Manufacturers Know Corrosion Is a Problem
This isn't CoilShield's claim—it's direct from manufacturer documentation. Every major HVAC manufacturer either explicitly warns about corrosion risks in their installation manuals or excludes corrosive environments from warranty coverage. The evidence is clear: manufacturers acknowledge that corrosion is a real threat to coil longevity.
Installation Manual Warnings
Manufacturers include specific warnings about corrosion in their installation manuals, acknowledging the risks that can lead to premature coil failure:
Carrier/Bryant: Galvanic Corrosion Warning
"Take precautions to ensure Aluminum tubes do not come in direct contact or allow for condensate run off with a dissimilar metal. Dissimilar metals can cause galvanic corrosion and possible premature failure."
Carrier and Bryant explicitly warn installers about the galvanic corrosion risk when copper and aluminum come into contact. This is a direct acknowledgment that the electrochemical reaction between dissimilar metals can destroy coils.
Lennox: pH Sensitivity and Coastal Cleaning Requirements
"When cleaning coil, keep pH of cleaning solution between 5 and 9... Corrosive buildup (such as salt) should be cleaned as required but no less than several times per year in coastal environments."
Lennox acknowledges that aluminum coils are vulnerable to pH extremes and requires frequent cleaning in coastal areas. This warning recognizes that salt buildup accelerates corrosion and that aluminum's narrow safe pH window (5-9) makes it vulnerable to common cleaning products.
Daikin/Goodman/Amana: Chemical Cleaner Warning
"Even a one-time application of these corrosive chemicals can cause premature aluminum evaporator coil failure. Any cleaners that contain corrosive chemicals including, but not limited to, chlorine and hydroxides, should not be used."
Daikin, Goodman, and Amana explicitly state that a single application of the wrong cleaning product can destroy an aluminum coil. This warning acknowledges that aluminum is amphoteric—attacked by both acids and bases—and that the safe pH window is narrow.
Warranty Exclusions: The Universal Gap
While manufacturers warn about corrosion risks, they simultaneously exclude corrosive environments from warranty coverage. This creates a gap: manufacturers acknowledge the problem but won't cover failures caused by it.
| Manufacturer |
Corrosion Excluded? |
Salt/Coastal Mentioned? |
Key Exclusion Quote |
| Carrier/Bryant |
✅ YES |
No |
"corrosive environments (rust, etc)" |
| Lennox |
✅ YES |
✅ YES |
"chlorine, fluorine, salt, urine, fertilizers" |
| Trane/American Standard |
✅ YES |
✅ YES |
Requires "Sea Coast Kit" |
| Rheem/Ruud |
✅ YES |
No |
"contaminated or corrosive atmosphere" |
| York/Johnson Controls |
✅ YES |
✅ YES |
Requires epoxy-coated coils |
| Mitsubishi Electric |
✅ YES |
✅ YES |
"sea- or salt-water" |
| Fujitsu General |
✅ YES |
✅ YES |
"salt air or spray, chlorine, fluorine, formicary" |
| Daikin/Goodman/Amana |
✅ YES |
See warnings |
Standard exclusions + chemical warnings |
What This Means for Homeowners
If you live in any of these environments, your warranty may provide zero protection for coil failures:
- Coastal areas (within 15 miles of salt water)
- Pool and spa facilities (chlorine explicitly excluded)
- Agricultural operations (ammonia, fertilizers excluded)
- New construction (VOC off-gassing creates formicary corrosion)
- Spray foam insulated homes (trapped VOCs accelerate corrosion)
- Industrial/chemical environments (any corrosive atmosphere excluded)
Even if your environment isn't explicitly excluded, manufacturers can deny warranty claims by attributing failures to "environmental factors" or "corrosive conditions."
The Contradiction
There's a clear contradiction in manufacturer documentation:
- Installation manuals warn about corrosion risks—acknowledging that galvanic corrosion, pH sensitivity, and chemical exposure can destroy coils
- Warranty documents exclude corrosive environments—refusing to cover failures in the very conditions they warn about
Manufacturers are saying: "We know corrosion is a problem, and we're warning you about it, but if it happens, we won't cover it."
CoilShield's Solution
CoilShield provides protection where manufacturers say 'not covered.' Our cathodic protection systems prevent corrosion regardless of environment—coastal, pool, agricultural, new construction, or spray foam homes.
When warranty exclusions leave you vulnerable, CoilShield ensures your coil is protected. We use the same proven technology that's protected trillions of dollars of infrastructure worldwide for 200 years.
Don't rely on warranty coverage that may not apply. Protect your coil with CoilShield's proven cathodic protection technology.
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