I haven’t seen any tankless water heaters that have bonding like the code book. Was it any recommendation or did they missed?
Were the water lines copper or PEX?
1 Like
Enter the Model/ serial number and you can find what you are looking for.
Document Finder - Rheem Manufacturing Company
1 Like
Are you referring to the electrical system bonding, or the flexible NG pipe bonding?
Also, you are showing two brands of TWH’s. Are both on this property, or are you showing examples. or???
Need more specific and clear details.
1 Like
The bonding jumper to the gas line as depicted below is not required by the NEC.
We’ve covered this before. The NEC doesn’t provide/require gas line bonding. That requirement comes from the gas line manufacturer. The NEC is satisfied with the ground/bond provided by the grounded electrical cord provided with the appliance.
2 Likes
Thanks you very much
I asked my AI assistant what they thought about the situation, here was the dialog.
JB: write a summary concerning residential Tankless water heater bonding from the perspective of the NACHI Standards of Practice located here… Home Inspection Standards of Practice - InterNACHI®.
Dolphin_Mixtral: The National Association of Certified Home Inspectors (NACHI) has established a set of Standards of Practice that home inspectors should follow when evaluating residential properties, including the installation and bonding of tankless water heaters. Here is a summary of the NACHI standards related to residential tankless water heater bonding:
Inspection Scope: A home inspection should include an evaluation of the visible components of a tankless water heater system, as well as its proper installation and functioning. This includes checking for the presence of a bonding conductor connecting the unit's metal components to other grounded systems within the residence.
Bonding Conductor: The home inspector should verify that a bonding conductor (typically a #6 or larger copper wire) has been installed between the tankless water heater's non-current-carrying metal parts and other grounded systems in the building, such as gas appliance piping, metal conduit, and plumbing.
Bonding Points: The home inspector should confirm that bonding points are correctly identified on the tankless water heater according to the manufacturer's installation instructions. Common bonding locations include the cold water inlet pipe, the hot water outlet pipe, and the unit's chassis or enclosure.
Bonding Conductor Connections: The home inspector should assess the connections between the bonding conductor and the identified bonding points on the tankless water heater system. These connections should be secure, corrosion-free, and made using a clamp or ring terminal as recommended by the manufacturer.
Bonding Conductor Length: The home inspector should verify that the length of the bonding conductor does not exceed 50 feet to ensure proper bonding.
Multimeter Test: The home inspector should use a multimeter to test the bonding of the tankless water heater system, ensuring that the potential difference between any two points on the system is less than 2 volts AC. If necessary, adjust or replace connections to achieve this goal.
Regular Maintenance: The home inspector should recommend periodic inspections and maintenance of the tankless water heater system, including checking the integrity of the bonding conductor and connections.
By following the NACHI Standards of Practice, a home inspector can provide an accurate assessment of residential tankless water heater bonding to ensure safety and optimal performance over time.
JB: It has been pointed out that The NEC doesn’t provide/require gas line bonding. That requirement comes from the gas line manufacturer. The NEC is satisfied with the ground/bond provided by the grounded electrical cord provided with the appliance. which would indicate that #6 Bonding Conductor is not necessary, please revise your recommendations based on this new information.
Dolphin_Mixtral: Based on the clarification provided regarding gas line bonding requirements, it appears that the National Electrical Code (NEC) does not specifically require a #6 bonding conductor for residential tankless water heaters with gas lines. Instead, the NEC is satisfied with the ground/bond provided by the grounded electrical cord accompanying the appliance. In this case, the need for a separate #6 bonding conductor may not be necessary.
However, it’s essential to consult the manufacturer’s installation instructions for your specific tankless water heater model to determine if a #6 bonding conductor is required or recommended by the manufacturer. Additionally, always adhere to local building codes and safety standards when installing gas appliances in residential settings.
To summarize, the NEC does not specifically require a #6 bonding conductor for gas-line residential tankless water heaters, as long as the ground/bond provided by the grounded electrical cord accompanying the appliance is considered sufficient. Always consult the manufacturer’s installation instructions and local building codes for specific recommendations regarding bonding conductors in your particular case.