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Reasons Your Water Heater Might Be Leaking

Waking up to the sight of a paddle under your water heater can be scary and overwhelming at the same time. You not only have to think of how to fix the leaks, but also think of the costs.

At times, a water heater leak could be inexpensive and simple to fit. However, you still need to know some of the reasons your water heater might be leaking.

There are a few common causes of water heater leaks. Let’s take a look at those as well of some of the signs of a leaking water heater. In some cases your water heater may still be usable, in others it may be time to replace it.

woman checking their water heater

Signs of a Leaking Water Heater

Apart from the usual sign of water dripping from your water heater, other signs indicate a leaking water heater.

Some of the signs to look out for include:

  • Malfunctioning controls
  • Rust and corrosion
  • Staining around the water heater
  • Puddle of water

Sometimes these signs can be easy to miss, especially if the leak is small. We have two water heaters at our house (a duplex) and after a recent water heater leak we purchased smart water sensors  to feel confident we’ll know right away when there is an issue.

How Long Will a Water Heater Last After it Starts Leaking?

The amount of time a water heater will last after it starts leaking depends on the source of the leak. If it’s the tank that’s leaking, you can use the water heater for another week, but you’ll need to replace the entire unit.

If the leak comes from loose valves or external pipe joints, you can have them tightened and the leaks fixed to continue using your water heater.

Can I Still Use Water Heater If It’s Leaking?

It is possible in most cases to still use your water heater even if it’s leaking.

However, you still need to know where the heater is leaking from and the extent of damage before it worsens.

It’s advisable to avoid using a lot of water until you have the leak leaking a gas water heater, switch off the gas supply, and avoid using the unit, especially if the unit floods and releases gas.

plumber installing a new water heater system

Reasons For a Leaking Water Heater

Different factors can cause water heater leaks. In certain cases, the reasons are small and you can fix them. However, other causes require the expertise of a plumber and sometimes may warrant a new water heater.

Some of the reasons for a leaking water heater include:

An Old Water Heater Tank

One of the common reasons why your water heater may start leaking is old age. A unit that is over 15 years is likely to start leaking as the parts have worn out. You may notice that the water  doesn’t stay hot like before and repairs may become a regular thing,

Rust formation as the unit ages can also contribute to leaks. Most heaters are steel-made, and steel is made of iron s bound to rust. 

Although some heaters have an anode rod that prevents rusting, using the heater over the years means the anode rod may fail or wear out.

Replacement is the best option when the water heater is old.

male thightening connection of the water heater

Loose Inlet and Outlet Connections

The inlet that allows cold water into the tank and the outlet supply line that lets heated water out to flow through the plumbing system can become loose over time. That can contribute to leakage.

You can tighten both connections to prevent this problem. Nonetheless, in some cases, you may need to replace the water lines if tightening the connection doesn’t fix the problem.

A Lot of Water Pressure

Pressure can become too much, which causes leaks through tiny cracks.

Note that water heaters are exposed to natural water pressure. The pressure happens when the hot water creates steam and occupies space. When the steam lacks an outlet, it’s forced to find small cracks and let this pressure off.  That contributes to leaks.

Heater pressure can also be high if the water gets into the tank at high pressure or when the water temperature is too high.

man adjusting temperature of water heater

Malfunctioned Temperature and Pressure Relief Valve

Most water heater tanks have a temperature and pressure relief valve at the top. In case of a lot of pressure, the steam escapes through these valves and allows the pressure to go back to normal.

In some cases, the valve may get loose and lead to water leaks.  If there’s water leaking from the valve threads, you’ll need to replace them.

The plumber will replace the T&P valve by turning off the water supply to the unit and draining the tank until the waterfalls below the valve level.

He will open the hot water valve to allow air into the tank.

After unscrewing the valve, he will check for corrosion. In case of rust, the entire thing will need replacement. If there’s no corrosion, the T &P valve threads are wrapped in Teflon tape and screwed back into the unit.

It’s a good idea to test your pressure release valve. We set this up on a schedule for every 6 months.

Keep in mind that a bad pressure relief valve can be a major safety issue. If pressure builds up in a water heater can cause your water heater to explode.

If you believe the valve is causing issues with your water tank, its best to turn the water heater off until a plumber can come out and look at it.

sediment buildup in water heater

Sediment Buildup

Failing to maintain your water heater and flushing it can lead to sediment build-up at the bottom of the tank.  The sediment causes the tank to crack, which can lead to water leaking into your home.

If your water heater starts leaking due to crack formation, you may need to replace the entire unit.

Faulty Drain Valve

The drain valve is mostly used to empty and clean the water heater tank. Over time, the valve can become loose due to continuous usage, leading to a mild water leak. Sometimes tightening the loose connection and tightening the nuts can solve the issue.

However, if tightening doesn’t solve the issue and the valve is still leaking, it’s mainly because the valve has malfunctioned and needs replacement.

Internal Tank

The internal tank holds the water, while the external tank has insulation to keep the water warm.

When there’s a leak in the internal tank, it’s usually due to sediment buildup or age.

Other Causes

If you have an electric water heater, it has two heating elements to heat your water.  These heating elements go into the tank and make contact with the water.

Gaskets are installed at the point of entry to prevent leaks.

Sometimes the gaskets get damaged, leading to leaks. Replacing the gaskets will solve the leak issue.

man repairing water heater

Is Leak Location Essential?

Yes, understanding where a leak is coming from can help determine its cause. It also makes work easier as you don’t have to inspect your entire unit and the plumber can quickly make repairs.

Some of the common places your water heater may leak include:

Top of the Tank

Water leaks can occur at the top of the tank due to inlet and outlet connections.  Having loose temperature and pressure valves can also produce leaks at the top of the tank. Anode rod corrosion can also lead to leaks at the top. Part replacements or tightening can fix these types of leaks.

Bottom of the Tank

Faulty drain valves or loose drain valves are the main causes of the bottom of the tank leaks. Tightening or replacing the valves can help fix the leaks.

It’s critical to note that bottom leaks can also be due to a crack at the bottom of the tank.

Leaks Inside the Tank

It’s impossible to tell if you have a leak inside your tank from the outside. You’ll need an experienced plumber to diagnose the problem.

These types of leaks form pools of water under the tank. The problem often occurs when the water heater is more than 15 years.

Undetermined Location

If you can’t tell where a water leak is coming from, it’s possibly due to a lot of pressure.

These leaks occur when the system needs to relieve the pressure, but have no outlet.

man checking water heater

Tips to Prevent Water Heater Leaks

It’s possible to prevent water heater leaks and save on costly repairs by:

Inspecting the Water Heater Frequently

Regularly checking your water heater can help you identify and spot problems early. You can tell when your heater has a problem if you’re used to inspecting it.

When inspecting your water heater, ensure that you tighten loose parts.

Call Your HVAC Expert For Preventative Maintenance

Having an HVAC professional maintain your unit and make the necessary repairs can help reduce cases of water leaks and increase the heater’s efficiency. Additionally, a plumber can tell if there’s an imminent leak and attend to it.

Clean the Tank

Flushing out your tank removes any sediment that has built up over time. Empty the water using the drain valve. That will improve the water quality and prevents cracks that occur due to sediment collection.

Moisture at the vent

Gas water heaters have vents to allow combustion byproducts out.  When the vent becomes obstructed or obstructed, it can lead to moisture formation as the combustion gases condense.

Check the flue pipe and vent for any signs of obstruction or damage. Call your plumber if the flue pipe needs to be replaced or repaired.

Final Thoughts

Your water heater can leak due to various reasons. While it’s easy to tell some of the causes, sometimes you need a professional to determine the location of the leak and make the necessary repairs.  An experienced plumber will also advise you on whether repairs are enough or you’ll need to replace your entire unit.