The installation of a drip leg or sediment trap on a propane water heater is a topic of debate among professionals, with some considering it essential and others viewing it as unnecessary. The primary function of a drip leg is to collect condensation in a gas piping system, while a sediment trap collects sediment, rust, or debris that can clog a gas appliance burner and cause a malfunction.
Understanding Drip Legs and Sediment Traps
A drip leg, also known as a sediment trap or dirt leg, is a vertical section of pipe installed in a gas line, typically near the appliance inlet. Its purpose is to collect any condensation, debris, or contaminants that may be present in the gas line, preventing them from entering the appliance and potentially causing issues.
The plumbing code has undergone changes in recent code cycles, causing confusion regarding the installation location of sediment traps. According to the 2016 California Plumbing Code (CPC), sediment traps should be installed after the appliance shutoff valve but before the flex connector to facilitate cleaning. However, some plumbers believe that drip legs, sediment traps, and dirt legs are interchangeable terms, while others argue that they serve different purposes.
Practical Considerations
From a practical standpoint, installing a drip leg on a water heater may not be necessary due to the cleanliness of today’s gas supply. However, from a code viewpoint, it may be required in some jurisdictions. Drip legs or sediment traps are typically installed as close as possible to the inlet of every appliance that will fire while unattended, such as water heaters, furnaces, and pool heaters.
In the case of a propane system, drip legs are more important due to the potential for oil logging from bad propane. It is recommended to ensure that a drip leg is present in such systems. The installation of a drip leg or sediment trap can prevent rust or particles from entering the gas valve, which could over time prevent the valve from sealing tightly when off.
Code Requirements and Regulations
The specific requirements for the installation of a drip leg or sediment trap on a propane water heater can vary depending on the local building codes and regulations. It is essential to consult with local authorities and follow the applicable codes to ensure compliance.
According to the 2021 International Fuel Gas Code (IFGC), Section 409.5, “Where a sediment trap is not incorporated as part of the gas utilization equipment, a sediment trap shall be installed downstream of the equipment shutoff valve as close to the inlet of the equipment as practical.” This requirement applies to all gas-fired appliances, including propane water heaters.
The 2021 NFPA 54 (National Fuel Gas Code) also addresses the installation of sediment traps in Section 8.3.4, stating that “A sediment trap shall be installed as close to the inlet of the appliance as practical, but where the sediment trap is not incorporated as part of the appliance.” This further reinforces the need for a sediment trap or drip leg on propane water heaters.
Potential Issues and Maintenance
The installation of a drip leg or sediment trap can prevent rust or particles from entering the gas valve, which could over time prevent the valve from sealing tightly when off. This can lead to gas leaks, which can be a serious safety hazard.
It is important to note that the drip leg or sediment trap must be properly maintained to ensure its effectiveness. This includes regularly inspecting and cleaning the trap to remove any accumulated debris or contaminants. Failure to maintain the trap can lead to the same issues it was intended to prevent.
Conclusion
While the installation of a drip leg or sediment trap on a propane water heater may not be necessary from a practical standpoint, it is recommended from a code perspective and can prevent potential issues with the gas valve. It is essential to consult local codes and regulations to determine the specific requirements for installation and to ensure that the drip leg or sediment trap is properly maintained to ensure the safe and efficient operation of the propane water heater.
References:
– HVAC – Drip leg vs. Sediment trap – InterNACHI®️ Forum
– no drip leg on water heater – Love Plumbing & Remodel
– Drip legs for propane system – DoItYourself.com Community Forums
– Sediment traps/drip leg required for propane tankless heaters? – Reddit
– Should I install a drip-leg for tankless water heater? – Bogleheads.org