I have 6 of the optimus and all of them have fused thermostat contacts! ! ! and the outher parts of all units are in good order. Im tolled that is no parts to replace the bad parts ! ! !. I have two [2] older units that have metel NOT plastic and thay steel working today I need 6 thermotats to repare the units . also note tip over cut off don`t work ! ! !at all. I have taken back for replacement and the same thing happens. so please send replacement parts as needed. Thank You Gerald Bowker Sr 208-946-**** or jerrybowker@***l. com