Immersion Heater thermostats probs

[verdigrey]

Hello everyone , In the last few weeks iI have replaced immersion heaters for 2 customers and both of them have tripped out the safety cut out device . I had set them to 65 o C . I just lowered them to 60o & so far they havent cut out again . But they shoulnt cut really till the temp' reachs 90o C . The heaters are made by Banico , has anyone had this problem please . Cheers . By the way the boilers are turned off so the only heat is coming from the immersion heater itself . 🙂