I have an older Sta Rite heater.. has worked great the last 7 years. Now, when I turn on the heater, it turns on, shows the current water temp on the LED, the blower comes on but it does not light. It continues for about 30 seconds and then shuts itself off. I thought it might be the igniter so I replaced it but it did not change anything. I also took the opportunity to clean it via compressed air.. no mice nests or anything, just lots of dust. As far as I can tell, it's not throwing any error codes; nothing on the LED display and no lights underneath the LED cap. I've read that if the gas pressure isn't high enough it won't fire- but nothing has changed there. All help appreciated.