Hot water heater purges, glows, lights then immediately shuts off ; does this 3 times and locks out. Checked for vent blockages, all is good . Any suggestions

Power vent systems can be super tricky to troubleshoot! My best advice (guaranteed to save you time and frustration) is to contact RUUD/RHEEM tech. support so they can help you resolve this quickly:

Call tech. support directly @ Phone: 1-800-432-8373

These guys are fantastic and will quickly walk you through every step needed!

Good luck!

Mark