Supply Gas Pressure Adjustment | Manifold Gas Pressure Adjustment |
Fire and Explosion Hazard
Do not use water heater with any gas other than the gas shown on the rating label.
Excessive gas pressure to gas valve can cause serious injury or death.
Turn off gas lines during installation.
Contact a qualified installer or service agency for installation and service.
Supply gas pressure shall be measured while the water heater is not firing (static pressure) and while the water heater is firing at full capacity (dynamic pressure).
If the supply gas pressure to the water heater is not between the required minimum and maximum values given in Table 4 on page 14 adjust the supply gas regulator as necessary. Adjust the supply gas regulator(s) per the regulator manufacturer’s instructions to achieve the required “static” and “dynamic” supply gas pressure.
Multiple Appliance Installations:
In multiple water heater installations or in installations where the installed water heater(s) share a common gas supply main with other gas fired appliances; the supply gas pressures shall be measured at each water heater with all gas fired appliances connected to a common main firing at full capacity.
On multiple water heater installations the supply gas line regulators shall be adjusted to provide gas pressure to each water heater within the minimum and maximum supply pressure requirements listed in Table 4 on page 14 with all gas fired appliances connected to a common gas main firing at full capacity.
Note: A pressure drop of more than 1.5” W. C. (0.37 kPa) when the Main Burner ignites is an indication of an inadequate supply of gas and can lead to ignition failure, rough starts and/or rough operation. If a drop of more than 1.5” W. C. (0.37 kPa) in supply gas pressure occurs when the Main Burner ignites, ensure the supply gas lines and regulator(s) are properly sized and installed. See the requirements for Supply Gas Regulator and Supply Gas Line on page 14. See Supply Gas Line Installation on page 39 and Supply Gas Regulator Installation on page 40. Ensure all requirements and installation instructions are maintained.
Fire and Explosion Hazard
Under no circumstances should the input exceed the rate shown on the water heater’s rating label.
Overfiring could result in fire or explosion.
Gas and carbon monoxide detectors are available.
Breathing Hazard - Carbon Monoxide Gas
Under no circumstances should the input exceed the rate shown on the water heater’s rating label.
Overfiring could result in damage to the water heater and sooting.
Gas and carbon monoxide detectors are available.
Breathing carbon monoxide can cause brain damage or death. Always read and understand instruction manual.
Ensure the "dynamic" supply gas pressure is above the minimum requirements in Table 4 on page 14 before any adjustments are made to the manifold gas pressure. Attempts to adjust manifold gas pressure during periods of low supply gas pressure could result in overfiring when the supply gas pressure returns to normal. See Supply Gas Pressure Adjustment on this page.
Note: Manifold gas pressure is
±0.3" W. C. from the listed values in Table 4 on page 14 call the technical support phone number listed on the back cover of this manual for further assistance.
Follow the steps below to adjust the manifold gas pressure on SUF 100 120 and SUF 100 150 models:
1.Follow the instructions for Initial Start Up on page 52 to connect manometers to the supply and manifold gas pressure taps and to start the water heater.
2.Remove the manifold gas pressure regulator cover screw, see Figure 57 on page 53.
3.Using a small flat tip screw driver turn the adjustment screw clockwise to increase manifold gas pressure and counter clockwise to decrease manifold gas pressure.
Note: Turn the manifold gas pressure adjustment screw in small increments (no more than 1/4 turn) and allow the manifold gas pressure to stabilize for several minutes before making further adjustments.
4.Replace the gas pressure regulator cover screw.
5.Cycle the burner on and off several times to check operation.
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