Heater cabinet shows signs of rust, especially around the base and vent connections.

Safety first: Turn off power and gas before performing any structural repairs.

• Improve drainage: Ensure the heater is installed on a solid, level pad above grade, with water draining away from the base.
• Check condensate drain: On condensing models, verify that the condensate drain line is clear and properly routed to a drain.
• Treat rust: Light surface rust can be cleaned and treated with rust-inhibiting primer and paint. Severe structural corrosion may require cabinet or base replacement.
• Environmental protection: In coastal or chemical-heavy environments, consider additional shielding or relocating the heater if feasible.