what to do with a leaking water heater

Water heaters can last a long time, but even the best ones can leak. A leaking water heater doesn’t mean that it needs replacing, but you will want to fix any leaks as soon as possible. Even a small amount of water can cause a huge amount of damage, so it’s important to asses the situation as soon as possible.

First, find where the leak is coming from. Even if a small amount of water is below your water heater, it may not be the water heater that is leaking. Wipe up the water and inspect the area. Are any of the fittings wet or are you seeing any other signs of leakage?

Check your surroundings for other possible sources of water. Is the water found near a window or another water pipe? Keeping gravity in mind, if your floor slopes at all, water may have traveled from another area to where you found it.

If you can’t determine the cause right away, put down some paper towels where you found the water and check back in a few hours to a day or two.

When you come back, If the towels are wet, then you know there is a problem and the water heater may be the culprit.

If you’ve determined that it is your water heater that is leaking, follow the steps below to asses the situation or just give us a call to have one of our skilled technicians come take a look. 

follow these steps to assess the situation


If you experience a leaking water heater, it is recommended to turn off the water to your tank. Your water heater tank should have a dedicated shutoff valve on the cold inlet pipes.

  • If this is a gate-style valve (a wheel that turns), turn the valve clockwise as far as you can.
  • If the valve is a ball-style valve, turn the handle 180 degrees.

Call us if you need help to talk through this at (866) 264-9642.

If the valve is broken, you can shut the water off to your home. Each home should have a main water shut off valve that would stop the flow of water to the entire house. If you are unable to locate this shut-off valve, please give us a call and we can schedule a time to have one of our service technicians out to your home to help you right away.


Follow the steps below for either an electric or a gas water heater.

Electric Water Heater

If you have an electric water heater and are experiencing difficulty, we recommend that you shut off the power at the breaker before working with the tank. Just flip the breaker to off.

Gas Water Heater

If you have a leaking gas-powered water heater, we recommend that you shut off the gas supply before working with the tank. There should be a dedicated gas shut off valve on the gas line leading to the tank. See below for a visual illustration of a gas water heater shut down.

Once your water and power have been turned off, you can better assess the situation and determine where exactly the leak may be coming from.

  • Check the inlet and outlet.
    Where pipes connect to your water heater are often sources of leaks. Check the cold water intake and hot water output connections.
    Are any of the fittings lose? They may just need to be tightened with a pipe wrench.
  • Check the pressure relief valve.
    The pressure relief valve, also called the T&P valve, may release water as a safety measure if too much pressure builds up. If your temperature is set too high, or if the water pressure to your home is excessive, pressure can build up causing leaks at the valve.
  • Check the thermostat settings to make sure the temperature is not turned up too high. (and you can check the pressure of your home using a pressure gauge at a hose bib) What temperature should your water heater be set to? Most manufacturers have a default setting of 140 degrees Fahrenheit, however, the Department of Energy recommends setting your tank-based water heater to 120 degrees Fahrenheit. If you are seeing water leaking from the T&P valve, either it’s doing its job by expelling water when the pressure builds up, or the valve itself is faulty. If your temperature is not set too high and you are still seeing leakage, the problem may be with the valve itself.
  • Check your water pressure.
    It’s also a good idea to check the pressure as well as the temperature. You can check the pressure by using a pressure gauge at the hose bib outside your house.
    What if my inbound pressure is too high? Your inbound water pressure should not be over 80 PSI per code,  and if the pressure is over 100 PSI, we strongly recommend you put in a pressure reducing valve. Your water pressure may not only be causing a leak, but it may also be causing damage to your fixtures.
  • Check the bottom of the water heater.
    Sometimes it can be difficult to determine the source of a leak, especially if water is collecting below the tank itself. Water leaking from a valve may run down the sides of the tank giving you the impression that the leak is coming from the bottom, but it’s really originating from the top or sides. If the leak is coming from the bottom of the tank, the tank itself may be cracked, which means it will need to be replaced.
  • Check the drain valve.
    Located towards the bottom of the tank, the drain valve should be closed completely, so make sure there is nothing leaking from this point. If it is leaking, the washer inside may be worn and need replacing.If you still can’t determine where the leak is coming from, give us a call and one of our technicians will be able to assist you.
    Regardless of what you find, it’s always best to have a professional inspect your water heater if you find any leaks. 
Water Heater diagram elec 1 1
Water Heater diagram Gas 1 1

Your water heater technician will drain your tank when they begin work.
However, if your tank is leaking badly, you may want to drain it immediately to prevent water damage.

If you need to drain your water heater before a technician arrives, follow these steps once the water and power have been turned off:

  1. Hook a garden hose to the drain valve at the bottom of the tank and run it outside on the ground. Make sure you drain the tank to a proper location such as a gutter drain or sink. Do not drain the water onto your lawn or driveway as sediment and rust from the tank can harm your grass or stain your driveway.
  2. Open the drain valve where the hose is attached.
  3. Open the pressure relief valve on top of the tank by pulling up on it.
  4. Allow the water in the tank to drain out.

Again, unless you are worried about severe damage, you don’t have to worry about draining your water heater. Our technicians will be happy to take care of this for you.  

Taking these first few steps when you discover a leak can be instrumental in avoiding water damage. If you have any questions at all, please don’t hesitate to give us a call at (866) 264-9642.


Loose Drain Valve:

One of the most common causes of water heater leakage is a loose drain valve. It water appears to be leaking from the valve, try tightening it with a wrench until it is snug, but be careful not to over-tighten it.


Too Much Pressure:

Sometimes a water heater tank can build up too much pressure which can cause leaks. This can happen with the water temperature is set too high or the exterior water supply is coming in at too high of a pressure for the tank.

Cracked Storage Tank:

Hot water heaters are built with a glass-lined storage tank. Over time, the natural minerals in the water can calcify and create deposits on the inside of the tank. These can crack the glass lining and cause your water heater to leak. Also, as water is heated, it expands. Over time, this expansion creates stress on the glass lining of the heater and can cause it to crack.

Unfortunately, when this happens, your hot water heater will need to be replaced; the cracks in the glass liner are not repairable. Sometimes, these leaks will not affect the performance or function of the unit and the people elect to wait to replace the water heater. As long as the leaking water isn’t causing damage, this is fine, but ultimately the unit will need to be replaced.

Other Reasons:

Lose fixtures, improper draining, and just age, are all reasons that your water heater may be leaking.
It’s always a good idea to do some troubleshooting on your own, but having a professional come in will always be the safest and best way to avoid potential long-term and expensive damage to your home.


Your Water Heater Isn’t Producing Hot Water

If your hot water heater is no longer providing hot water and the tank is electric-powered, check the fuse at the breaker and make sure it hasn’t flipped. If you have a gas hot water heater, you can also check the pilot light to determine if it is still operating. If neither of these simple fixes work, call to schedule a service call with a qualified technician to your home.


My Gas is Leaking – I Smell Gas!

If you believe you have a gas leak at the water heater, you can turn off the gas at the dedicated gas shut off valve on the gas line leading to the water heater. If you believe that you continue to have a gas leak problem, you can call Fast for service at (866) 264-9642.

In the case of a serious gas leak or emergency, it is always best to contact your energy company immediately.


After an Earthquake, Protect Your Home

If You smell gas:

  • Locate the meter outside your home. Turn gas valve ¼ turn from ON to OFF.
  • Contact your gas company

Waking up to a leaking water heater emergency is no one’s ideal way to start the day. But if you follow these steps you can prevent an emergency from becoming a disaster.


FOR A QUICK REPAIR AND INSTALLATION call Fast Water heater at (425) 636-7038 or fill out a contact form below. Our technicians are standing by.