Heater acting up

I don't know if my heater is on its way out or not, but it just stops working every few days... Whenever I do a water change (not saying this has anything to do with it, but it happened twice so far) the heater light remains on, however it has a second light that indicates whether or not it's heating, and that light doesn't come on. Whenever I unplug it, wait a few seconds, and then plug it back it the heater works fine. I have no idea what's going on here, but it's getting kinda annoying. Any thoughts? Are these normal symptoms of a dying heater?

Thanks

Should turn off heater while doing a wc; if the unit is causing doubts in dependability, replace it.
I've seen ruptured units on google. I'd rather use a questionable unit for heating up bucket water than tank water.

Sounds like you should get a new heater to me, or put a 2nd one in the tank as a back up. I have 2 in my tank and i'm glad i did, one crapped out on me and the other one kicked in to do the job.. What kind of heater is it ?? I know if it's a marineland heater watch out.. There's loads of stuff on mfk and google about them blowing up and killing all your fish. I have 2 of them and have 2 new Ebo Jaegars on order right now from Dr Fosters to replace them.

If it is a Marineland Visi-Therm Stealth or Deluxe, you can email them with the problem and date-code on the unit and they will send you a new one. They are guaranteed for life. I recently had an eratic Stealth replaced by them - no receipt required.

The heater is a metal, 300W Sunlight Supply, Inc. I may do as you guys say and just buy a backup in case th is one decides to crap out on me. One thing I noticed was that the rubber rings/suction cups that attach to the tank have warped quite a bit recently... Wonder if it's getting just too hot for the one to handle :/ Thanks for the replies, everyone!