The grates surrounding your air conditioner outside should be inspected often. Fallen leaves and twigs that blow in during a storm can get trapped in these grates. Along with this debris, you may spot rust stains, which are indicative of a bigger problem. Here are some causes for these rust stains and the repairs that can be made by an HVAC contractor.

Evaporator Coil Is Rusted and Filled with Holes

The evaporator coil inside your air conditioner's condenser unit (the box outside) is metal and frequently exposed to the elements. Over time, it rusts just like any other metal item would, and eventually, it begins to get holes in it. Because condensation from the condenser passes through this coil, the condensation has a tendency to leak out the rusted-out evaporator coil's holes, leaving a rust-stained mess. This drips out onto the grate that covers the box/unit and onto the concrete slab underneath. The HVAC contractor can attempt to replace the evaporator coil so long as the rest of the unit's components are in good shape. If all of its components have something wrong with them, you may need a brand-new air conditioner.

The Condenser Is Shot

If it is not the evaporator coil, it is the condenser. When a condenser is so shot that it is covered in rust and peppered with holes and flaking rust, you will need a new air conditioner. The reason for this is that most condensers, especially ones to replace older A/C models, cost almost as much as a new air conditioner, and after labor expenses, it is not cost-effective to install and replace just the condenser.

The Fan Blades Rusted

Of all the things to rust, the fan blades in the top of the unit are most likely to rust. Newer air conditioners now use different metal alloys or plastic blades so that rust is not a problem, but older air conditioners have metal blades that will rust easily. You can see the fan blades just by looking at the top of the outside box. When the air conditioner is not running, these blades will look like someone threw tomatoes into your A/C unit—the rust just peppers and covers the blades. If this is the only rust that can be found when your HVAC contractor opens the box unit, then he or she can replace the fan and restore the unit to its former self. Click here to find out more.