When your water heater stops working, it affects your whole day. No hot water for showers, dishes, or laundry makes it a problem that can’t wait. Not to worry! We’re here to help. Fortunately, most water heater issues come down to a handful of common causes, and knowing what to look for can help you figure out your next step quickly.
In this guide, we’ll walk you through how to troubleshoot your water heater, explain the 10 most likely reasons why your water heater stopped working, and help you decide whether it’s a quick fix or time to call a technician. We’ll also give you some tips for maintaining your water heater so that you can avoid these problems in the future.
Before You Start: How to Troubleshoot a Water Heater Safely
Before you start poking around your water heater, take a few basic safety steps. These apply whether you have a gas or electric unit.
Safety Precautions
Electric water heaters are high-voltage appliances and gas-powered appliances need to be inspected with care. So before you do anything, it’s important to take some safety precautions.
For electric water heaters: First, shut off the power to your water heater. Flip the breaker switch for the water heater in your electrical panel. If you ever need to touch wiring, use a voltage tester first.
For gas water heaters: Turn off the gas supply at the valve before inspecting anything.
Once the power or gas is off, open the cold water supply valve to relieve any built-up pressure. Then crack open the drain valve at the bottom of the tank and let a small amount of water out. This will help prevent any scalding if there is hot water in the tank.
Once you’ve taken these safety precautions, you can start troubleshooting your water heater.
Related: Gas vs. Electric Water Heaters – Which Should You Choose?
Check Your Warranty
If your water heater is relatively new, it may still be covered under the manufacturer’s warranty. Check your sales receipt or the manufacturer’s website. Warranties typically cover parts for a set number of years, though normal wear and tear is usually excluded. If you need to call the manufacturer, find the rating plate on the water heater which holds important information such as model, serial number, manufacturing year, and more.
What Are the Warning Signs a Water Heater Is Going Bad?
Water heaters usually give some warnings that they are on their last legs. Watch for these signs:
- Little or no hot water
- Water temperature that fluctuates unexpectedly
- Visible leaking around the tank
- Reduced water flow
- Banging, popping, or rumbling sounds
- Discolored or foul-smelling hot water
Don’t ignore these signs or wait until you have no hot water at all. Catching a problem early can mean the difference between a simple repair and a full replacement. When in doubt, call a professional and get your water heater assessed before it goes out or causes damage to your home.
Related: 10 Noticeable Signs Your Water Heater Is Going Bad
Why Is My Water Heater Not Turning On?
If your water heater won’t turn on at all, start with the basics before assuming the worst.
Check The Power Supply (Electric Water Heaters)
For electric water heaters, head to your circuit breaker panel. A tripped breaker is one of the most common, and easily overlooked, reasons a water heater suddenly stops working. Reset the breaker and see if the unit comes back on. If it trips again, that points to a deeper electrical issue that a technician should look at.
Check the Pilot Light (Gas Water Heaters)
Gas water heaters rely on a pilot light to ignite the burner when hot water is needed. If the pilot light has gone out, the heater simply won’t fire and you’ll need to relight it. Most units have relight instructions printed directly on the heater. If yours requires manual ignition, you’ll find the steps in your owner’s manual or on the manufacturer’s website.
Related: Why Does Your Water Heater Pilot Light Keep Going Out?
Why is My Hot Water Heater Not Heating Water?
Getting water out of your taps, but it’s cold or barely warm? That’s a different problem than a heater that won’t turn on, and often points to one of these causes.
Check the Thermostat Setting
The U.S. Department of Energy recommends setting your water heater thermostat to 120°F for most households. Settings below that can produce lukewarm water, while settings that are too high increase energy use and the risk of scalding. If the thermostat is set correctly but the water still isn’t heating, the thermostat itself may be faulty and need replacing.
Test Your Water
Brown or discolored water coming from your hot taps usually indicates sediment buildup or corrosion inside the tank, and not a thermostat issue. Cold water, on the other hand, typically points back to the power, pilot light, or heating element problems covered above.
10 Reasons Your Water Heater Is Not Working
If you have ruled out the issues we have already covered and you are still not getting any hot water, there are a few more potential causes to investigate. Below are the most likely causes.
1. Water Leaks
A leak is one of the most common reasons why a water heater is not working. Check all around your water heater for any signs of water. If you see water, it could be coming from one of these three places:
- The drain valve
- The pressure relief valve
- The tank itself
If you spot a leak, turn off the power or gas to the unit immediately and call a plumber or technician. Don’t try to repair a leaking tank on your own.
Related: Why Is My Hot Water Heater Leaking Water?
2. Gas Leaks & Faulty Gas Valves
If your water heater is gas powered, a gas leak may be the reason why it’s not working. If you smell gas, turn off the power to the unit and call your gas company immediately. Another possibility is that the gas valve on the water heater is faulty and needs to be replaced. Do not try to repair a gas leak or faulty gas valve yourself. This is a job for a licensed technician.
3. Faulty Heating Element
Electric water heaters use one or two heating elements to warm the water inside the tank. When one fails, you may get lukewarm water. When both fail, you get nothing at all. If you have a digital multimeter, you can test the element’s resistance following your owner’s manual. If it doesn’t return a reading your heating element is faulty and the heating element needs to be replaced. If you aren’t comfortable testing your water heater’s heating element then call a qualified technician.
4. Faulty Temperature Pressure Valve
As water heats up in a water heater it expands. The temperature pressure valve releases water from the tank when the pressure gets too high. If this valve is not working properly and doesn’t release pressure when the correct temperature is reached, it can cause the water heater to stop working. If you notice dampness under the discharge line, first turn down the temperature of your water heater. If the dampness is still there, call a qualified professional to fix the faulty temperature pressure valve.
5. Rust & Corrosion
Corrosion builds up slowly inside the tank over time and can go unnoticed until it causes a leak or discolored water. Rusty-looking water coming from your hot taps is a clear signal that something isn’t right inside the tank. At that stage, it’s best to have a technician assess whether a repair is possible or if replacement is the smarter call.
6. Failing Anode Rod
The anode rod is a metal rod inside the tank that attracts corrosive minerals so the tank walls don’t corrode instead. It’s designed to wear down over time and once it’s depleted, the tank becomes vulnerable to rust and it needs to be replaced. Replacing the anode rod every few years is one of the best ways to extend your water heater’s life. If yours has never been replaced, it may already be gone.
7. Thermostat Control Issues
The water heater thermostat plays an important role in keeping your water heater at the right temperature. If the water heater thermostat is not set to the correct temperature, or if it’s failed, the water may be too hot or too cold. This is a relatively straightforward repair when caught early.
8. An Improperly Sized Water Heater
Sometimes the reason why a water heater isn’t working isn’t a malfunction, but instead its capacity. If you’re regularly running out of hot water during peak usage times (multiple showers, laundry, and dishwashing all happening at once), your unit may simply be too small for your household’s needs. An undersized heater will struggle to keep up and can make it feel like the system is failing when it’s actually just maxed out.
In this case, a repair won’t solve the problem and you’ll need to upgrade to a bigger water heater.
9. Damaged Burner Assembly or Gas Control
In a gas water heater, the burner assembly does the same job that a heating element does in an electric unit. It includes several components: the thermocouple, gas supply tube, pilot burner, and more. If any one of these parts is clogged or fails, the whole system goes down. Over time, normal wear and tear will eventually catch up with all of these parts.
10. Age
Most traditional tank water heaters last between 6 and 15 years. Tankless models can last 15 to 25 years or more with proper maintenance. If your unit is past the 10-year mark and you’re dealing with recurring issues, age is likely working against you. Continued repairs on an older unit often end up costing more than a replacement over time.
Additional reading: When to Replace Your Water Heater
How to Avoid Future Problems: Regular Maintenance Tips
A little routine maintenance goes a long way. Here’s what we recommend:
- Flush the tank once a year to clear out sediment that accumulates at the bottom. Sediment buildup makes your heater work harder and shortens its lifespan.
- Check the anode rod annually and replace it when it’s more than 50% depleted. This one step can add years to your water heater’s life.
- Set the thermostat to 120°F to balance comfort, energy efficiency, and safety.
- Schedule a professional inspection every year or two, especially once your unit is over 7 years old.
If you’d rather not keep track of all of this yourself, our maintenance agreement plans take care of it for you.
Frequently Asked Questions About Water Heater Problems
Why is my water heater not turning on?
The most common reasons a water heater won’t turn on are a tripped circuit breaker (electric units), an extinguished pilot light (gas units), or a failed igniter. Start by checking your breaker panel or pilot light before assuming a more serious problem. If neither of those is the issue, it could be a faulty thermostat, a failed heating element, or a gas supply problem. A qualified technician can quickly diagnose what the issue is.
Why is my hot water heater not heating water?
If your water heater is running but not producing hot water, the most likely culprits are a failed heating element (electric), a faulty thermostat, or sediment buildup that’s insulating the water from the heat source. On a gas unit, a dirty or failing burner assembly can also prevent proper heating. Check that your thermostat is set to at least 120°F first, then call for service if the problem continues.
What are the most common reasons a water heater stops working?
The most frequent causes we see are:
- Tripped breaker or extinguished pilot light
- Failed heating element (electric units)
- Faulty thermostat
- Sediment and mineral buildup inside the tank
- A worn-out or depleted anode rod
- Leaking from the tank, drain valve, or pressure relief valve
- Age-related wear on key components
How do I troubleshoot a water heater?
Start with safety: turn off the power or gas supply before inspecting anything. Then work through these steps:
- Check the circuit breaker or pilot light.
- Confirm the thermostat is set correctly (120°F is a good starting point).
- Look for any visible leaks around the tank and valves.
- Check the color and smell of your hot water. Discoloration suggests internal corrosion.
- Listen for unusual sounds like banging or rumbling, which can indicate sediment buildup.
If you’ve worked through these steps and still don’t have hot water, it’s time to call a technician.
What should I do if my water heater is not working?
First, rule out anything simple: check the breaker, the pilot light, and the thermostat setting. If you smell gas, leave the area immediately and call your gas company. If you see water pooling around the unit, turn off the power or gas and don’t use it until a technician has assessed it. For any issue you’re not comfortable diagnosing yourself, calling a professional is always the right call since attempting repairs on gas lines or high-voltage electrical components isn’t worth the risk.
How long should a water heater last?
Most traditional tank water heaters last 6 to 15 years. Tankless models, with proper maintenance, can last 15 to 25 years or more. If your unit is older than 10 years and showing signs of trouble, it may be more cost-effective to replace it than to keep repairing it. Our technicians can help you evaluate whether a repair or replacement makes more sense for your situation.
Can I repair my water heater myself?
Some minor things, like relighting a pilot light or resetting a tripped breaker, are reasonable DIY tasks. But most water heater repairs, especially anything involving gas lines, electrical components, or the tank itself, are best left to a licensed technician. Water heaters are high-voltage (or high-pressure gas) appliances, and mistakes can be dangerous or cause more expensive damage.
Water Heater Inspection and Replacement Services in Portland
There are many factors that go into deciding when to replace your water heater and Jacobs Heating & Air Conditioning experts are here to guide you. We carry a variety of hot water heaters so that your home or business has the best and most efficient water heaters around.
Avoid extra costs and fewer repairs by scheduling a maintenance check for your existing water heating system before issues arise. No matter what you need, we’re always just a phone call away.
Whether you are in the market for a new water heater or simply have questions about your current one, Jacobs Heating & Air Conditioning is here to help. As a family-owned company that’s been serving the Portland area for over 70 years, our technicians have seen just about every water heater issue there is. Give us a call today!
