Faucet has no hot water while (other fixtures may have hot water)

Use only checks that match the exact appliance or system and its official guide.

1. Check 1

   With the faucet directed into the sink or tub, run the cold side briefly, then move the handle to hot without touching the heater; compare flow, temperature change and time to warm with a nearby fixture that has hot water.

   Expected result: Record whether hot has no flow, weak flow, normal flow but cold water, or water that becomes warm only after a longer wait. Note whether the nearby fixture remains hot.

   Next step: Continue to the local hot-valve and hose check when the symptom is limited to this faucet. If multiple fixtures are affected, stop local faucet disassembly and consult the water-heater manual or a qualified plumbing professional.

   Stop if: Do not increase the water-heater temperature, run a faucet unattended, or put hands under unexpectedly hot water while comparing outlets.

   Why this matters

   Why: Hot-only weak or absent flow suggests the local hot supply, valve or inlet is restricted. Normal flow that stays cold suggests a cartridge, balancing or thermostatic mixing problem. If all fixtures lose hot water, the local-faucet assumption no longer fits.

2. Check 2

   From under the sink or at the accessible faucet supply, visually inspect the hot shutoff valve and hot flexible line; if a normal hand-operated valve is clearly partly closed, open it gently according to its design, without forcing it.

   Expected result: Look for a valve turned off or partly open, a kinked or crushed hot hose, a leak, corrosion, a swollen hose, or a hot line not connected to the faucet's hot inlet. Compare hot and cold connections without disconnecting them.

   Next step: If a simple valve-position or hose-routing issue is confirmed and no leak is present, correct only what the fixture instructions permit and retest. If the valve will not move, leaks, or the line must be disconnected, shut off water safely and call a plumber.

   Stop if: Do not force a seized stop valve, use pliers on a fragile handle, disconnect a pressurized hose, or continue if water begins leaking under the cabinet.

   Why this matters

   Why: A closed valve or kink can remove hot flow at one faucet while other fixtures remain normal. A leaking, corroded or stuck valve needs replacement, and a recent installation with crossed connections can make the hot position deliver cold water.

3. Check 3

   If the faucet has a removable aerator or pull-out/pull-down spray head, use the exact faucet instructions to remove only that outlet piece, keep the hose from retracting, and briefly test flow into the sink; skip it if the part is fixed, seized or the model procedure is unknown.

   Expected result: Compare the stream with the aerator or spray head installed and removed. Look for mineral scale or debris and note whether hot flow is normal from the hose or spout with the end piece removed.

   Next step: Clean the removable outlet only with the manufacturer's approved method and reinstall it, then retest. If restriction remains upstream, stop and identify the faucet model before opening its valve or cartridge.

   Stop if: Do not poke jets with metal, lose a pull-out hose inside the faucet, use harsh chemicals, or remove a spray head while hot water is splashing.

   Why this matters

   Why: Normal hot flow with the outlet piece removed makes a clogged aerator or spray head likely. Poor hot flow even with it removed points toward the hot supply, inlet, cartridge or valve.

4. Check 4

   Identify the faucet type and model from its markings or documentation, then consult that model's instructions for a hot-side cartridge, pressure-balancing spool, thermostatic cartridge, inlet screen or rotational temperature limit; do not remove the valve by guesswork.

   Expected result: Determine whether it is a single-handle sink or lavatory faucet, two-handle faucet, tub/shower mixing valve or electronic faucet, and whether cold flow is normal while hot is absent or merely limited.

   Next step: Follow only the exact model procedure for accessible cleaning or cartridge service, with water isolated and hot surfaces avoided. If the valve is concealed, seized, behind a wall or requires specialized tools, arrange qualified plumbing service.

   Stop if: Do not substitute a cartridge by appearance, reverse a cartridge without model instructions, defeat an anti-scald limit, open a wall valve or leave the faucet partly disassembled with water available.

   Why this matters

   Why: A sink faucet may have a blocked or failed cartridge or valve body. A tub/shower unit may have debris in a balancing spool, closed check stops or a model-specific calibration. Electronic fixtures may have control or power behavior that cannot be inferred from a standard mechanical faucet.

5. Check 5

   Retest the faucet alongside a known-hot fixture, then check whether the water heater has a separate alarm, leak, pilot, power or diagnostic indication without opening panels or changing settings.

   Expected result: Record whether only the original faucet remains cold, whether other outlets have also become cold, whether water is too hot, and whether the heater shows a fault, leak or loss of power or fuel.

   Next step: Use the water-heater manual for model-specific user-level checks only. Have a qualified plumber or water-heater technician diagnose heating, gas, electrical, recirculation or concealed-piping faults.

   Stop if: Do not remove heater covers, test energized terminals, relight gas equipment outside its manual procedure, bypass safety controls or raise the setpoint to mask a faucet problem.

   Why this matters

   Why: A remaining one-faucet symptom supports a local valve, supply or faucet-body diagnosis. Loss of hot water at multiple fixtures shifts the fault upstream to the heater, recirculation or main hot-water piping. Excessively hot water is a scald condition.