Every pirate movie ever made has a peg legged member of the scallywag crew. And who could forget Captain Ahab who lost his leg to the great white whale Moby Dick. Argh. 

Yes sir the peg leg has been around a long time and has served its purpose well. Actually the peg leg is still around today in another duty.  Not as a limb replacement for obsessed whale hunting seamen, but as an important part of gas piping.

Natural gas or propane is referred to often as the clean fuel and for the most part that is essentially true. When feeding gas through a network of pipes and holding devices some dirt is bound to find its way in the system.

Gas burners like the ones on a water heater have small orifices which can clog fairly easily. Because a miniscule amount of debris can be in those pipes a simple yet effective device must be added to the piping just before the water heater, the drip leg.

The drip leg is nothing more than a length of pipe fitted from the bottom of a pipe Tee. The gas comes in the top of the Tee and out through the middle into the water heater. The drip leg is the bottom pipe with a cap. Drip legs would also be found on gas furnaces and boilers.

Looking at the first photo you can see that this water heaters piping is missing its drip leg. The bottom photo is a nice example how a good install should look with the drip leg.

So next time you're watching Pirates of the Caribbean think to your self, does my water heater have a leg to stand on.

James Quarello
NRSB #8SS0022
JRV Home Inspection Services, LLC

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