CSLB C-36 Plumbing ContractorService, Repair, and MaintenanceHard
A client reports that their kitchen sink's hot water faucet has significantly reduced flow compared to the cold water faucet, and the cold water flow is normal. This issue is specific to the hot water side of this one faucet. What is the most likely cause?
- AA malfunctioning pressure reducing valve (PRV).
- BA blockage in the main hot water supply line to the house.
- CA restricted hot water supply tube or a faulty hot water cartridge/stem in the faucet.
- DA clogged aerator on the faucet spout.
Show answer & explanationAnswer & explanation
Correct answer: C. A restricted hot water supply tube or a faulty hot water cartridge/stem in the faucet.
Since the issue is specific to the hot water side of only one faucet, the problem lies within that faucet's hot water supply path, either the flexible supply tube connecting it to the wall, or the internal hot water cartridge/stem which controls flow within the faucet body. Mineral buildup or debris often causes such restrictions.
Why the other options are wrong
- A. A malfunctioning PRV would affect overall water pressure to the house, impacting both hot and cold water flows, or all faucets, not just one side of one faucet.
- B. A blockage in the main hot water supply line would affect ALL hot water faucets in the house, not just one.
- D. A clogged aerator would affect both hot and cold water flow from that specific faucet equally.
Single Faucet Hot Water Flow Issue
Diagnosis of reduced hot water flow at a single faucet, while other faucets and cold water flow are normal, indicating a localized problem.
- Issue isolated to one faucet's hot side
- Cold water flow is normal
- Common causes: supply tube, cartridge/stem, valve
- Mineral buildup is a frequent culprit
Memory trick: One faucet, hot water low? Cartridge or tube, that's the flow!