Why Do I Have No Hot Water and How Do I Fix It?

Root cause

A pilot light can go out from a passing draft, a brief interruption in gas supply, or simple normal wear over time, cutting off the flame that heats the tank entirely.

30-second check

Look through the small viewing window at the bottom of the tank for a blue flame. No flame confirms this cause.

Tools & materials

None beyond your hands — follow the instructions printed directly on your unit.

Step-by-step

1. 1 Confirm the gas valve is turned fully to 'On' — it can get bumped closed accidentally.
2. 2 Locate the pilot relighting instructions printed on the water heater's label.
3. 3 Follow those steps exactly, typically holding down a control knob while igniting the pilot with a built-in igniter or a long lighter.
4. 4 Hold the knob as instructed (often 30–60 seconds) to let the thermocouple heat up before releasing.
5. 5 Confirm the pilot stays lit after releasing, then wait for the tank to reheat (can take one to two hours for a full tank).

Root cause

Electric water heaters draw significant power, and a tripped breaker — from a power surge or overload — cuts electricity to the heating elements entirely, with no pilot light involved.

30-second check

Go to your breaker panel and look for the water heater's breaker in the off or tripped position.

Tools & materials

None required.

Step-by-step

1. 1 Locate the water heater's breaker in your panel.
2. 2 Switch it fully off, then back on.
3. 3 Wait one to two hours for the tank to reheat a full load of water.
4. 4 If the breaker trips again immediately, stop here — that points to Cause 4, not a simple overload.

Root cause

The thermocouple is a small safety sensor that detects the pilot flame and keeps the gas valve open as long as it senses heat. As it wears out, it fails to hold the valve open, causing the pilot to go out repeatedly even when relit correctly.

30-second check

You've relit the pilot correctly following the label instructions, but it won't stay lit for more than a few seconds to a minute after you release the control knob.

Tools & materials

Adjustable wrench, replacement thermocouple matching your model (inexpensive) — this involves gas-line components.

Step-by-step

1. 1 Turn off the gas supply to the unit completely.
2. 2 Disconnect the old thermocouple from the gas control valve and its mounting bracket.
3. 3 Install the new thermocouple in the same position and reconnect it to the valve.
4. 4 Restore gas supply and follow the pilot relighting instructions.
5. 5 Confirm the pilot stays lit reliably after a few minutes.

Root cause

If the pilot won't stay lit even after a new thermocouple, or if you notice any smell of gas at any point, the gas control valve itself — which regulates gas flow to the burner — may be the underlying issue, or there may be an active gas safety concern.

30-second check

Any smell of gas at all, or a pilot that won't stay lit after replacing the thermocouple, means stop and call a professional (and, for gas smell, the utility first).

What a professional actually does

If gas is smelled, first ensures the area is safe and gas supply is shut off at the meter if needed; diagnoses whether the control valve, venting, or another component is at fault using proper testing equipment; replaces the gas control valve as a complete unit (these aren't typically repaired piecemeal); and verifies safe operation and proper venting before leaving.