Why Water Heater Is Leaking?

A leaking water heater is not only an inconvenience but also a potential safety hazard. There are quite a few things that can cause the unit to leak and, unfortunately, some of the issues can’t be fixed.

An old tank with cracks, a faulty or loose drain valve, pressure build-up, a corroded anode rod, loose inlet and outlet connections, and sediment build-up can make your water heater leak. While the connections and valves can be fixed or replaced, a leaking tank can’t be repaired.

How to Tell If Water Heater Is Leaking?

The first thing that you should do if you ever spot water under your water heater is try to figure out whether that’s a leak or condensation. The latter is totally normal and you should not worry about it.

However, if your unit has a leak, then you would have to try and fix it as soon as possible.

Here’s what you can do to find out for sure – lay a paper towel under the water heater (or over any area where you’ve noticed water). Check the paper every hour, if it doesn’t become wet in 24 hours, then it looks like the water that you have noticed before was condensate.

Read: What Is Water Heater Heat Pump? Everything You Need To Know

Is a Leaking Water Heater an Emergency?

If water is leaking from your heater, it means that there is something wrong with the appliance

There are a few minor issues that can cause a water leak, however, puddles under the unit might also be an indication of a very serious problem (like a gas leak or a pressure issue that can lead to an explosion).

Use the test mentioned above to confirm that your heater is leaking water, and if it is, give a call to a technician in the shortest timeframe.

Is It Bad If Your Water Heater Is Leaking?

Water leaks show that one of the unit’s components stopped working correctly. If you fail to fix the issue, the water heater will get permanently damaged (in the worst-case scenario, the unit might explode or cause a fire).

Another thing that homeowners would be concerned about is the house damage caused by the actual leaks. Your floors, walls, and subfloors can easily get damaged by the water.

Finally, a water heater leak can become a health concern as the presence of water can lead to mold growth.

Read: What Is A Hybrid Water Heater?

Can You Still Use Water If Water Heater Is Leaking?

Ideally, you would want to turn off the water and power supply as soon as you notice that your water heater is leaking. 

In the majority of cases, you’d still be able to temporarily use your water heater until the problem is fixed. Minor leaks especially won’t immediately affect the water usage.

But if you can stop using the heater before a plumber comes over, you should definitely do that. 

Can I Take a Shower If My Water Heater Is Leaking?

In general, it is safe to shower when your water heater is leaking. However, if you can avoid doing that, you should.

If you do not shut the water and gas supply, a minor leak can easily turn into a big one. This will increase the water damage and might lead to extremely serious consequences, such as gas leaks and, potentially, even an explosion. 

Depending on the tank size and the intensity of the water leak, you might not even be able to have a normal shower as the unit simply won’t have enough water.

Read: Does HVAC Include Water Heater?

Why Water Heater Is Leaking?

Old tank

If your water heater has a tank and it is older than 10-15 years, then the tank might have worn out. During these years, rust might have formed inside which then led to corrosion and the formation of cracks.

A drain valve that is not watertight

The drain valve is the part that you can use to empty the tank. It might become loose over time.

Too much pressure

If the steam has nowhere to go, the pressure inside the unit will increase and this will lead to water leaking from even the smallest cracks. 

The inlet and outlet connections are loose

The inlet connection lets cold water get in the tank, while the outlet connection allows the hot water to leave the unit. These will become loose over the years. 

Sediment build-up

If you haven’t been cleaning your tank regularly, then sediment might have collected at the bottom of the unit. Such build-ups can lead to the formation of cracks.

A corroded anode rod

The job of the anode rod is to, basically, attract corrosive substances. However, throughout the years, the component might practically ‘disappear’ and water can start leaking through the part of the unit where the anode rod used to be. 

Read: Ideal Temperature Of The Water Heater

Why Is Water Leaking from the Bottom of My Water Heater?

Bottom leaks usually occur when the actual tank has a crack or if the drain valve has become loose

Why Is My Water Heater Leaking Water from the Top?

In the majority of cases, there will be something wrong with the inlet and outlet connections. Cracks in the tank might appear at the top of the unit, but that is extremely rare. 

A loose relief valve and corrosion of the anode rod might also be to blame. 

Water Heater Leaking from Relief Valve

The main job of this valve is to relieve pressure inside the unit. If this component is not working correctly, then the pressure in the tank can become too high.

At times, all you would have to do is tighten the valve. If the component is faulty, you would have to get a new one.

Warning! Always lower the pressure in the unit before trying to fix the issue. 

What to Do If Water Heater Is Leaking?

  1. Make sure that it’s the actual water heater that is leaking.
  2. Turn off the water and the power supply. If you have a gas heater, turn the gas supply off as well. 
  3. Make sure that the inlet and outlet connections are not loose.
  4. Check the T;P valve – the temperature shouldn’t be set too high (check the thermostat) and the water pressure to your house shouldn’t be excessive (use a pressure gauge at the home bib to check that). The pressure shouldn’t be more than 80 PSI.
  5. Inspect the bottom of the tank for cracks.
  6. Make sure that the drain valve is completely closed.

Will a Leaking Water Heater Explode?

A leaking water heater can explode. 

You should be especially careful if the pressure relief valve is leaking. This would mean that the pressure inside the unit is way too high and the valve is not able to relieve that pressure.

A rotten egg smell (gas leak) and a popping noise are also indications that your water heater might explode.

Can a Leaking Hot Water Heater Be Repaired?

This will fully depend on the source of the leak. The majority of the components of the water heater can be replaced (like the drain valve, for example).

A leaking tank, unfortunately, cannot be repaired, so you might have to replace the whole thing. 

Read: The Best Temperature For The Water Heater And Why?

How Much Does It Cost to Repair a Leaking Water Heater?

ServiceAverage Cost
Anode rod replacement $150-$350
Pressure relief valve replacement$50-$300
Leak repairs$100-$1.000
New water heater replacement$600-$1.800
Tankless water heater replacement$800-$3.500

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

Without service, a leaking water heater will totally fail in anywhere from 5 minutes to, perhaps, about a month.

It goes without saying, that the unit should be repaired as soon as possible as a leaking water heater presents a serious safety hazard.

In general, a water heater can last for 10-15 years. If the problem was with one of the valves and you managed to successfully replace it, then the chances are high that the unit will be able to get to the end of its lifespan.

Does a Leaking Water Heater Need to Be Replaced?

You would have to replace your water heater if the tank is responsible for the leak. If the inside of the tank had corroded, then it would be impossible to replace it.

Loose connections, in their turn, can be tightened or replaced. If there is an issue with the valve, then you might simply have to replace the element without investing in a whole water heater.