Archive for the ‘Sediment Traps’ Category

Sediment traps at water heaters and furnaces

Tuesday, November 22nd, 2011

A question I get asked about frequently is what is a sediment trap, and what is its purpose. I have installed a number of water heaters over the years and have found that within the last 4-5 years, all water heater manufactures recommend installing a sediment trap. If you do not install a sediment trap on your new water heater, it will void the warranty. The installation of this trap at the water heater as well as the furnace is also a requirement of the Claifornia Plumbing Code; 1212.7


The installation of a trap is a safety feature, and can extend the life of your water heater or furnace. What a sediment trap does is keeps moisture and small particles that may be in the natural gas or propane from clogging the small orifices that are within the gas valve assembly at the appliances, and the burners as well. The gas valve assembly for a water heater is where the temperature selection knob is located. If any of these orifices get clogged, the pilot for a water heater, and or the burners for both the water heater or furnace will not operate correctly which could lead to a hazardous condition.


  A sediment trap should be as close to the water heater or furnace as possible, but down stream of the shut off valve for these gas fired appliances. This is so the gas can be shut off and the trap checked if necessary. The trap is installed where the gas flow must make a 90 degree turn just before the gas valve assembley. In order to prevent clogging, moisture or particals in the natural gas, or propane gas will settle in the trap. This trap is simply a short length of pipe (or nipple) facing downward that is a minimum of 3 inches long, is threaded at the bottom that is capped.This is a very inexpensive component, and only takes a few minutes to install, but provides safety, and prolongs the life of the appliance.