I ran a 200-350lb laundry bin up on the back of my heel this afternoon. there is already bruising/30min-1hr later, and a burning sensation is it brok?

Ouch: There's a chance it could be broken, especially if it was a direct hit--it could just be a bad contusion and an inflamed/injured achilles tendon. The burning sensation is probably a bruised nerve. I would go see a podiatrist to get an x ray and examination. In the meantime, rice therapy (rest, ice, compression, and elevation) with anti-inflammatory medication.

Doubt it: Most heel fractures require a fall. The bruising would be expected. More than likely you bruised your achilles' tendon. I would ice and maybe even use a crutch bud you have pain with weight bearing tomorrow, an x-ray would be appropriate.

Go get checked: Get x-ray. Get evaluated. That's alot of weight and blunt trauma can cause a fx or rupture of the tendon. Error on the side of caution and see a doctor.