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Fix a water heater that has no hot water

We'll confirm no hot water, rule out power and pilot, then isolate the cause—pilot, elements, or thermostat—or tell you when to call a plumber.

Troubleshooting · Home plumbing
15–60 min
What you'll need
  • Multimeter (for electric—continuity tests)
  • Screwdriver set
  • Replacement heating elements (if tests show a fault)
Step 1 of 11

Quick triage — pick your path

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Choose the option that matches what you see. You can jump straight to that section.

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Steps

Goal: Confirm the symptom, rule out power and pilot, then isolate the cause.

  • Turn on hot water at multiple fixtures—kitchen, bathroom, shower. If no fixture gets hot water, the water heater has failed.
  • Good: No hot water anywhere—proceed to Gas path or Electric path based on your water heater type.
  • Bad: One fixture gets cold water—different issue; check that fixture. See When to get help.

Gas — Check pilot

Goal: Confirm the pilot is lit. If out, call a plumber—gas pilot work requires a professional.

  • Look through the sight glass at the bottom of the tank. The pilot light should be a small blue flame.
  • If it is out, call a plumber—gas pilot work requires a professional. Do not attempt to work on the pilot yourself.
  • Good: Pilot lit and stays lit—wait 30–60 minutes for the tank to heat.
  • Bad: Pilot will not stay lit when you release the button—thermocouple or gas valve. Call a plumber. Do not work on gas valves yourself.

Electric path

Goal: Check the breaker, heating elements, and thermostat.

  • Verify the circuit breaker for the water heater has not tripped. Reset if tripped and wait 30–60 minutes.
  • If the breaker is on and still no hot water, turn off power and test each heating element for continuity with a multimeter. Replace any that show no continuity.
  • Check both thermostats are set to 120°F or higher. Press the red reset button on the upper thermostat (high-limit thermostat) if it tripped.
  • Good: You found and fixed the fault. Wait 30–60 minutes for the tank to heat.
  • Bad: All parts test good but still no heat—call a plumber.

When to get help

If you smell gas, evacuate immediately. Do not turn on lights or appliances. Call 911 or your gas utility from outside.

Call a plumber if:

  • The pilot will not stay lit (thermocouple or gas valve).
  • You have replaced the heating elements and still no heat.
  • You are not comfortable with electrical or gas work.

Verification

  • Hot water flows at all fixtures after 30–60 minutes.
  • Pilot stays lit (gas) or breaker stays on (electric).
  • No gas smell or tripped breaker.

Escalation ladder

Work from the device outward. Stop when the problem is fixed.

  1. Confirm symptom Verify no hot water from any fixture—not just one faucet.
  2. Gas — Check pilot Check the pilot. If it is out, call a plumber. If it will not stay lit, thermocouple or gas valve—call a plumber.
  3. Electric — Breaker and elements Reset the breaker. Test heating elements for continuity. Replace if faulty.
  4. Check thermostat Confirm thermostat is set to 120°F or higher. Check high-limit reset on electric.
  5. Call a plumber Gas smell—evacuate, call 911 or gas utility from outside. Pilot will not stay lit, elements replaced but no heat—call a plumber.

What to capture if you need help

Before calling support or posting for help, have these ready. It speeds everything up.

  • Water heater type (gas or electric)
  • Whether the pilot is lit (gas)
  • Whether the breaker is on (electric)
  • Element test results (electric)
  • Steps already tried

Is there no hot water from any fixture?

Turn on hot water at multiple fixtures. If no fixture gets hot water, the water heater has failed.

Turn on hot water at the kitchen faucet, bathroom sink, and shower. Good: No hot water anywhere—water heater fault. Bad: One fixture gets cold water—different issue; check that fixture.

Yes No

You can change your answer later.

Is the water heater gas or electric?

Gas units have a gas line and pilot. Electric units have a power cord and no pilot.

Check the water heater. Gas: gas line and pilot light at bottom. Electric: power cord or conduit. Good: You know the type. Bad: Unsure—call a plumber.

Gas Electric

You can change your answer later.

Is the pilot light lit?

Look through the sight glass at the bottom of the tank. The pilot should be a small blue flame.

Check the pilot light. If out, call a plumber—gas pilot work requires a professional. Good: Pilot lit and stays lit—wait 30–60 min for hot water. Bad: Pilot will not stay lit—thermocouple or gas valve; call a plumber.

Yes No

You can change your answer later.

Wait for tank to heat

Wait 30–60 minutes for the tank to heat. You should see hot water at the fixtures. If still no hot water, the thermostat or gas valve may be faulty—call a plumber.

Done

Call a plumber

If the pilot is out, call a plumber—gas pilot work requires a professional. Do not attempt to work on the pilot yourself. If the pilot goes out when you release the button after a plumber has restored it, the thermocouple has failed—call a plumber. Do not work on gas valves yourself.

Done

Is the circuit breaker on?

Electric water heaters use 240 volts. Both legs must be on.

Check the circuit breaker for the water heater. Reset if tripped. Wait 30–60 minutes for the tank to heat. Good: Breaker on and hot water returns. Bad: Breaker keeps tripping or still no hot water—check elements.

Yes No (tripped)

You can change your answer later.

Reset breaker and wait

Reset the breaker. Wait 30–60 minutes. If it trips again, the element or thermostat may be shorted—call a plumber.

Done

Do the heating elements have continuity?

Turn off power. Test each element with a multimeter for continuity.

Turn off power at the breaker. Test each heating element for continuity. Replace any that show no continuity. If both test good, check the high-limit thermostat reset button.

Yes No

You can change your answer later.

Replace element and test

Replace the faulty heating element with a matching part. Restore power and wait 30–60 minutes. The water should heat.

Done

Is the thermostat set to 120°F or higher?

Check both upper and lower thermostats on electric.

Confirm thermostat is set to 120°F or higher. Press the red reset button on the upper thermostat if it tripped. Wait 30–60 minutes. If still no heat, call a plumber.

Done

Call a plumber

If you smell gas, evacuate immediately. Call 911 or your gas utility from outside. Call a plumber if: the pilot will not stay lit; you have replaced elements and still no heat; or you are not comfortable with electrical or gas work.

Done

Reviewed by Blackbox Atlas

Frequently asked questions

Why would a water heater have no hot water?
Gas heaters: pilot out, thermocouple, or gas valve. Electric heaters: tripped breaker, blown heating element, or faulty thermostat. Check power and pilot first, then the heating components.
Can I fix a water heater with no hot water myself?
Yes, for electric you can reset the breaker and test elements. For gas, if the pilot is out, call a plumber—gas pilot work requires a professional. Thermostat and gas valve work require a professional.
When should I call a plumber for no hot water?
If you smell gas, evacuate and call 911 or your gas utility from outside. Call a plumber if the pilot will not stay lit, if you have replaced elements and still no heat, or if you are not comfortable with electrical or gas work.

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