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Symptom
No hot water: common causes and what to check
The short answer
No hot water usually traces to a handful of causes. On a gas heater it is often a pilot light or gas-supply issue; on an electric heater it is often a tripped breaker or a failed heating element. If the water is warm but runs out fast, suspect a failing element, sediment in the tank, or a low thermostat setting rather than a complete failure. A few of these you can safely check yourself before calling anyone.
If you have a gas water heater
The usual suspect is the pilot light or the flame sensor, called a thermocouple. If the pilot is out, the unit’s label explains how to relight it; do that only if you are comfortable, and never if you smell gas. A thermocouple that keeps letting the pilot die is a common, inexpensive repair. Also confirm the gas supply to the home is on.
If you have an electric water heater
Start at the breaker panel, since a tripped breaker is the simplest fix. If the breaker is fine, the most common failure is a heating element, and most electric units have two. A failed upper element can leave you with no hot water; a failed lower element often leaves you with hot water that runs out quickly. Elements are a routine replacement.
What you can safely check
- Whether the water heater’s breaker has tripped, on an electric unit.
- Whether the pilot is lit and the gas is on, on a gas unit.
- Whether the temperature dial on the unit was accidentally turned down.
- Whether the problem is one fixture or the whole house, which helps narrow it down.
Leave anything involving opening the unit, testing elements, or gas components to a licensed plumber. If you ever smell gas, leave the home and call your gas utility.
Repair or replace
Most no-hot-water causes are affordable repairs. Replacement enters the picture when the unit is old, is also leaking, or keeps failing. See water heater replacement cost for the numbers, and if you also see water pooling, start with what a leaking water heater means.
Common questions
No hot water questions
Why do I suddenly have no hot water?
The most common causes are a pilot light or gas supply problem on a gas heater, or a tripped breaker or failed heating element on an electric heater. If the water is warm but runs out fast, the problem is usually a failing element or a thermostat rather than a total loss of heat.
What can I check myself before calling a plumber?
Safely, you can check a few things: whether an electric heater’s breaker has tripped, whether a gas heater’s pilot is lit and the gas is on, and whether the thermostat on the unit was bumped. Relight a pilot only if you are comfortable following the label instructions. If you smell gas, leave and call your gas utility.
Why does my hot water run out so quickly?
Hot water that runs out faster than it used to often points to a failing lower heating element in an electric unit, a buildup of sediment in the tank that shrinks its usable capacity, or a thermostat set too low. Flushing the tank or replacing an element can restore capacity in many cases.
Is no hot water a sign I need a new water heater?
Not necessarily. Many causes are inexpensive repairs, such as a heating element, thermostat, or thermocouple. But if the unit is old, is also leaking, or keeps failing, replacement may be the better value. Our repair-versus-replace guide helps you weigh it.
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Checked the basics and still no hot water?
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