Is it possible to insure the purchase / extend the warranty?

Eberspacher and Webasto heaters and heater kits include a standard 2-year warranty, with the option to extend coverage by an additional year with Heatso.

Extended warranty coverage applies to heaters operating up to 2,000 total hours of use. Extended warranty is not available for heating systems used in industrial applications, for systems expected to operate more than 1,000 hours per year, or for coolant heaters with an output exceeding 18,500 BTU.