Thermostat function

[PMReef]

Hello, can someone answer me this question please?

I have a 800 watt true temp thermostat in my tank. Suddenly it stop producing heat and I check it and I cleaned it and it started producing heat. The digital controller on the other hand is malfunctioning, it displays the wrong temperature and I think it stop working correctly since never gets to the desired temp. So my question is If I power the heater without the digital controller what is the maximum temp it can reach?

Dont want to over heat the tank

 

[Screwgunner]

It will fry your tank. Get a couple back up heaters till you get a new controler. They say you should replace heater every year.