Issue Identification
Rheem has identified that certain ULN atmospheric models, produced in limited quantities, may exhibit pilot outages. This condition can lead to intermittent operation of the burner.
If you are experiencing this issue, please verify the pilot assembly's position using the guidance provided below.
Pilot Assembly Positioning Details
The following information and diagram description illustrate the correct placement for the pilot assembly on ULN residential gas atmospheric heaters featuring a mesh-type radiant burner. An improperly positioned pilot assembly can cause issues such as the water heater failing to remain lit.
Diagrammatic Representation of Correct Pilot Position:
The visual guide indicates the precise alignment of the pilot assembly relative to the main burner mesh. Key measurements and reference points are:
- Gap between Pilot Hood and Burner Mesh: The recommended gap is between 0.18 inches and 0.24 inches. A practical method to achieve this is by stacking three US nickels or three US quarters. This stack approximates 0.231 inches in thickness.
- Thermopile to Burner Measurement: The distance from the top of the thermopile to the bottom of the burner should be between 1.035 inches and 1.315 inches.
- Pilot Hood to Burner Measurement: The distance from the top of the pilot hood to the bottom of the burner should be between 0.70 inches and 1.0 inches.
Note on coin thickness for measurement: A US nickel has a thickness of approximately 0.077 inches. A US quarter has a thickness of approximately 0.069 inches.
Installation and Verification Procedures
After mounting the pilot assembly, ensure the following:
- All mounting screws are securely tightened.
- The pilot bracket assembly is firmly attached.
- The spacing dimensions are correct, specifically:
- A gap of just under ¼ inch between the pilot hood and the burner mesh (achievable with 3 nickels or 3 quarters).
- The top of the pilot hood is approximately ¾ inch from the bottom of the burner.
- The top of the thermopile is approximately 1 3/16 inches from the bottom of the burner.
Resolution and Further Assistance
Once the pilot assembly is confirmed to be in the correct position according to these specifications, the ignition sequence can be followed as detailed in the unit's instructions or the Use & Care manual.
Correcting the pilot position should clear any associated gas valve error codes, enabling proper burner operation.
Should you have any questions regarding this bulletin or encounter a unit with this specific problem, please contact Rheem Technical Service or Rheem Customer Service.
