Why Is My Water Heater Not Heating?

If your water heater isn’t producing hot water, the issue is often easier to diagnose than you’d think. In most cases, it comes down to one of three things: a startup issue, a failed component, or a built-in safety control doing exactly what it’s designed to do.

If your water heater is giving you the cold shoulder, here’s what to do next.

First: Is This a New Installation or an Existing System?

Before getting into specifics, it helps to answer one simple question:

Is this a brand-new water heater, or an old one that just suddenly stopped working?

• If the heater was just installed and has never produced hot water, the issue is often related to missed startup steps, safety checks, or power or gas supply.
• If the heater worked before and suddenly stopped, the problem is more likely tied to a component failure or a safety shutoff.

Once you know which situation applies, the next steps become much clearer.

New Water Heater Not Heating?

A brand-new water heater not heating properly right after installation is frustrating, but it’s more common than most homeowners expect.

Before assuming the unit is defective, there are a few basic things you can safely check:

• Electric units: Make sure the breaker at the electrical panel is fully engaged and seated correctly. A breaker can appear “on” without actually supplying power.
• Gas units: Confirm the gas shutoff valve is fully open.
• Startup: Follow the manufacturer’s lighting or startup instructions exactly, especially on first use.

If those steps don’t restore hot water, it’s best to stop there. Modern water heaters come with safety controls that shut the system down if something isn’t right. Trying to bypass those controls can damage the unit, create safety risks, or void the manufacturer’s warranty.

Old Water Heater Not Heating?

When a hot water heater suddenly stops working, the issue usually involves one of a few core components.

Electric Water Heaters

If you have an electric water heater, common issues include:

• A failed heating element
• A tripped high-limit switch
• A thermostat that’s stopped regulating temperature properly

What to do: Start by confirming the breaker at the electrical panel is fully engaged and seated correctly. If the water heater has a visible reset button (often near the thermostat access panel), you can check whether it has tripped. If those steps don’t restore hot water, it’s best to stop there and speak with a water heater expert.

Gas Water Heaters

If you have a gas water heater, the issue often involves:

• The pilot light or thermocouple
• The gas control valve
• Safety shutoffs related to venting or combustion

What to do: If the pilot light is out, you can try relighting it by following the manufacturer’s instructions exactly. Make sure the gas shutoff valve is fully open and that nothing is blocking the vent or airflow around the unit.

If the pilot won’t stay lit, the heater shuts itself down repeatedly, or you notice unusual odors or soot, it’s time to call a plumber.

Preventative Care: Keeping Your Water Heater Healthy

Many water heater issues don’t come out of nowhere. Sediment buildup, worn components, and ventilation problems often develop gradually, especially on older systems. Regular maintenance helps catch minor issues early, improves efficiency, and can extend the life of your water heater.

Not sure where to start? This water heater maintenance guide will get you started.

Get Reliable Hot Water Back Now

If your hot water heater is not heating, Stephens Plumbing can help, whether it’s a new installation or an older system that suddenly stopped working.

We’ll identify the issue, explain your options clearly, and restore hot water without guesswork or unnecessary upsells. Contact us today!