please put your temp sensor in the same chamber as the heater, i just had an issue where my hosed poped off of my bio-pellet reactor and spilled into my backup/floor and drained the system enough to where there was no water flowing. Heater came on in one chamber as the temp sensor was in another chamber, needless to say the water got very hot in the chamber. i only noticed it when i saw steam comming from the sump. Glad i was at home at that time