EZAir warrants the mail generator that produces the ozone for 4 years. Extended warranty is availible for $175.00 ,25 years plus the 4 years. The customer would pay for the shipping to and from. This would be estimated to be in the ball park of around 25.00 dollars. That is that simple. The unit is made to run 24/7 for years and years. Every once in a while there is a flaw in the generator and a unit would go out in a year or two. This would be covered. Whats not covered is water damage, breaking the seal for the unit that would allow it to be opened.