great fun, relaxation, entertainment, etc., we are still mixing people and their environment with water, electricity, and explosive gas. Safety is , and should be, the number one concern, not saving a few (or a lot) of dollars.