Friday, September 30, 2011

Water Heater

I recently had to clean out a sooted up oil fired water heater.  This first photo shows the inside of the heat exchanger after I was done cleaning it.  The heat exchanger is basically a large tube inside the water tank.  The inside of this tube has hundreds of these steel fins welded to it.  The oil burner is at the bottom of this tube and the hot exhaust flows up past all these fins and heats the water.

This photo shows the water heater.  In order to clean it out I had to remove the chimney from the top of the unit.  In this case the chimney was also tied in with a couple of boilers for heating the building.

When I first removed the barometric damper (the piece with the little door that flops around) from the chimney and looked inside this is what I saw.  The entire thing was plugged up tight.

After cleaning off the top and removing the core from the heat exchanger I could see that all of the fins were packed full of soot.  Compare this photo to the first one.  The cause of this all this soot is an improperly running burner.  Typically the nozzle wears out or gets plugged up, this causes the oil to burn erratically and produce soot.  Once a little soot accumulates in the heat exchanger it starts to restrict the air flow.  This restriction in airflow then causes the burner to run worse, this makes more soot and restricts the airflow further.  Eventually the whole thing ends gets clogged up solid and someone calls me to fix it.

I used a long wire brush and a shop vac to clean the soot out.  The wire brush has a long flexible handle that allows it to be pushed between all the fins from the top opening.  It takes a lot of scrubbing to get into every little space.

I also removed the gun from the bottom of the tank so that I could clean the soot out of it.  On this unit the oil lines are plumbed from a Tigerloop with flexible lines.  This allows the gun to be removed without disconnecting anything.
To avoid these problems you should change the nozzle and filter annually and if anything seems out of the ordinary have the burner adjusted by a qualified technician.

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