How to install Heat Traps on Water Heaters: Detailed Instructions

When it comes to maintaining the efficiency of your water heater and reducing energy costs, knowing how to replace heat traps is crucial.

In this guide, we'll discuss the necessary steps for homeowners and DIY enthusiasts to replace heat traps confidently, ensuring their water heating system remains as efficient as possible.

From understanding the required tools to addressing common challenges, this guide will provide you with the knowledge needed to undertake this energy-saving project.

What are the heat traps?

Heat trapsHeat traps

Heat traps serve a vital function in both electric and gas-powered water heaters, acting as guardians against unnecessary heat loss when there's no water demand.

By preventing the escape of hot wate-and thus, the associated heat energy-during periods of inactivity, heat traps ensure the system's efficiency is not compromised. This preservation of heat within the system is critical for maintaining optimal performance and reducing energy consumption.

This necessity becomes even more apparent when considering thermosiphoning, a process where hot water naturally rises and exits through the cold water inlet or dip tube due to thermal expansion.

This instance of natural convection results in significant energy wastage as hot water unnecessarily circulates without being utilized.

Identifying the occurrence of thermosiphoning is straightforward-if the cold water inlet pipe feels warm or hot, it indicates that heat is being lost, pointing to the absence, malfunction, or incorrect installation of heat traps.

Effectively managing thermosiphoning through the use of heat traps is pivotal, as it not only mitigates energy loss but also aids in reducing operational costs and utility bills.

This highlights the importance of understanding and properly installing heat traps. Indeed, such measures are crucial steps towards optimizing the performance and efficiency of water heating systems.

Exploring heat trap types

In the realm of tank-type water heaters, brands like Rheem, AO Smith, State, American, Bradford White, and others now commonly incorporate heat traps on both the hot and cold pipes to enhance energy efficiency.

For units lacking this feature, retrofitting with heat traps is a viable option. Among the varieties available, the most prevalent types are those equipped with metal nipples featuring internal flaps or balls.

Heat traps designed with flaps are often favored for their compact size and their contribution to quieter operation of the water heater.

Conversely, the ball type, while effective, has a tendency to get stuck, which can lead to a reduction in water flow. This limitation is significant enough that some plumbers opt for a different approach, creating heat traps by manually bending the pipes into a U-shape, commonly referred to as a gooseneck.

This manual method of forming a gooseneck offers distinct advantages over factory-installed heat traps.

Notably, the absence of moving parts eliminates the risk of components becoming lodged and impeding water flow.

However, it's important to be aware of the common issues associated with heat traps, such as flow restriction, lack of hot water, and noise-challenges that are particularly pronounced in systems with a recirculation loop.

The gooseneck design, by virtue of its simplicity and reliability, provides a compelling alternative for those looking to sidestep these potential pitfalls and maintain efficient, trouble-free operation of their water heating system.

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How to install heat traps: A step-by-step guide

Tools and materials needed

Before beginning the installation process, ensure you have the following:

  • Adjustable wrenches or pipe wrenches
  • Teflon tape or pipe joint compound
  • Heat traps or heat trap nipples (compatible with your water heater)
  • Pipe insulation
  • Bucket and towels (for water cleanup)

Step-by-step installation process

  • Safety first: If you own an electric water heater, ensure your safety by turning off the electricity at the circuit breaker to eliminate any risk of electrical shock. For gas water heaters, cut off the gas supply to prevent any leaks or dangers, and make sure the pilot light is extinguished.
  • Water supply: Turn off the main water supply to the heater. If needed, drain the tank to relieve internal pressure and prevent water spillage during the installation.
  • Disconnect pipes: Use wrenches to carefully disconnect the cold water inlet and hot water outlet pipes from the top of the water heater. This step requires some caution to avoid damaging the pipes.
  • Remove old components: If there are old heat traps or nipples present, gently remove them. Be particularly mindful not to strip or damage the threads on the water heater, as this could lead to leaks or issues with installing the new traps.
  • Prepare the threads: Apply Teflon tape or pipe joint compound to the threads of the new heat traps or nipples. This helps ensure a watertight seal and prevents future leaks.
  • Install heat traps: Carefully screw the new heat traps into the appropriate ports on the water heater. It's crucial to note the direction of flow as indicated on the traps to ensure they are installed correctly.
  • Reconnect pipes: Reattach the cold and hot water pipes to the heater. Double-check to make sure all connections are tight and secure to prevent any potential leaks.
  • Insulation: Wrap the pipes and newly installed heat traps with insulation. This extra step further prevents heat loss, maximizing the efficiency of your water heating system.
  • Restore supplies: Turn the water supply back on and inspect all connections for leaks. Make any necessary adjustments to tighten the fittings. For electric water heaters, switch the power back on at the circuit breaker. For gas heaters, relight the pilot light if it was extinguished and reopen the gas supply.

Potential problems and obstacles

Navigating potential heat trap problems and obstacles is an integral aspect of any home improvement project, including the installation of heat traps on water heaters.

Despite its straightforward nature, this task can encounter various challenges that homeowners and DIY enthusiasts should be prepared to address.

Leaking fittings

If leaks persist after installation, it may indicate that the connections need further attention. Reapplying Teflon tape or pipe joint compound and ensuring the connections are tightened adequately can help resolve this issue and prevent water wastage.

Noise issues

While a rumbling or ticking noise from heat traps is typically harmless, it can occasionally be bothersome. Ensuring that the traps are securely fitted can often alleviate this noise, providing a quieter operation for your water heater and a more peaceful environment in your home.

Reduced water flow

Improperly installed heat traps may inadvertently restrict water flow, leading to reduced efficiency. If you notice a decrease in water flow, it's essential to check the orientation of the traps and ensure they are correctly aligned.

Additionally, inspecting for any debris that may be obstructing the valves can help restore proper water flow and optimize the performance of your water heating system.


Understanding the function and importance of heat traps can help you maintain your water heater's efficiency and save on energy costs.

By following the detailed steps outlined above, homeowners and DIY-ers can confidently replace heat traps, ensuring their water heating system operates effectively.

Remember, safety is paramount, so take the necessary precautions and consult with a professional if you encounter any issues beyond your expertise.

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