When the HVAC did not have any PC boards the surge protection was not needed, but when manufacturers started using electronics, this requires protection against lightning. Most manufacturers use some form of electronics on modern HVAC equipment.
2 HVAC systems for home - ideas?
new home hvac system in southwest,pa
Is my HVAC high limit switch working or not? Two HVAC pros said it is.
Need Help on choosing NEW HVAC system!!!