The UPS whistles constantly, the red light is on, what should I do? You have noted that your INFOSEC UPS whistles constantly. Additionally, the red light of the UPS remains lit. In such a case, we recommend you contact the INFOSEC UPS SYSTEM after sales service. INFOSEC UPS SYSTEM after sales service on + 33 (0)825 091 702 (0.15 € all taxes included/min) hotline@infosec.fr It is alsp possible to use the contact form on the website.