Is your aging water heater showing signs of wear and tear, or are you simply tired of running out of hot water? The solution might be closer than you think. Making the decision to replace your old water heater with Navien tankless is a popular choice for homeowners looking to modernize their home, increase energy efficiency, and enjoy the luxury of endless hot water. Navien is a leading name in the industry for a reason, offering high-efficiency units that provide consistent performance and significant long-term savings. This article will walk you through the key benefits and important considerations when you decide to replace old water heater with Navien tankless, transforming your home’s hot water system for the better.

What are the Benefits of Replacing an Old Water Heater with Navien Tankless?

The advantages of a tankless water heater conversion are compelling and go far beyond just having continuous hot water.

1. Energy Efficiency and Savings: This is often the primary motivator for homeowners. Unlike a traditional storage tank that constantly heats and reheats water, a Navien tankless unit only fires up when you turn on a hot water tap. This on-demand operation eliminates standby energy loss, which can account for a significant portion of a tank-style water heater’s energy consumption. By choosing to replace your old water heater with Navien tankless, you can see a noticeable reduction in your monthly gas or electric bills.
2. Endless Hot Water: The biggest quality-of-life improvement is the unlimited supply of hot water. No more waiting for the tank to refill after a few showers. A Navien unit heats water as it flows through the system, ensuring you can run the dishwasher, washing machine, and a shower simultaneously without a drop in temperature. This is a game-changer for large families or homes with multiple occupants.
3. Space Savings: Traditional water heater tanks are bulky and take up valuable floor space in a basement, closet, or utility room. Navien tankless units are compact, wall-mounted systems. This frees up space that can be used for storage, a workbench, or any other purpose, which is a major benefit for smaller homes.
4. Longer Lifespan: A typical tank water heater lasts 8-12 years. Navien tankless water heaters are built with durable components, including dual stainless-steel heat exchangers, and can last for 20 years or more with proper maintenance. The longevity of these systems means you’re not just making a short-term upgrade, but a lasting investment in your home.

Are There Any Installation and Compatibility Issues When I Replace Old Water Heater with Navien Tankless?

While the benefits are clear, the process of a tankless water heater upgrade requires professional expertise. It is not a DIY project. A professional plumber will need to address several key considerations to ensure a successful and safe installation.

First, gas line sizing is critical. Tankless units, especially high-capacity ones, require a larger volume of gas to operate efficiently compared to a traditional tank. The existing gas line to your old water heater may not be sufficient, and a professional will need to run a new, larger gas line. This is a non-negotiable step for proper and safe operation.

Second, venting requirements are different. Most old water heaters use a simple B-vent or a chimney for exhaust. Navien’s high-efficiency condensing units require a new venting system, typically made of PVC or CPVC pipe. This is because the exhaust is cool enough to be vented through plastic, which also allows for more flexible installation locations. The plumber will handle the precise installation of this new venting to ensure it meets all manufacturer and local code requirements.

Finally, an electrical connection and a condensate drain are necessary. Navien tankless units require a dedicated 120V outlet to power the unit’s controls, fans, and pumps. As a condensing water heater, the unit also produces a small amount of acidic condensate that must be safely drained away. The installer will connect a drain line to a floor drain or condensate pump, ensuring proper disposal. A professional will assess your specific home layout to seamlessly integrate these requirements.

Can I Troubleshoot Common Issues After I Replace My Old Water Heater with Navien Tankless?

Once your new Navien system is installed, it is generally maintenance-free. However, understanding a few potential issues can be helpful.

“The hot water is taking a long time to reach my faucet.” This is a common question, especially for those accustomed to a tank system. The “cold water sandwich” effect or a longer wait time for hot water is often a function of the distance between the tankless unit and the fixture. Unlike a tank that holds a large volume of hot water, the tankless unit must heat water from a cold state and send it through the pipes. The solution for this is often to install a recirculation system, which keeps hot water circulating through the pipes and provides near-instantaneous hot water at the tap.

“My hot water flow seems lower than before.” This can be caused by several factors. A common issue is debris or sediment buildup in the cold water inlet filter, which can restrict flow. The filter should be checked and cleaned periodically. If the problem persists, the unit may be undersized for your home’s hot water needs. The gallons per minute (GPM) rating of your unit should be sufficient to handle simultaneous hot water use. A plumber can evaluate your household’s demand and ensure the system is properly sized to avoid this issue.

“My Navien tankless water heater is showing an error code.” Error codes are a diagnostic tool, not a sign of a major breakdown. They can be triggered by low gas pressure, a dirty flame sensor, or a clogged air filter. The Navien owner’s manual provides a guide for common error codes. Always consult a professional for serious issues, as tampering with the unit could void the warranty and create a safety risk.

Making the decision to replace old water heater with Navien tankless is a smart investment in your home’s future. The combination of energy savings, endless hot water, and a longer lifespan makes the initial cost well worth it. With the right professional installation, you’ll be enjoying the modern convenience of a Navien tankless water heater for many years to come.