CSLB C-36 Plumbing ContractorFixture and Appliance InstallationMedium
A plumber is troubleshooting an issue with low hot water pressure isolated to a single fixture (e.g., kitchen sink) in a residential home. All other hot and cold fixtures in the house have normal pressure. What is the MOST likely cause of this specific problem?
- AA malfunctioning water heater element.
- BA failing pressure reducing valve (PRV) for the entire house.
- CA clogged main water filter at the point of entry.
- DSediment buildup or a partially closed stopcock in the affected fixture's supply line.
Show answer & explanationAnswer & explanation
Correct answer: D. Sediment buildup or a partially closed stopcock in the affected fixture's supply line.
If low hot water pressure is isolated to one fixture, the problem is almost certainly within that fixture's hot water supply system. Sediment buildup in the aerator, a partially closed stopcock, or a kinked supply line specific to that fixture are common culprits.
Why the other options are wrong
- A. A malfunctioning water heater element affects water temperature, not pressure, and would typically affect all hot water fixtures, not just one.
- B. A failing house PRV would affect pressure at all fixtures, both hot and cold, throughout the entire house.
- C. A clogged main water filter would affect pressure at all fixtures, hot and cold, throughout the entire house.
Isolated Low Hot Water Pressure
A plumbing issue where low hot water pressure is observed at only one specific fixture, while other fixtures have normal hot and cold water pressure.
- Indicates a problem within that specific fixture's supply.
- Common causes include clogged aerators, partially closed stopcocks, or kinked supply lines.
- Does not typically involve the main water supply or water heater.
Memory trick: One tap's low flow, points to its own woe.