Omnia Mechanical Group

571 Timpson Place Bronx, NY 10455

Phone: 212-534-2500

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Why Is My Water Heater Leaking From the Overflow Pipe?

A leaking water heater is a serious problem for any NYC apartment building owner. But when the leak is coming from the overflow pipe, it’s a sign of potential danger.  The overflow pipe is a safety feature designed to release water when the pressure or temperature inside the tank gets too high. Therefore, the question, “Why is my water heater leaking from the overflow pipe?” signals something is wrong with your system. Ignoring the problem can lead to scalding hazards, costly water damage, or even water heater failure. Discover the reasons for this type of leak and why professional help is crucial for a safe and lasting fix.

Top 5 Reasons Why Your Water Heater Is Leaking From the Overflow Pipe

1. Faulty Temperature and Pressure Relief Valve

The temperature and pressure relief, or T&P, valve is a critical safety component of your water heater. It acts like a pressure cooker release valve, opening when the water temperature or pressure inside the tank exceeds safe levels. This prevents potential tank ruptures and dangerous hot water surges.

Unfortunately, T&P valves are prone to failure and are often the reason for a leaking overflow pipe. Wear and tear, mineral buildup from hard water, or manufacturing defects can cause the valves to malfunction. A faulty valve may leak constantly or fail to open, creating noises and potentially hazardous situations.

Some building owners or maintenance staff may consider DIY T&P valve replacements, but this is a mistake. While the replacement is relatively straightforward for those with general plumbing knowledge and experience, the faulty valve may only be a symptom of a bigger problem. DIY installations also open the door to liability issues with potential legal ramifications. To avoid these problems, it is best to hire a licensed and experienced professional.

2. Excessive Water Pressure

A water heater leaking from an overflow pipe can also point to excessive water pressure. Ideally, water entering your building from the municipal supply line is within a safe, regulated range, ensuring plumbing fixtures work correctly without any undue stress. Unfortunately, water pressure can fluctuate, sometimes spiking beyond safe levels.

Some older properties may lack pressure-reducing valves or have malfunctioning valves. Without PRV valves, a property can experience consistently high water pressure.

Excessive pressure puts extra strain on your building’s water heater and components, like the T&P valve. The pressure can cause leaks from the overflow pipe and other areas in the plumbing network. Prolonged and excessive water pressure can cause premature wear and may result in burst pipes.

3. Thermal Expansion

Like most substances, water volume expands when heated in a process known as thermal expansion. In a water heater, the amount of expansion may seem small, but within the confined space of the tank, this small change equates to a significant increase in pressure.

Most older water heaters were closed systems, meaning they did not have a built-in mechanism to accommodate expansion and pressure changes. As the water heated, the pressure built with nowhere to go, putting extra stress on the tank and system parts. Modern water heaters typically include an expansion tank, which provides space for the expanding water while relieving pressure on the system.

A water heater leaking from an overflow pipe can occur in either system, although the problem is more common in older units that lack an expansion tank. Still, if a modern unit has a malfunctioning expansion tank, thermal expansion can cause a leaking overflow pipe, which can also result in premature failure.

4. Hidden Leak in the Tank

While malfunctions with the T&P valve or excessive pressure are common causes of overflow pipe leaks, sometimes the culprit is less obvious. Water heaters can develop hidden leaks, especially in older units or those deprived of regular maintenance.

Standard or traditional tank-style water heaters use anode rods to prevent corrosion in the tank and ensure longer lifespans. The rod is a sacrificial part made of magnesium, aluminum, or zinc-aluminum alloy. It attracts corrosive elements, drawing them away from tank walls. Depending on water quality and system specifics, these rods must be replaced every three to five years.

If a building owner does not have the rod replaced at recommended intervals, the corrosive elements it typically attracts will collect on the tank walls, causing corrosion. A corroded tank is prone to developing pinhole leaks, which may first show as leaks from an overflow pipe.

5. Incorrectly Installed Overflow Pipe

If your water heater is leaking from the overflow pipe, it can also stem from the incorrect installation of the pipe. While less common than other causes, poor installations can result in loose connections, incorrect routing, damage, and numerous other mistakes.

The overflow pipe typically connects to the T&P valve using threaded fittings. If these connections are loose or improperly sealed, even a properly functioning valve can cause leaking.

To drain correctly, the overflow pipe must route downward towards a safe exterior drain. If an installer angles the pipe incorrectly, it can cause a leak near the heater. Also, if the pipe becomes kinked along its route, it can impede water flow and cause leaks.

A professional from Calray Boilers can ensure the correct installation of overflow pipes and water heater systems. Working with a licensed plumber eliminates the risks of incorrect fittings, insufficient sealings, improper pipe routing, and potential property damage.

How Calray Boilers Can Help When Your Water Heater Is Leaking From the Overflow Pipe

Emergency Repairs and Annual Service Contracts

Why is your water heater leaking from the overflow pipe? There are several possible reasons, but they all point to a problem with your water heater that can worsen and result in costly damage and safety hazards. While you may be able to handle some issues temporarily in an emergency, always prioritize professional diagnosis and repair. Consider an annual service contract with Calray Boilers to reduce your risk of water heater problems. Our contracts include regular maintenance for anode rod checks and T&P valve inspections. If you’re facing a water heater issue, don’t hesitate to ask for help — call Calray Boilers at 212-722-5506.

Our Privacy Policy

Omnia Mechanical Group(the “Company”) strives to ensure the highest standards for property listings and customer information privacy. Please review the following statement to learn about our company practices and policies. Please be aware that our Privacy Policy is subject to change at any time.

1. Purpose.

This Privacy Policy (“the Policy”) provides information on how the Company uses your personal information. By agreeing to the Policy, you agree to our collection and use of your personal information as described in the Policy. This Privacy Policy is effective for all new users of

2. Personal Information.

You can browse some areas of (“the Website”) without being a registered user. However, certain activities do require registration. (You consent to the transfer and storage of your information by registering with We may collect and store the following personal information:

  • Name, email, address, telephone number, and (depending on the service used), move-in dates;
  • Transactional information (such as lease terms, lease parties);
  • Computer sign-on data, statistics on page views, and traffic to and from the Website; and
  • Other information, including IP address and other web log information.

3. Use of Information.

Our primary purpose in collecting personal information is to provide you with a safe and user-friendly experience. For example, the Company may use your personal information to:

  • Improve our services and the Website’s content and layout;
  • Provide the services and necessary customer support you request;
  • Resolve disputes, collect fees, and troubleshoot problems;
  • Track and record customer satisfaction with our services;
  • Protect the Company against error and fraud;
  • Inform you of special promotions and announcements;
  • Enforce our agreements, terms, conditions, and policies; and
  • As otherwise described to you at the time of collection.

We may occasionally ask you to complete optional surveys. These surveys are used to improve and customize your experience with

The Company always provides you the ability to opt-out of further communication such as promotions and surveys; see the Opt-Out section below.

The Company does not share any of your personal information with outside organizations, companies, individuals, etc. The only exception to this standard is if such a disclosure is reasonably necessary to respond to any and all legal processes.

4. Links to Other Sites.

The Website may have links to other websites that may collect personally identifiable information about you. The Company is not responsible for the privacy practices of the content of those linked websites.

5. Safety & Security Precautions.

The Website has strict security measures in place to protect you and your information from fraud. Once your information is provided to Antler Pump & Motor Corporation, we strive to ensure the confidentiality of your identity and information.

6. Opt-Out.

The Company provides you with the opportunity to opt-out of receiving promotional and other non-essential, marketing-related communications from Antler Pump & Motor Corporation. If you would like to opt-out of these select communications, please see any of the Company’s email communications and follow the directions indicated.

7. Account Protection.

Your password ensures the security of your account. When choosing a password, the Company suggests using various characters. It is highly recommended that you do not disclose your password to anyone. (If you do disclose your password or your personal information with others, you are responsible for all actions taken in the name of your account.) If the security of your password is compromised for any reason, please contact the Company immediately.

8. Accuracy of Information

The Company does not guarantee the accuracy of information for any and all of its properties on the Website, and is not responsible for any errors or misrepresentations (made by Renters, the Client, or otherwise).

9. Cookies

The Company may place a small cookie on your computer’s hard drive. This allows us to personalize your use on the Website. In order to maximize the functionality and usability of the Website, you must set your browser’s preferences to allow both permanent and temporary cookies.

10. Changing Your Personal Information.

Should your personal information change, please immediately update your information on the Website. This will ensure the accuracy of our records. The Company does retain personal information from closed accounts in order to comply with law and collect and disburse any fees owed.

11. Third Parties

This Privacy Policy addresses only the use of information we collect from you. Since does not control the privacy policies of third parties, you are subject to the privacy policies of those third parties. It is advisable that you consult with the management of third parties before you disclose your personal information to others.

12. General

We may amend this Privacy Policy at any time by posting the amended terms on the Website. All amended terms are immediately effective after they are initially posted on the Website.

13. Privacy Policy Questions & Concerns

Questions and/or concerns regarding the Policy should be emailed to the following email address: