No Hot Water
Updated February 20, 2026
No hot water from any fixture? Cause depends on gas vs. electric. Common culprits: pilot light out, tripped breaker, failed element, faulty thermostat or gas valve.
Overview
Root cause is almost always inside the water heater. Gas and electric fail differently. Gas: pilot light, thermocouple, gas control valve. Electric: one or two heating elements controlled by thermostats. Many fixes you can troubleshoot yourself, but gas lines and 240-volt wiring should be left to a pro.
Symptoms
- No hot water from any fixture
- Lukewarm but never reaches full temperature
- Runs out much faster than usual -- failed lower element on electric heater
- Pilot light out and will not stay lit after relighting (gas)
- Breaker for the water heater keeps tripping (electric)
- Gas smell near the heater -- shut off gas and call your utility immediately
Common Causes
- Pilot light out (gas) -- drafts, dirty pilot orifice, or failing thermocouple. Will not stay lit after relighting? Thermocouple needs replacing.
- Tripped ECO reset button (electric) -- safety switch on the upper thermostat trips when temperature exceeds limits. Red button, press to reset. Repeated tripping means a deeper problem.
- Failed element (electric) -- upper element out means no hot water at all. Lower element out means some hot but runs out fast. Burns out from sediment, age, or dry firing.
- Faulty gas valve or thermostat -- gas valve fails and the burner will not ignite even with a working pilot. Electric thermostat fails and the element never gets the signal to heat.
- Tripped breaker (electric) -- short in the element, water in the wiring compartment, or overloaded circuit. Reset, but if it trips again immediately, stop and call a pro.
- Sediment buildup -- insulates water from the burner (gas) or buries the lower element (electric). Reduces heating capacity over time.
What You'll Need
How to Fix It
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Determine Your Water Heater Type
Gas or electric? Gas: gas line connected, vent pipe on top. Electric: no vent, dedicated breaker (usually double-pole 30-amp). Diagnostic path is different for each.
Tip: Rating plate on the heater has model number, fuel type, and age. Over 10-12 years old and failing? Replacement may be more cost-effective than repair. -
Gas Heater: Check and Relight the Pilot Light
Access panel at the bottom. Pilot out? Follow the instructions on the unit. Typically: gas knob to Pilot, press and hold, igniter or long lighter, hold 30-60 seconds, release. Stays lit? Turn to your temperature setting. Goes out immediately? Thermocouple is bad.
Warning: Strong gas smell when you open the panel? Do not light anything. Leave the house. Call your gas utility. Do not return until cleared. -
Gas Heater: Inspect the Thermocouple and Gas Valve
Thermocouple is the copper tube in the pilot flame. Tells the gas valve the pilot is lit. Corroded, bent away from flame, or broken? Gas valve will not open. Try bending the tip closer to the flame. Does not help? Replace ($10-15, hardware store). Thermocouple fine but burner still will not fire? Gas control valve may need replacement -- that is a plumber job.
Tip: Bring the old thermocouple to match length and connector. Most are universal, but some brands (Honeywell, White-Rodgers) use proprietary connectors. -
Electric Heater: Check the Breaker and Reset Button
Electrical panel: water heater breaker tripped? Flip fully off, then on. At the heater: upper access panel off (two screws), pull back insulation. Red reset button (ECO) on the upper thermostat -- press firmly until it clicks. Panel back on, power on, wait 1-2 hours.
Warning: Breaker off before touching anything inside the panel. 240 volts is lethal. Non-contact voltage tester to confirm power is off before proceeding. -
Electric Heater: Test the Heating Elements
Reset did not work? Elements may be burned out. Breaker OFF. Both access panels off, disconnect wires from each element. Multimeter on ohms: probes on the two terminal screws. Working element reads 10-16 ohms. Infinite resistance (OL)? Burned out, needs replacement. Check both upper and lower.
Tip: Elements are $10-25. Element wrench (large socket) to remove. Drain the tank below the element level before removing to avoid flooding. -
Check for Sediment Buildup
Some hot water but not enough? Popping or rumbling? Sediment. Garden hose on the drain valve, run to a floor drain or outside. Let it run until clear. Drain valve clogs? Open and close a few times, or use a screwdriver to break up deposits. Annual flushing prevents this.
Tip: Heavy rust or sand-colored sediment? Glass lining may be deteriorating. Over 10 years old? Tank is nearing end of life.
When to Call a Pro
Call a plumber if you smell gas, if the breaker keeps tripping, if you are not comfortable with gas lines or 240-volt wiring, if the gas control valve needs replacing, if the tank is leaking from the bottom, or if you have a tankless/heat pump/hybrid unit. Gas and high-voltage work is not worth the safety risk for most homeowners.
Prevention Tips
- Flush annually. Single most effective maintenance for extending tank life.
- Professional inspection every 2-3 years. Anode rod, gas connections, venting, overall condition.
- Anode rod every 3-5 years. Protects the tank from internal corrosion.
- Thermostat at 120 degrees. Recommended for safety, efficiency, and adequate hot water.
- Gas heater: clear area of flammable materials, proper ventilation for combustion air.
- Electric heater: dedicated surge protector on the circuit protects thermostat and elements.