I have been using the same stove for about 20 years now, and that includes during harvest season when I sometimes fire up a pot that will hold about 16 quarts. That's a four-gallon pot or, in other words, a pot that is only a little smaller than a five gallon paint bucket. To date, I have replaced ONE burner on that stove, and it wasn't the big one that gets the paint bucket - sorry, pot. It was the little one at the back where I sometimes heat water for tea.
What other points do these failures have in common? Are they all the same cheap stove? Are you using low quality repair parts because they're less expensive?