It’s something most of us have experienced at some point: waking up in the morning, looking forward to a nice hot shower to get the day started, and getting only ice-cold water from the faucet. If this is happening to you, you need to know why and what you can do to get the problem resolved. Keep reading to learn about some of the most common reasons for a lack of hot water in your home.

Type of Water Heater

The type of water heater you have will determine where you need to look first to locate the problem. Three main types of water heaters are commonly used in homes, and yours will likely fall into one of these categories:

  • Traditional gas heater with tank
  • Electric heater with tank
  • Tankless on-demand heater (either gas or electric)

If you suddenly discover your home has no hot water, knowing which type of water heater you have will allow you to start troubleshooting to find out why the heater isn’t providing hot water.

Gas Tank Heater

This traditional type of water heater uses gas to heat water, storing it in a tank until it’s needed. When you shower, do laundry, wash dishes, or use hot water for other household tasks, the hot water comes from the supply in the tank. The tank then has to refill and heat the new supply of water.

If you have a gas tank heater, go through the following checklist to identify the reason. 

    • Someone used all the hot water – One of the simplest reasons for not having hot water is because someone in the home has used it all up, so you’ll need to wait a half hour or so until more water heats up. This isn’t a big problem in itself, but if it happens frequently, it could indicate your tank is too small for the number of people in your home, and you may need to upgrade to a larger one.
  • The thermostat isn’t set correctly – The thermostat controls the water temperature, and if someone has inadvertently turned it down, the water won’t get as hot as you want. The best water temperature for household use is 122–140°F, so check the thermostat to see if it’s set to that range. If not, turn it up and wait about 30 minutes, then test the water temperature again.
  • The pilot light has gone out – In older water heaters, the pilot light stays on all the time so it’s ready to fully ignite whenever the water in the tank needs to be heated. If the pilot light has gone out, the heater won’t be able to heat the water. You can open the panel and see if the pilot light is out. If it is, relight it by following the instructions attached to the side of your water heater. This usually involves lighting it with a long lighter or pressing a button. 
  • There’s a problem with the thermocouple – This is the device that cuts off the flow of gas if the pilot light blows out. This is extremely important because if the pilot light gets blown out but the gas keeps flowing, it will create a serious risk of explosion. However, if there’s a problem with the thermocouple, it could cut off the gas supply when it shouldn’t. Check to make sure the copper tube of the thermocouple is sitting in the flame. If it isn’t, adjust it so it does.
  • There’s a problem with the ignitor – In a more modern water heater, the pilot light doesn’t burn all the time. Instead, it’s lit by an ignitor when water needs to be heated. If the ignitor breaks, the pilot light won’t be lit when hot water is required. If you have this kind of water heater, check the ignitor’s function by pressing the ignition knob. If nothing happens, you’ll need to replace it.
  • There’s a problem with the gas-to-air ratio – If you can see the pilot light burning but it’s an orange-yellow color, it could be a sign the mixture of air and gas is wrong. The pilot light should burn blue, so if yours burns yellow, call a professional to check it. A yellow flame can also signal the presence of carbon monoxide, which is a potentially lethal gas, so turn off the gas, open all windows, and be alert for any signs of carbon monoxide poisoning, such as dizziness, fainting, or nausea.
  • There’s an issue with the gas supply – If your issue isn’t related to the pilot light or ignitor, your problem could be with your gas supply. First, check to see if there are any bends or kinks in the gas line that could be keeping the gas from reaching your heater. Next, make sure the gas is turned on, and check the gas valve. If you don’t find any obvious reason for why your gas isn’t reaching your heater, call your gas company for assistance. 
  • There’s a gas leak – If you detect an odor that smells like rotten eggs, you could have a gas leak, which is extremely dangerous. If you suspect you have a gas leak, turn off the gas supply immediately, open all windows, go outside, and call the gas company right away.
  • There’s a water leak – If your water tank is leaking, cold water won’t have the chance to get heated up. If your drain valve, cold water valve, or pipe connection is the source of the leak, it may be possible to have it repaired. If it’s coming from somewhere else, you may have to replace your water heater. Call a professional plumber if you find a water leak.
  • There’s corrosion in your tank – If you have an older tank, it may be starting to corrode, in which case your water will probably look dirty and have a metallic smell or taste. If the inside of your tank is corroding, you may need to replace it.
  • There’s a buildup of minerals – Mineral buildup can cause a water heater to stop functioning properly. Check inside for mineral or sediment buildup. If you find it, it may be possible to clean it out and fix the problem.

Electric Tank Heater

Some water heaters operate on electricity instead of gas. These types of heaters can experience many of the same problems as gas heaters, so start by asking the same questions:

  • Has someone used all the hot water?
  • Is the thermostat set high enough?
  • Is there a water leak?

There are some additional things to check if your water heater is an electric type:

  • The circuit breaker was tripped – If the circuit breaker has been tripped, your heater isn’t receiving electrical current. Check your circuit breaker box. If you discover one of the switches has been tripped, move it back to the “on” position and see if the water is now being heated. 
  • The temperature cutoff switch is malfunctioning – The high temperature cutoff switch is there to keep your system from overheating. If it’s faulty, it won’t allow the water to be heated. If the cutoff switch has been flipped off, simply flip it back on. If that doesn’t fix the problem, the switch may need to be replaced.
  • The heating elements are defective – An older heater is especially susceptible to having its heating elements fail, which may indicate it’s time to replace the heater.

If your water heater still isn’t functioning properly, try simply turning it off, waiting a minute, and turning it back on again. This is like hitting a reset button, and it may get your heater operating correctly again. If that doesn’t work, try calling a professional electrician for assistance.

Tankless Water Heater

A tankless system can run on either electricity or gas (such as a propane tankless water heater), so they can have some of the same issues as the tank heaters described above. If your tankless water heater is powered by gas, check the pilot ignitor, the gas supply, and the other features listed for a gas tank heater. Since there isn’t a tank, you can skip the steps related to that element.

If you have an electric tankless water heater, check the features like the circuit breakers.

However, there’s one additional factor to consider with on-demand heating systems—the outside temperature. Since on-demand systems work by heating water as it’s needed, during the summer, the water that comes from outside may be much warmer than it is in the winter. A heat setting that gives you hot water in summer may not be high enough to heat your water in the colder months, so you may discover your water quickly becomes much hotter if you simply turn up the heat setting. If none of these steps work, your best bet is to seek help from an electrician.

Replacing Your Water Heater

As with other household appliances, water heaters need to be replaced occasionally, and the type of heater affects how often you need to change it. Traditional hot water tank heaters typically need to be replaced every 10–15 years, so if your heater is getting older, you should think about replacing it before it completely breaks down and suddenly leaves you without hot water. 

Tankless water heaters, on the other hand, perform better and longer, so they usually last 20 years or more before they need to be replaced. On-demand water heaters are convenient because they don’t waste energy to heat water when it isn’t needed. They can provide all the hot water you need whenever you need it, so you’ll never have to take a cold shower.

Clearly, there are a lot of potential reasons for why you’re not getting hot water. By working through the various possibilities in a methodical way, you probably won’t have too much trouble finding the problem. Your issue may be related to the type of water heater you have, and with the information offered here, you have a good place to start when you’re searching for the cause of your hot water troubles.

If your water heater is no longer functioning properly and it’s time to replace it, reach out to the pros at Arnett’s Water Systems. We’re available 24 hours a day, 7 days a week. When you need highly trained professionals to help you choose the best tankless water heater for your needs, you can trust us to provide nothing less than exceptional service. Give us a call today at (619) 223-1209 to find out how we can help you make the choice that’s right for you.