A Guide to Prevent and Fix Flooding Water Heaters

Flooding water heaters can be disastrous for your home and your wallet. If you want to prevent it from happening and learn how to act when it happens, keep reading and find out!

Water heaters are designed to deal with water in and out, day and night. With time, these pipes, tanks, and elements tend to start leaking out due to corrosive water nature and many other factors such as sediments that can speed up the corrosion process.

Leaks can be large enough to cause flooding, which is pretty frustrating and even dangerous to experience.

Checking water leaks in water heaters

Gas water heaterGas water heater

Preventing flooding is all about testing your water heater at least once a month to see how it works. The best ways to check on your water heater is by following these steps:

Check if there is any dripping or water sign around or below the water heater. If there is much water, more likely it is a leak happening. If it is little, maybe it is just condensation that is pretty common on these devices.

Then check vents, the sides of the tank, and piping connections. Ensure none of these is leaking or doing excessive condensation, which could be a sign of internal leaking. On the other hand, tankless devices, should not create condensation and are a lot easier to check.

When you have already checked the tank sides and vents, it is time to start checking up the pipelines and temperature and pressure relief valve. The pipelines contain water in high pressure, while the T&P valve's primary purpose is to release this pressure by leaking little water. If the pipes are not leaking, it may be the T&P valve that could leak due to the high pressure, but if it is not, you may still have an additional problem.

Drain valves are the last option for leaking. These valves' main purpose is to drain the water inside the tanks when needed, whether it is for cleaning or getting rid of the water inside. Sometimes, these valves open themselves when there is much pressure or merely get defective and broken, so they need replacement.

Water pipelines and internal leaking are the worst to check. Internal leaking, however, demands much more than just checking, as they could harm the device and even cause electrical problems.

Pipe fitting leaking is often fixed by tightening the elements. If there is a rupture in the pipe, that section has to be fixed/replaced. However, if any of these happens, your best choice would be to call a professional plumber or technician accordingly.

Preventing water heaters flooding (devices)

Even when continually checking your water heating device in search of leaks and condensation, there is still a great chance you overlook a problem that could escalate very quickly. To avoid flooding when a leak is ignored, we recommend using one of the following devices:

Drain pan

Using a drain pain is pretty straightforward. You just need to drain the water heater and move it to place the drain pan below it. This pan has a hole in which you will attach a rubber piping connected to a drain pipe, and that's it. Every time the water heater starts leaking water, it will directly go down the drain pan and drain pipes. However, if the leak is too big, maybe the drain pan won't be enough. A big drain pan such as the Camco 20932 30x30 is an excellent option in these cases.

Shut-off valve

The shut-off valve helps to turn off the main line of water in appliances such as a water heater, water softener, or even in the main water pipe. There are hundreds of options for these valves, and one of the good buys is the FloodStop Auto-Shutoff.

The FloodStop will automatically shut off the valve and ring an alarm as soon as it detects water leaks. It is a fantastic way of preventing flooding, maybe the most effective.

Water alarms

Leak alerts such as the Zircon 68882 with WiFi are excellent choices to avoid flooding. It will not only turn on an alarm ring at 105 dB when it detects a leak or minimal flooding, but it will immediately send a message to the owner's cellphone thanks to its WiFi connection feature. Most alarms are very loud nonetheless and will quickly help prevent flooding when needed.


Timers allow users to set a time and schedule when the water heater will be turned on and when it will switch off. These devices are pretty easy to use, long-lasting, and incredibly reliable. An excellent choice is the Intermatic T104 Mechanical Timer, which works at 40 AMPs and 240 V so that it can be used with the biggest and most potent water heaters without problems.

Smart controllers

These controllers are everything you need to prevent flooding and other appliances' malfunctions. They are entirely easy to use and install and provide a very effective flooding alert in most cases.

The Quanta Water Heater Controller, for example, allows users to change the temperature of the device, detect when there is a leak, schedule the device activity, and much more with a simple cell phone app. The only thing a smart controller needs to function is a stable WiFi connection.

emergency plumber

How to fix flooded water heaters

Sometimes, flooding is almost impossible to avoid. When it happens to your water heater, there are a few steps you should follow to prevent further damage to the surrounding and salvaging what matters the most.

Drain all the water in the flooded place, but make sure electrical connections are switched off first to avoid shorted circuits.

  • Check the water heater, especially if it is an electrical one or a gas one with a tank. Shut off the gas valves, if any, switch off water lines, and let the tank drain as well. After emptying the tank, clean it up to make sure it is not contaminated.
  • Do not let any contaminated water enter the tank or the water heater if it is dry. If it is all wet inside, you may need to wait a few hours or days until it dries out.
  • If the device was contaminated with water, it would very likely need a deep clean before using it. If the water was filthy with water from drain pipes, it is almost obligatory to replace the entire device to avoid infections later.
  • Make sure any electrical components such as controls, motors, and pumps are in a good state. If not, the device won't work.
  • Check the burners, insulation, heating elements, and others. These should be dry as well and without any blockage in the case of burners. These can be fixed by cleaning and waiting for them to dry entirely.
  • Recheck everything, from the power source to the electrical wiring, fuel supply, connections, pipes, controls, and everything in between and related to the water heater.
  • If the device wasn't contaminated and all the insides and components are dry, and in a good state, you will need to try the device. Before, however, make sure that everything from pipelines and heat sources is checked and in decent condition as well.
  • If the device turns on, now you need to look for the cause of the flood. Most likely, it was a valve or piping problem. Check everything as indicated in our "Checking Water Leaks" section, and find the flooding cause.
  • If it doesn't turn on, you will need to call a specialist to check the device. Most likely, you will have to buy another water heater.
  • If the device turns on, then you can start opening water pipelines, fuel sources and let the device work as it usually would.
  • Monitor its functioning for at least an hour to make sure it works well. Open up a faucet or sink nearby to see if it exerts hot water. If it does, you have fixed your device.
  • If it doesn’t, try out our “Troubleshooting No Hot Water Issues with Water Heaters” guide.
  • Always consider calling a professional after a flood. It will save you time and prevent any damage to the device or yourself. Sometimes, it may even save you a few bucks.

Want to avoid or fix a water heater from flooding?

There's nothing worse than having to clean water heaters after a flood, both for the time and money these repairs take. That's why it is utterly essential to be constantly checking the device in search of leaks and other flooding signs and having suitable devices and prevention approaches to avoid flooding from happening.

Water heaters should never flood, but as disasters can happen – there's nothing better to be secured. Use our advice and recommendations to avoid any flood happening to your water heating device!