Heater cabinet shows signs of corrosion, rust streaks, or paint bubbling, especially near the base.

Safety: Turn off power and gas before detailed inspection.

Steps:

• Check condensate drain: On condensing models, ensure the condensate trap and drain line are not leaking onto the cabinet. Repair or reroute as needed.
• Relocate chemicals: Do not store chlorine, acid, or other pool chemicals near the heater. Fumes can corrode metal surfaces.
• Inspect for leaks: Look for water trails from the heat exchanger or headers that may be causing corrosion.

Severe corrosion may compromise structural integrity and combustion air paths; a technician should evaluate whether repair or replacement is appropriate.