Hello everyone. I am really struggling to find help to diagnose my 18 yr old Hayward H250 ED2 natural gas pool heater. I am getting the IF error code after the standard trying three times to light. We use our heater a whole lot. We also used it starting out this pool season until I started having the issue. Locally I can't get any help to have someone look at to give me a diagnosis or tell me it's time to purchase a new. Which I am totally o.k. with due to the age and how much we have used it over the years. I have watched every youtube video I can find, looked for spider webs, tested every switch, replaced the ignitor after not being able to come up with the 500mv reading that I was reading about. But, even after replacing the ignitor I still can't come up with that reading. So I was thinking maybe control board?? But not sure it's worth investing in that considering the age. I do have rust that I assume has come from the burner tubes, but from what I can see they still look in tact. Any advice would be greatly appreciated!