This Starfrit Electric Kettle 1.7L purchased recently worked well for a month or so and then the automatic "stop boil" feature no longer shuts off and continues to boil non-stop until the lifted off the base. The automatic stop-boil safety feature no longer operates as stated. Is this a guaranteed requirement of the water kettle, and can it be repaired, or will the store replace the kettle as a warrantee item? ....(signed) E.J. Dueck