Broken heater! Help!

[That Fish kid]

Recently I noticed the temperature in my aquarium at 84degrees. Yikes! The heater is set for 78 but thermometer says 84. The fish don't seem to mind but could this become a problem later on for them? Is there any way to salvage this heater or should I use a new one?

 

[Lt.]

Your heaters thermostat is broken, so is mine. But I figured out how far off the temperature on the dial and tha actual temperature was, and set it so that it maintained 78 like I want. But the temp say 84 on my heater.

 

[That Fish kid]

I'll try that.