That's a dirty job! The best way is to pull the heat exchanger out and power wash it. It is not a DIY for everyone because it involves dis- assembly of the heater, and removing switches and sensors from the exchanger. If you are mechanically inclined it is not too hard, just pay close attention to how you dis-assemble it. Usually the hardest part is getting the cabinet put back together correctly!
When power washing find a place where it won't matter if if carbon black goes everywhere. It will look like someone broke open a bag of copier toner (remember that?).
The deeper issue is why did the heater soot up like that? The most likely reason is that the heater has not been getting enough gas. That will cause the yellow flame that deposits soot on the exchanger. Proper gas supply will produce a blue flame that will not soot.
Low gas is usually associated with an undersized gas meter or the gas line to the heater is too small in diameter. A plumber can tell you if this is the issue.
Answers & Comments
That's a dirty job! The best way is to pull the heat exchanger out and power wash it. It is not a DIY for everyone because it involves dis- assembly of the heater, and removing switches and sensors from the exchanger. If you are mechanically inclined it is not too hard, just pay close attention to how you dis-assemble it. Usually the hardest part is getting the cabinet put back together correctly!
When power washing find a place where it won't matter if if carbon black goes everywhere. It will look like someone broke open a bag of copier toner (remember that?).
The deeper issue is why did the heater soot up like that? The most likely reason is that the heater has not been getting enough gas. That will cause the yellow flame that deposits soot on the exchanger. Proper gas supply will produce a blue flame that will not soot.
Low gas is usually associated with an undersized gas meter or the gas line to the heater is too small in diameter. A plumber can tell you if this is the issue.