Rogelio Alvarez

By: Rogelio Alvarez on May 1st, 2022

Print/Save as PDF

Top Issues With Tankless Water Heaters

Tankless Water Heaters

As efficient as tankless water heaters can be, they’re still prone to some issues. These issues don’t always occur, yet being aware of them can potentially help your tankless water heater go from fixable to full-on replacement. Some problems are more likely to occur than others, so it’s key to know what the top issues with tankless water heaters are so you can ensure you experience minimal inconveniences with your hot water. 

When it comes to tankless water heater issues, we at Monkey Wrench Plumbing, Heating & Air have spent the last 15 years servicing thousands of tankless water heaters throughout Los Angeles and the surrounding areas. From major to minor problems, our technicians have seen it all. Thanks to our experience, we know which issues occur the most and what steps homeowners can take to prepare for the worst.

The top issues commonly occurring with tankless water heaters are.

  • Error codes
  • Water leaks
  • Lack of hot water

The good news is that these concerns can be fixed, and knowing what these issues are beforehand can be the difference between a fixable solution and a complete tankless water heater replacement. Identifying these issues can save you hundreds to thousands of dollars. 

Now, let’s dive in!


What Are the Top Issues Seen With Tankless Water Heaters?

Tankless water heaters can last from 15 to over 25 years with proper care and maintenance, but they can likely experience a range of problems. Besides error codes, water leaks, and lack of hot water, limescale buildup from hard water can affect the performance of a tankless water heater or even cause irreversible damage. 

Scale buildup can cause a tankless water heater to use more energy to heat water, resulting in high utility bills and inefficient water heating. Homeowners can avoid scale buildup-related issues by installing a water-softening system. Water softeners prevent any scale from accumulating in a tankless water heater and can help extend its lifespan. 

A Monkey Wrench Plumbing, Heating & Air technician inspecting a water softener. Water softeners benefit tankless water heaters by combatting the effects of hard water. 

Another issue is having a tankless water heater with defective components that can render it inoperable. Thankfully, most manufacturers have warranties in place to help replace any faulty parts of tankless water heaters. So, if you see any of the following top issues, it’s best to call a technician to address these concerns and possibly review them for a warranty claim. 


Error Codes

Error codes are one of the most common issues that pop up on tankless water heaters. Luckily, these codes indicate some sort of problem with the tankless water heater that is entirely fixable. Still, it’s best to act fast and contact a technician immediately to prevent further damage to your tankless water heater or, worst-case scenario, pose a dangerous risk to you and your family. 

Each tankless water heater manufacturer, such as Navien, Takagi, and Noritz, has their own set of error codes that symbolize a specific issue with the water heater. Here’s a look at some common problems that can cause an error code to appear on your tankless water heater.

  • Heat exchanger issue
  • Ignition failure
  • Gas pressure problem
  • Issues with the flow sensor
  • Thermal fuse problem 

There are dozens of other error codes that can come up. A few of these error codes can go undetected if a homeowner doesn’t visually notice them appear on the tankless water heater display screen. Most of these codes, however, have symptoms that can range from no hot water to low water pressure. 

Most tankless water heaters have phone apps that notify homeowners of an error code so they can address it in a timely manner. Still, some tankless water heaters can experience issues without an error code appearing, such as a water leak. 


Water Leaks

Tankless water heaters can experience water leaks for various reasons but can easily be detected by the presence of water near the tankless water heater. Hard water, high water pressure, and a poorly installed tankless water heater can cause a leak to appear. For older tankless water heaters, any internal leaks could be caused by corroded parts, which can be replaced. 

Neglecting a leaking tankless water heater can lead to excessive water waste, and it can cause your water monthly water bill to increase. If you notice water leaking, the best thing to do is contact a technician. Water leaks from tankless water heaters can be fixed once the root cause of the issue is diagnosed and repaired. 

The following top issue seen with tankless water heaters is easy to notice but just as annoying for homeowners to deal with: a lack of hot water.


Lack of Hot Water 

The sole purpose of tankless water heaters is to provide hot water for a home. Although uncommon, tankless water heaters can fail to provide hot water for various reasons. Here are a few reasons why a tankless water heater may be unable to provide hot water.

  • Insufficient gas or electrical supply: Tankless water heaters rely on electricity, natural gas, or both to heat water. If there’s a power outage or a gas shutoff, tankless water heaters cannot heat water at all. 
  • Overheating safety feature: As a safety precaution, tankless water heaters have sensors that can reduce hot water temperatures if overheating is detected.
  • Bad heat exchanger: A heat exchanger is one of the main components that heat water. Any issues with the heat exchanger will render it inoperable to heat water and unable to provide hot water to a home. 

Homeowners can quickly tell when there’s a lack of hot water in their fixtures. Luckily, a lack of hot water is one of the most common reasons technicians are called out for tankless water heater inspections. If you find your tankless water heater isn’t able to provide hot water, it’s recommended to contact a technician immediately. 

A Monkey Wrench Plumbing, Heating & Air technician using a diagnostic tool to inspect a tankless water heater.


How to Avoid Tankless Water Heater Issues?

The best way to stay on top of tankless water heaters is to have annual inspections and maintenance done. Now that you know the top issues with tankless water heaters, you can take the necessary steps to take care of them promptly. 

Since 2007, we’ve helped homeowners in Los Angeles and the surrounding areas with servicing and repairing tankless water heaters. After fixing thousands of tankless water heaters, we created this article to bring awareness to the top issues with tankless water heaters so homeowners can be prepared for unexpected problems. 

If you’re experiencing any of these issues or have questions regarding tankless water heaters, contact us using one of the buttons below. You can also directly book an appointment through our tankless repair online scheduler

Whether you’re currently experiencing tankless water heater issues or not, it’s best to stay prepared by learning how much it costs to repair a tankless water heater. By understanding the costs, you can prepare a budget in case of a tankless water heater emergency.