Cooked water heater...

[JFlo]

Recently, my water levels got low while the water heater was on (using propane, not electricity) and black soot came out of the water heater external exhaust, along with a burning smell. Anyone know what might have burnt, and what I might need to check?

 

[Trav_lr]

An insect nest/hive in the burner tube?

 

[Greg and Mary Brannon]

You said your "water levels got low." What do you mean, or how did you measure the water levels to know they were low?

Greg.

 

[TheLooks]

And low water will not make black smoke......That is something blocking the airflow in the burner tube and getting a real yellow flame.
I should clarify by burner tube I mean the curved tube just after the gas valve.....

 

[Kevin D Pem]

I have seen a puff of wind put the flame in the venturi and cause a temporary situation, but not permanent.