No Hot Water: What to Check First

When there is no hot water anywhere in the house, start with the simple things: power to the heater, fuel to the heater, and whether the problem is the whole house or one tap. Most of the time the cause is a tripped breaker, a failed heating part or a gas supply problem, and a few safe checks will tell you which way it points. If those checks do not bring the heat back, One Call Home Pros connects you with a vetted, licensed, insured local professional who works on water heaters every day.

The short answer

If the whole house has gone cold at once, the heater itself has stopped heating. On an electric tank, that usually means the breaker has tripped, a heating element has failed, or the high-limit safety switch has cut the power. On a gas tank, the pilot or burner is usually out, or the gas supply is off. On a tankless unit, the display often shows an error code that points at the cause.

If only one tap or shower runs cold while the others are hot, the heater is probably fine. The fault is more likely in that fixture’s mixing valve or cartridge, which is a plumbing job rather than a water heater one.

Lukewarm water is a different symptom from none at all. Warm but not hot often means one of the two elements in an electric tank has failed, or the tank is full of sediment.

What to check first

These checks are safe for a homeowner and take a few minutes. Stop at any point where something looks wrong.

1. Run hot water at a second tap, in another room. If it is hot there, the problem is the first fixture, not the heater.
2. For an electric heater, look at the breaker panel. If the water heater breaker has tripped, switch it fully off and then on once. Do not reset it a second time.
3. For a gas heater, look through the small viewing window near the bottom of the tank, if it has one, to see whether a flame is lit. Do not take off covers or adjust the gas controls.
4. Check that the cold water supply valve on top of the heater is open. A closed supply valve can leave you with no hot water at every tap.
5. For a tankless unit, read the display. Write down any error code exactly as shown, and check that the unit’s power switch or plug has not been knocked off.
6. Look around the base of the heater for water. A heater that is cold and leaking needs a pro, not more checks.

When to stop and call a pro

Some parts of a water heater are not for homeowners. Electric heaters run on high voltage behind their access panels, and the reset button for the high-limit switch sits behind one of those panels. Leave the panels on. Gas heaters carry a fuel line, a gas valve and a vent that carries combustion gases out of the house. Leave all of them alone.

Stop and call if any of these is true:

• The breaker trips again after one reset
• You smell gas. Leave the house first, then call your gas utility or 911 from outside
• The pilot will not stay lit, or you are not sure how the gas controls work
• There is water on the floor around the tank
• You hear popping, hissing or a crackle that was not there before
• The tankless display shows the same error code after a restart

Tank or tankless: what each usually means

Electric tank. An electric tank heats with two elements, an upper and a lower, each with its own thermostat. If the upper element fails, the tank stops heating altogether. If the lower one fails, you get a short burst of warm water and then cold. The high-limit switch trips when the water gets too hot, which itself points at a thermostat fault. A licensed pro tests the elements and thermostats with the power off and replaces the failed part.

Gas tank. A gas tank relies on a pilot or an electronic igniter, a burner and a sensor that proves the flame is lit. When the sensor wears out, the gas valve shuts off as a safety measure and the water goes cold. A blocked vent or a lack of combustion air can also shut a heater down.

Tankless. A tankless heater only fires when water flows fast enough to trigger it. Mineral scale inside the heat exchanger, a dirty inlet filter, an ignition fault or a power problem can each stop it. The error code is the best clue you can give the pro.

Florida specifics worth knowing

Many South Florida homes have an electric tank heater in the garage or a utility closet. A garage that runs hot for much of the year does not stop a heater working, but it does make a cold one easy to overlook until the morning shower.

Broward County’s water carries minerals that settle as scale. In a tank, that scale collects at the bottom as sediment, which insulates the water from the lower element or burner and can cause rumbling. In a tankless unit, scale builds up inside the heat exchanger. Regular flushing slows both, and the pro can tell you whether it is due.

How One Call fits in

One Call Home Pros is a connector, not a plumbing or gas company. You tell us what the heater is doing, what kind it is and what you have already checked. We match you with a vetted local professional who holds the licence for the work and carries insurance. The pro finds the fault, explains it and makes the repair. One Call arranges the visit and stays with the job until it is done.

You pay One Call for the job, and One Call pays the pro. Ask what the price covers before any work starts. If the pro recommends a new heater rather than a repair, financing is available; ask about it when you call. You can read more about water heater repair and replacement, or see the pages for water heater repair in Margate, Tamarac and Pembroke Pines.

What the pro looks at

A pro called out for no hot water will usually check:

• Power at the heater, and whether the elements and thermostats test good
• The pilot, igniter, flame sensor and gas valve on a gas unit
• The venting, for blockage or poor draft
• Sediment in the tank, or scale and the inlet filter on a tankless unit
• The age and condition of the tank, including any rust or weeping at the base

If the tank is old and corroded, the pro may say a repair is not worth doing. That decision is yours, with the facts in front of you.

Get the hot water back

If the safe checks have not solved it and there is still no hot water, tell One Call what the heater is doing and what kind it is. We take it from there and match you with a vetted, licensed local pro.