Why Water Heater Leaking from Bottom?

A water heater leak should be fixed as soon as possible if you don’t want your house to get flooded. Thankfully, some leaks are relatively easy to deal with.

In the majority of cases, your water heater will start leaking from the bottom if the drain valve is loose or faulty. Even though the T;P valve is located at the top of the unit, it has a pipe that can start leaking on the floor. By the way, water heaters can also develop cracks at the bottom of the actual tank.

Below you will find step-by-step instructions on how to fix a leaky water heater.

Why Water Heater Leaking from Bottom?

Usually, one of the three following issues will cause your water heater to leak from the bottom.

The temperature and pressure relief valve is leaking

This valve is a safety device that is designed to release excess pressure from the unit. The T;P valve comes equipped with a tube that runs to the floor. If the bottom of your water heater is leaking – check this tube for moisture (if the element is wet, then the valve is to blame).

The drain valve is leaky or faulty

Water heaters have a drain valve at the bottom that you can use to drain the tank whenever you need to perform maintenance or get rid of sediment buildup. If the water is dripping from the valve, then the chances are high that you would have to replace the element. 

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Read: Why Water Heater Not Heating Well? – Troubleshooting Guide

The tank has a crack in it

If the actual tank is leaking water, then it looks like there is a crack in the unit. 

What Do You Do If Your Water Heater Is Leaking from the Bottom?

  1. The first thing that you should do is confirm it’s the water heater that is leaking. If you have noticed that the unit is evenly covered in moisture, then it is most likely condensation (which is not a concern).
  2. If the water is dripping from the water heater, then make sure to turn off the power supply to the unit. If you have an electric appliance, then flip the circuit breaker. If you have a gas water heater, then don’t forget to find the gas shutoff valve.
  3. After that, shut off the cold-water supply. Look for the valve on a pipe that is indicated by blue. If your equipment is not color-coded, then you can simply touch the pipes, to find out where the cold water is flowing.
  4. Now you would have to look for the source of the leak. Find the exact place where there is moisture buildup, wipe the area down, and then come back in a few hours. If the water has accumulated once again in the same place, then this is the source of the leak.
  5. You might have to replace the temperature and pressure relief valve or the drain valve or get a new water heater altogether (if there is a crack in the tank).

New Water Heater Leaking from Bottom

If your new water heater is leaking from the bottom, a faulty pressure relief valve or a leaky drain valve might still be to blame.

If the unit was installed in a hurry, then there might be a poor connection or a poor fitting. You can try adjusting the gaskets, joints, and connections to see if that helps. 

Read: How To Keep Your Water Heater From Freezing?

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AO Smith Water Heater Leaking from Bottom

SymptomsPossible Causes
Puddle on the floorA leaky tankA leaky fittingCondensationIssues with the temperature and pressure relief valve
A leaky fittingCorroded threadsPoorly sealed threadsA leaky weld at the spud 
Leaky temperature and pressure relief valveThe water inside the tank is too hotNormal thermal expansionIssues with fitting sealA leaky weld at the spud

Rheem Water Heater Leaking from Bottom

The most common reason for a Rheem water heater leaking from the bottom is a defective or loose drain valve

Make sure that the valve is completely closed (you can use a pipe wrench to fasten it). If that didn’t fix the issue, then you might have to replace the drain valve.

Tankless Water Heater Leaking from Bottom

Tankless water heaters can develop leaks as well. The joints and pipes, for example, might start leaking after years of use. If your area has acidic water, then the metal parts of the unit can get affected over time and develop a pinhole.

You would have to also make sure that your unit is operating at a low water flow rate. Tankless water heaters are designed to work in such a way, and if the water flow rate is way too high, the unit might develop a leak. 

Read: Why Gas Water Heater Not Working After Power Outage – Troubleshooting Guide

How Do I Stop My Water Heater from Leaking?

In the majority of cases, all you would have to do to stop your water heater from leaking is tighten one of the valves or replace it. 

If your unit has developed a crack in the tank, then you would have to replace the whole water heater. To make sure that such a situation never happens again, install a powered anode rod that will protect the unit from oxidation and rust, and don’t forget to replace the anode rod every 2-3 years or so. 

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

It can cost you between $50 and $300 to replace a pressure relief valve and the replacement of a drain valve shouldn’t cost more than $200.

If a cracked tank is what’s causing the leak, then you would have to replace the water heater. Be prepared to pay $1,300-$5,500 for that. 

Read: Why Does A Gas Water Heater Make A Knocking Noise?

How Long Will Water Heater Last After It Starts Leaking?

Water heater leaks should not be ignored. A leaky drain valve is a relatively unproblematic issue that might not require your full attention as long as you put a bucket underneath the unit.

However, a leaky T;P valve might indicate that there is too much pressure buildup in the tank and that is simply unsafe (the unit can literally explode). If the tank is leaking, then you might be able to continue using the water heater for around a week or so, but bear in mind that you never know when the crack will ‘open up’ and flood your house.

Can I Shower If Hot Water Heater Is Leaking?

It is best to turn off the water heater and not use it until the issue is resolved. You might be able to take a shower or two, but the risk is simply not worth it. 

By the way, the water heater can stop working, if it detects a leak in the system.

Read: Water Heater Trips Breaker After A Few Minutes – Troubleshooting Guide

Can a Water Heater Leak Cause a Fire?

If you end up not paying attention to the issues that your water heater has developed, the unit might end up causing a fire or even exploding. 

A leaky temperature and pressure relief valve, for example, can indicate that the temperature or pressure inside the water heater has exceeded the safety limits. And turning the device off, in such a case, would be the best possible decision. 

Where Do Hot Water Heaters Leak From?

Water heaters can leak from the top or the bottom. Determining what part of the unit is leaking, can actually help you find the root cause of the problem.

  • The heater will be leaking from the bottom if there is an issue with the drain valve, if the tank has developed a crack at the bottom, or if there is water coming out of the pipe connected to the T;P valve
  • Top leaks occur, if the connections weren’t installed correctly, or if the actual T;P valve is leaking


In the majority of cases, a water heater would be leaking from the bottom, if the drain valve is either loose or faulty. The temperature and pressure relief valve and a crack in the actual tank can also be to blame.