Typically, the sound occurs for various reasons, including high pressure, low pressure, and failure of the auto shut-off valve after 5 years.
Reason 1:
If the incoming water pressure exceeds 75 psi, install a pressure reducer (Part #105229).
Reason 2:
If the incoming water pressure is below 50 psi, inspect the city water supply to the system membrane housing inlet. If it's below 50 psi, examine the pre-filters for possible clogging. If the pressure is adequate (above 50 psi), check the membrane; if it's over 2 years old, consider replacing it (Membrane Part #104092). If the city water pressure is still below 50 psi despite the above measures, a booster pump(Part #105715) is necessary to elevate the pressure to over 60 psi.
Reason 3:
Inspect the flow restrictor(part #105149) for partial blockage due to accumulated dirt from water flow, especially when pressure is applied from the opposite direction.
Reason 4:
If the auto shut-off valve exceeds 7 years in age, it's advisable to replace it. Search for item #105112 for the replacement.
