Water Heater Not Heating? 7 Causes and What to Check First

Losing hot water is one of those problems that feels catastrophic and usually is not. In most homes we visit, the cause turns out to be one of a short list of failures — and two of them you can check yourself in under five minutes without tools.

Here is how we work through it, in the order that finds the problem fastest.

1. The pilot light or igniter (gas heaters)

On a gas water heater, no hot water at all most often means the burner is not lighting. Older units use a standing pilot light that can be blown out by a draft. Newer units use an electronic igniter that can fail outright.

If your unit has a pilot and it is out, the relight instructions are printed on the tank itself. If it lights and then goes out again within a minute or two, stop — that usually means a failing thermocouple, and relighting it repeatedly will not fix that.

2. A tripped breaker or reset button (electric heaters)

Electric water heaters have a high-limit reset — a red button behind the upper access panel. When the water overheats, that switch trips and cuts power to the elements. Pressing it restores heat.

The important part: a reset that trips once may be nothing. A reset that trips repeatedly is telling you something is wrong — usually a failed thermostat or a shorted element. Repeatedly pressing it is treating the alarm instead of the fire.

3. A burned-out heating element

Electric heaters have two elements. When the lower one fails, you get a small amount of hot water that runs cold fast. When the upper one fails, you typically get no hot water at all. That symptom split is genuinely useful for diagnosis.

Hard North Texas water accelerates this. Scale builds on the element, it overheats under its own insulation, and it burns out early. This is the single most common electric water heater failure we see.

4. Sediment in the bottom of the tank

Minerals settle out of the water and collect at the bottom of the tank. On a gas heater that sediment sits directly between the burner and the water, insulating it. The burner runs longer, the water gets less hot, and the tank bottom overheats.

The tell is sound: popping, rumbling, or crackling while the unit heats. That is water flashing to steam underneath the sediment layer. Annual flushing prevents it, and in our water it genuinely matters.

5. A failed thermostat

Both gas and electric units use a thermostat to control temperature. When it fails, you can get no heat, lukewarm water, or dangerously hot water. Any of those is a reason to have it checked.

We set thermostats to 120°F. That is hot enough to be comfortable and to control bacteria, but not so hot it becomes a scald risk — which matters in homes with kids or elderly family.

6. A dip tube that has broken

The dip tube carries incoming cold water to the bottom of the tank so it heats before rising. When it cracks or breaks, cold water dumps in at the top and mixes straight into the hot water heading to your taps.

The classic symptom is hot water that suddenly runs lukewarm much faster than it used to, with no other change. It mimics an undersized tank, which is why it gets misdiagnosed.

7. The heater is simply at end of life

In our water, a tank water heater realistically lasts 8 to 12 years. Past that, repairs start stacking up and the tank itself becomes the risk — because tank failure does not mean no hot water, it means water across your floor.

If yours is past 10 years and needs a significant repair, we will tell you honestly when replacement is the better spend. We would rather you hear that than pay for a repair on a tank that fails six months later.

What you can safely check yourself

1. Confirm the breaker for the water heater has not tripped.
2. On an electric unit, check the red high-limit reset behind the upper panel.
3. On a gas unit with a standing pilot, check whether the pilot is lit.
4. Listen while it heats — popping or rumbling points to sediment.
5. Note the age. There is a date code on the manufacturer label.

Beyond that, you are into elements, thermostats, gas components and water under pressure. That is where it stops being a homeowner job.

When to call right away

• You smell gas — leave first, then call.
• Water is pooling around the base of the tank.
• The reset button trips again after you press it.
• The relief valve is discharging.
• Hot water is scalding rather than merely hot.

We answer 24/7 and we are family-owned and local, so you get a real technician rather than a call center. If you are without hot water, call (469) 338-5533 and we will get you a straight answer on what failed and what it costs.