It might seem harmless to leave your outdoor HVAC unit uncovered through fall and winter, especially when manufacturers claim these systems are weather resistant. That doesn’t mean they’re invincible. Moisture, pests, and yard debris can quietly start the kind of damage that’s expensive to undo.
Seasonal prep is important, so learn how to protect the equipment that keeps your home comfortable. If you’re not sure where to begin, Frasier’s Plumbing, Heating, & Cooling in Rhinelander, WI can help you determine the best protection plan. Keep reading to avoid mistakes that cost more than a cover ever would.
Weather Resistant Does Not Mean Damage-Proof
Manufacturers design outdoor HVAC units to survive different weather conditions, but that does not mean you can ignore them once summer ends. Rain, sleet, ice, and rapid temperature swings may not stop your unit from turning on, but they still wear down the components inside. The metal cabinet can trap moisture inside instead of shedding it. When moisture lingers, rust takes hold. That rust does not stay on the outside, either. It can creep into coils, fasteners, and electrical connections.
Puddles that freeze near the base can shift the unit slightly, bending lines or loosening mounting brackets. If you live somewhere with fluctuating winter temperatures, that freeze-thaw cycle will accelerate the damage. Covering the unit or at least blocking off the top can reduce the amount of water that seeps inside.
Leaves and Twigs Can Wreck the Fan Assembly
Autumn seems harmless until you peek inside an HVAC unit that sat uncovered under a tree. Leaves don’t fall politely around the base. They slip through the top grate and settle near the fan motor. When that happens, airflow slows down, the fan strains harder, and the whole system runs hotter. The insulation on the wires may even start to break down from the heat. In the worst cases, the motor overheats and short-circuits. All that results from some soggy leaves.
Small twigs are no better. They lodge between the fan blades and the housing, which can throw the blades out of balance. Once those blades start wobbling, the motor pulls more power and begins to wear faster. By spring, you might not realize why your fan is making noise or struggling to start. You just know the air is warm when it should be cold. That kind of problem costs more to diagnose and fix than it would have to prevent.
Pests Like a Covered Space Too Much
It might feel like covering your outdoor HVAC unit would attract pests, but the opposite is usually true when the system is left exposed. Rodents and small animals are not drawn to covers. They are drawn to shelter. When a system sits uncovered through the winter, it becomes a tempting nesting spot. Leaves and debris drift inside and make the base feel soft. Wiring insulation offers a warm, chewy surface.
You won’t see the damage right away. It usually starts as something minor, like a frayed wire or a chewed sensor line. The compressor might refuse to start because the contactor is shorted. Or the fan might spin erratically because the control board wiring was gnawed through. Once you discover a pest issue in spring, the fix can take longer and cost more than a regular tune-up. Even worse, pest urine and droppings can corrode the metal base or lead to mold inside the cabinet.
Frozen Water Inside the Base Can Crack Connections
It is not the presence of water alone that causes winter damage. The freeze-thaw cycle is what breaks things apart. If water seeps inside the unit and collects at the bottom, it expands when frozen. That pressure can shift copper lines or flex the base plate. Electrical wiring might get pinched or pulled as things move ever so slightly out of alignment.
Over time, those small shifts cause electrical faults or refrigerant leaks. If a coil rubs against something it wasn’t touching before, a leak might show up during the first spring startup. Cracked fittings or loose wires also make it harder to diagnose startup issues. It all circles back to how exposed your unit was when the weather changed. Covers help block snow, freezing rain, and sleet from entering through the top or sides.
Buy Your HVAC Cover Today
Leaving your HVAC unit exposed might not seem like a big deal today, but small things like debris buildup, freezing moisture, or rodent nests can seriously damage your system by spring. Protecting your equipment before issues begin is always cheaper than fixing it later. Our company offers seasonal inspections and maintenance visits to help protect your system and keep everything running the way it should.
Schedule your maintenance visit with Frasier’s Plumbing, Heating, & Cooling now, and stay ahead of preventable repairs.
