Troubleshooting Pilot Light Is On But No Hot Water (Step-by-Step)   

Few things are more frustrating than when your water heater is not producing hot water, with the possible exception of when the pilot light is on, but you still have no hot water. Before you take a sledgehammer to your water heater for some percussive maintenance, there are a few things you can check that may fix the issue.

Problems such as gas leaks, broken pilots, faulty gas valves, and broken thermometers can stop your water heater from working correctly. This can happen even when the pilot light appears to be on. Fortunately, many of these issues can be fixed using your household tools and a few safety precautions. 

Water heaters last between six to thirteen years. If you are experiencing issues inside this window, your water heater may simply be going through the first stages of aging. But before you go on replacing your water heater, it is worth going over some of the common problems to see if you can squeeze out a few more miles from your water heater.

What is the Pilot Light?

The pilot light is the flame on any gas appliance that ignites the gas supplied to it so that your appliance can provide heat. On your water heater, they are usually located on the underside of your tank and may have an access cover. If you aren’t sure where it is, you can check online for your particular make and model or your owner’s manual.

The pilot light is usually always on unless there is an issue with it. It is blue in appearance – if it is another color, either it is burning dirty or it is not at the right temperature. A greenish tint to the flame means that it is dirty, whereas a yellow tint means that it isn’t hot enough.

Pilot Light
Pilot Light

In the event that the pilot light does go out, it must be relit. There is a button that opens the valve to release gas. Light the pilot, but keep the button depressed for about another thirty seconds before you let go.  

That being said, newer models tend to use electric ignition. If you do not see a pilot light, check to make sure that your make and model has a pilot light in the first place.

Common Reasons There is No Hot Water 

The bad news is that there is no one particular reason that your water isn’t hot.  You may have to go down the checklist to find the source of the problem. The good news is that the more common list of reasons is fairly short, and some of the issues can be fixed with just a little bit of effort. 

You Have a Gas Leak 

The lack of gas means that there is not enough fuel inside the hot water heater to burn, which means that there is no heat being generated. However, if gas is leaking, there is a bigger problem than no hot water.  

A gas leak can be detected by a loud hiss or the smell of rotten eggs – if there is a leak, it should be addressed immediately.  Since the gas is combustible, too much gas in the air can create a fire hazard. Don’t use your phone, switch off household appliances in the area, and shut off the gas until the problem is addressed.

The Pilot is Broken

Just because the pilot light is on does not mean that it is working correctly. A ‘broken’ pilot may be burning, but it may not be blue, and it may not be steady. 

A flickering pilot light can mean that there is a lot of buildup, either of soot or dirt or some other contamination. Another sign of buildup is a yellowish flame, which means that the flame is not getting enough oxygen. 

Broken  Pilot

Another related issue is not with the pilot light but with the thermocouple, or the ‘flame sensor’ that keeps the gas valve open. If there is a problem with the thermocouple, however, your pilot light will not stay lit.

Faulty Gas Valve 

If your water heater is not getting a supply of gas, it cannot heat the water. If there are no leaks, then the problem may be with the gas valve.

First, make sure that the gas is on and the gas valve is in the correct position.  This may seem obvious, but nothing is more embarrassing than calling out a professional only to have them throw a switch to fix the issue.

Gas Valve

If the problem is not a leak, then check the pilot. If it is flickering, then there may be a gas flow restriction caused by a faulty gas valve.

Blown Fuse 

Some older houses have fuse boxes with individual circuits protected by fuses. In the event of overloads, short circuits, or grounding issues, the fuse blows and all electrical activity on that circuit stops. It could also be the reason your pilot light keeps going out.

Your water heater is on a dedicated circuit. You may be surprised to know that this is true even if you have a gas heater.  This is because the water heater will pull energy to assist it. 

Blown Fuse 

If the fuse goes out, it means that there was a short circuit or overload in the water heater. If this is the case, a careful investigation of the wiring should be made to track down the problem before replacing the fuse.

Your Circuit Breaker is Tripped 

Newer homes do not use fuse boxes, as these have largely been replaced by circuit breakers. The main difference between fuses and breakers is that where you can only use fuses once, a circuit breaker is a switch that you can use again and again.

Circuit Breaker

The two operate on the same principle, however. If the circuit ‘trips’, it is opening the circuit so that electricity ceases to flow.  

You can flip the switch so that electricity flow resumes. If it trips again, it means that there is an electrical short somewhere in the circuit that needs to be fixed.

Your Thermostat is Broken

If the thermostat is not regulating your water correctly, it means that it is broken. As a result, the water will be too hot (which will end up causing a short circuit in your system) or it will not heat the water at all.  

Thermostats are usually set between 120 to 140 degrees Fahrenheit. If your settings are correct but you do not have hot water, it means that the thermostat may be broken.

Broken Thermostat

The thermostat may be fixed by draining out sediment that has entered your water tank or by resetting the high-temperature cutoff switch. If neither of these things works, your thermostat will need to be replaced.

Best Fixes For a Water Heater With No Hot Water 

If the problems that we just went over seem a bit daunting, don’t worry, there are fairly straightforward fixes to these issues. The good news is that you can DIY most of these repairs using not much more than your household tools. Let’s go over some of these fixes to get you where you need to go. 

Replace the Heating Element

Replacing the heating element(s) will require you to drain your water heater.  Turn off your power at the breaker and drain away all the water 

The heating elements may or may not require specialized tools to get them out.  If you have a socket wrench, this is most likely what you will need.  

Replace the Heating Element

You will need to separate out the wires from the old heating element and replace them in the same way on the new heating element. Once you secure the new one, refill the tank with water. When the tank is refilled, check it for leaks and turn it back on.  

Replace the Breaker

A broken fuse makes for a simple DIY project, but make sure that you are wearing safety glasses and handling the equipment carefully. You will require a flashlight, a screwdriver, and a replacement breaker. Make sure that the replacement breaker is the exact same make and model as the old breaker.

Turn off the breaker’s main power, then remove the cover plate for the breaker you are trying to fix. Disconnect the wires, then reconnect them to the new breaker.  

Replacing Breaker

Put the cover back on and seal it up.  Finally, turn the power back on and test to make sure that the circuit is working.

Replace the Thermostat

If you are removing the thermostat, make sure that the power is off. Take a picture of the wiring before disconnecting anything – it’s very easy to get the wiring mixed up. 

Undo the wires, and replace the old thermostat with the new one. The wires must go in the exact same place.

Replacing Thermostat

Finally, make sure your thermostat is set correctly. If you have two thermostats, the bottom one should be set to 110 degrees Fahrenheit, and the upper one to 120 degrees. It is a good idea to check the thermostat that you did not replace to make sure that they are both at the right temperature.

Stop Any Leaks

Check the fittings between the pipes entering the water heater, the drain valve, and the pressure relief valve. If the fittings are leaking, tighten them with a wrench (if you have copper pipes, this will have to be done by a professional). If your drain valve is leaking, it must be replaced.

The pressure release valve may be leaking because of the heat of the water or pressure. Make sure that your temperatures are set up correctly, and check the pressure of your cold water. The PSI should be around the 80s, but if it is above 100 degrees, then you will need to contact your water authority to reduce your pressure.

Replace Your Pilot Light

Make sure that your gas is off, both at the gas control valve and the shutoff valve. Next, you will use an adjustable wrench to take out the ignitor, the thermocouple, the pilot tube, and the gas burner supply.  Take the screws off the burner cover plate and slide everything out.

Replacing Pilot Light

Separate the pilot assembly from the burner assembly and attach the new one. Work backward, putting everything back in place.  

Once everything is in place, reconnect the gas and open the shutoff valve and gas control knob. Relight the pilot and test to make sure that your water heater is working correctly.

Replace the Fuse

Replacing a fuse is similar to replacing a breaker, but much simpler. Once again, wear protective eyewear and get a flashlight so you have light while you work at the fuse box. 

Fuse Replacing

Find the fuse so you know which one that you are working on. If it’s not labeled, check for one that looks discolored, cloudy, broken, or melted – this is the fuse that you will be replacing. Before you start, make sure that you have a replacement with the same specs.

Switch off the main power. Unscrew the old fuse and screw in the new fuse, then turn everything back on.


If you have to fix your water heater, you can turn most of the problems into DIY projects. The cost of water heater parts is fairly inexpensive, at less than $50 for most components.  

If your water heater repairs are costing you closer to $1000, you might want to consider replacing your water heater, especially if you have an older water heater.

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