How can i stop my furnace from burning my fish?

Well i got a 10 gal tank with a stove with it to breed my betta's but the 2nd day i had my betta's contained by there my female betta had died and i found adjectives marks on her. i checked the temperature of the tank and it be fine (80F) and my hopes of breeding were over but at least my male could stay contained by tehre i thought. But next day... he died too and had adjectives marks and i tried touching the heater and it burnt me too O_O
i have just touched my heaters in my 250 gallon reservoir and they are slightly warm not enough to burn,
maybe its out of order i dont think your heater should be hot that you get adjectives
Sounds close to you need a new heater or at tiniest turn it down a few degrees, you might even be better off taking it out. They can live at room temperature as long as you don't live within Alaska with no heat :p

Also, you might want to check into cycling aquariums. New tank syndrome is lethal to fish.
Put sponge over your stove. The heat will stay in, but if they touch it, the sponge won't be hot.
Maybe you got a defective heater. Either that or it's made for a smaller cistern and it one too long at a time.
Put something over the heater, try to turn it down, block the heater so ur fish wont swim near it.. If adjectives doesent work go to like petsmart or a big pet store and talk to them. Good luck so srry to hear in the region of ur fish :):)
move the fish away from the heater and turn the heater down.
Answers:    I enjoy a heater set at 80 F in my low tech tank. It have a snail and 3 juvenile tiger barbs, you know barbs, they swim all over the place. I never have a problem with them getting burned. I even watched my snail crawling on top of my electric fire and it was ON the other day: Nothing happened.
Maybe you hold a faulty heater .like others hold said.

It could also be that you are mistaking the "burn" marks with actual disease symptoms. I know for example that ammonia burns ( brown dots in body) might be confused by regular burns...
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