PlanetCatfish.com

I recently started having problems with a 150 watt Rena Cal excel heater in a 30 gallon aquarium. It doesn't shut off when it reaches the set temperature and overheats, even when I turn it all the way down to the lowest temperature on its thermostat. I can unplug it during the day, but I'm afraid it will get too cold at night to go without a heater. I've only had it for about 6 months. I was wondering if anybody else has had this problem with this particular brand or just in general before I go out and buy another one. Also, any suggestions on brands available in the US that might be more reliable?
Thanks!

They are usually good heaters, and at 6 months it should certainly still be in warranty. Get in touch with them, explain the situation and see what happens.
Pete