When is it considered renter's negligence?

[Stacy Weng]

I have a condo that's currently being rented out. A couple months ago, my renter contacted me saying the floor under the hot water heater was wet. Turned out it was b/c the water heater temperature was too high and the steam released from the relief valve made the floor wet. I told them to turn the water temp down and advised them to not keep the temp too high, esp since the weather was getting warmer.

This past weekend, they come back from vacation, and there's water gushing out of the relief valve, which ended up severely damaging the unit below since they were away. At first I thought it was just bad luck that the relief valve happened to break all of a sudden. But when I sent a plumber out to get it fixed, it turns out that the water heater temp was on high, which caused the water heater to overheat and burn out the relief valve. 

Since I had already advised my tenants to not keep the water temp on high, esp during the summer months, does this incident make it their negligence? I already started a claim with my insurance, but I'm wondering if this should be their responsibility knowing now that it was b/c they had kept the temp too high when they were advised not to?

Would this fall under renter's negligence or does it all fall on me? 

Thanks!

Stacy

[Wayne Brooks]

If the hot water heater didn't function properly at one of it's proper temperatures, it was defective.  That's like saying don't drive a car over 50 mph because it will overheat, due to a failing water pump.