CSLB C-36 Plumbing ContractorFixture and Appliance InstallationHard
A client reports intermittent low hot water pressure only at the kitchen sink, while all other hot and cold fixtures in the house have adequate pressure. The kitchen sink has a single-handle faucet. The plumber has verified that the main water pressure is good and the water heater outlet pressure is normal. What is the most likely cause of this isolated low hot water pressure issue?
- AA clogged or restricted hot water supply tube to the kitchen faucet.
- BA faulty pressure reducing valve (PRV) on the main water line.
- CA partially closed main shut-off valve.
- DSediment buildup in the aerator of the kitchen faucet.
Show answer & explanationAnswer & explanation
Correct answer: A. A clogged or restricted hot water supply tube to the kitchen faucet.
Since the problem is isolated to only the hot water at one fixture (the kitchen sink), and other hot and cold pressures are fine, the issue is most likely localized to the hot water supply path *to that specific faucet*. A clogged supply tube or a restriction within the faucet's hot water cartridge would cause this.
Why the other options are wrong
- B. A faulty PRV would affect the pressure of all water (hot and cold) throughout the entire house, not just isolated to one hot water tap.
- C. A partially closed main shut-off valve would affect all fixtures, hot and cold, which isn't the case here.
- D. Sediment in the aerator would affect both hot and cold water flow at the kitchen sink, not just the hot.
Isolated Low Hot Water Pressure
When low hot water pressure is observed at only one specific fixture, but not elsewhere in the plumbing system, it typically indicates a localized obstruction or malfunction within that fixture's hot water supply line or internal components.
- Problem is fixture-specific.
- Often due to sediment or faulty cartridge.
- Requires investigation at the point of use.
Memory trick: Isolated low flow? Check where the water doesn't go!