Signs of a Broken Tankless Water Heater Heat Exchanger

Tankless water heaters are complex machines, and that complexity can make it difficult to tell what your issue is when they break down. The heat exchanger is one of the key components in a tankless water heater, but how can you tell when your heat exchanger is having issues?

After 20 years of servicing tankless water heaters, we know just what to look for when it comes to busted heat exchangers. While the signs are obvious once you know what to look for, this issue has left many homeowners scratching their heads, frustrated, or, more likely, both.

In this article, we’ll fill you in on what a heat exchanger is, what to look for when one breaks, and the immediate steps you should take if you notice any of the symptoms.

Before we dive in, let’s take a broad look at some of the potential signs of a broken tankless water heater heat exchanger, which include the following:

Let’s get the ball rolling with a quick rundown of what a heat exchanger is.

What Is a Heat Exchanger?

The heat exchanger is often referred to as the core of a tankless water heater. They come in either stainless steel or copper variants, each with its own pros and cons. But regardless of which style of heat exchanger you have, their functionality is the same. Heat exchangers are responsible for heating the water that enters your home. They operate with the help of two other smaller components.

When you run the faucet or any other water fixture, the flow sensor tells the igniter flame to kick on, which then heats the coils of the heat exchanger that contain the running water. The igniter flame heats the water to the preset temperature, and the hot water flows to the fixture, creating the demand.

But how can you tell when a heat exchanger isn’t working correctly?

Signs of a Broken Tankless Water Heater Heat Exchanger

There are a couple of signs that will tip you off that your heat exchanger needs some attention. While some are more obvious than others, none are difficult to spot. After this section, you’ll be able to make a well-educated guess as to whether something is up with your tankless water heater’s heat exchanger.

No Hot Water or Intermittent Hot Water

If your hot water cuts out intermittently or altogether, it’s likely there is an issue with your heat exchanger. This is your first big tip-off that something isn’t quite right with your heat exchanger.

You can always go take a look at the unit itself to further diagnose the issue. But calling a technician out to get your tankless water heater heat exchanger patched up is the best course of action unless you have prior experience.

Leaking

Once you’re looking at your tankless water heater, the next thing you can do to troubleshoot the issue is to check for any visible leaks. If you find a leak or pooling on the floor, be sure to shut off your tankless water heater to prevent further damage.

Shutting off your tankless water heater will prevent further damage and is the first step to success when attempting to preserve the unit.

Visible Water Damage

Water damage isn’t limited to visible leaks outside of the tankless water heater. Instead of calling it quits when you see a visible leak or pooling, it’s worth opening up the unit and checking for issues inside.

You’ll want to check for any water damage, like rust or other types of corrosion. If you see any signs of water damage, turn off the tankless water heater to help preserve it.

Escaping Steam

Here’s one that will be immediately apparent once you’ve got eyes on your tankless water heater. If steam is escaping from the venting, it could signal that there is water in the heat exchanger, indicating a pinhole leak.

If you experience this issue, unplug the unit, turn off the gas and water, and call a technician.

Gas Smell

If you check up on your tankless water heater and smell gas, the first thing you need to do is turn off the gas and ventilate the room. This issue means your tankless water heater isn’t firing at all.

Like many of the issues listed here, there are multiple causes for this kind of issue, which we’ll discuss in the next section.

Error Codes on Remote

Lastly, if you encounter error codes on your remote, it’s worth checking your owner’s manual or the manufacturer’s website to see what the error code corresponds with. While there are many error codes, consulting your tankless water heater’s documentation will provide more clarity as to what’s going on with your unit.

What Causes Issues with Tankless Water Heater Heat Exchangers?

There are plenty of reasons a tankless water heater heat exchanger would break down. But there are a few common reasons that tend to be the case more than others. Let’s check out a few of these causes.

Lack of Maintenance

Tankless water heaters generally require annual maintenance to keep them running smoothly. If you skimp on maintenance for an extended period, especially in areas with hard water, you run the risk of damaging your heat exchanger.

No Water Treatment

This cause is a big one for hard water areas. It is a downright necessity to have water treatment installed with your tankless in a hard water area. Without water treatment, your tankless water heater could face premature breakdowns and corrosion-related issues, as we talked about above.

Improper Installation

Now, this one is a wide-reaching issue. Improper installation can mean any number of things. From installing the wrong size gas line to botching the venting job, there are quite a few things that can go wrong and cause damage to your heat exchanger.

But what do you do when you encounter these issues?

What to Do When You Experience Issues with Your Tankless Water Heater Heat Exchanger

The following is the best practice for any of the situations we’ve described so far. Your first step in any of these scenarios is to unplug the tankless water heater and shut off the gas and water.

Following these steps will ensure your safety while you get in touch with a technician. Schedule an appointment to have an inspection and go from there.

An important note to take down is that you can’t repair a heat exchanger. You can only replace tankless water heater heat exchangers, so double-check your warranty terms ahead of your inspection to avoid surprises. In terms of cost, this will vary depending on your specific tankless water heater model.

Is Your Heat Exchanger on the Fritz?

We’ve touched on how to tell when your tankless water heater heat exchanger is broken down, as well as what causes these issues and what to do when you experience them. Now, you’ll be able to spot the issue from a mile away and communicate more effectively with the call center or technician when you call in for help.

We understand that life without hot water is frustrating and can drastically alter your plans. That’s why we’ve made hundreds of emergency calls to get families back on track with their day.

If you need a hand with your tankless water heater heat exchanger and live in Los Angeles County or the surrounding area, give us a call at (818) 213-1773 or visit our Tankless Water Heaters page to book online.

If you want to look into different types of tankless water heater maintenance or get a better understanding of why water treatment is important, it’s always advisable to do a bit more research. Additionally, if you have a hunch something isn’t quite right with your tankless water heater, check out the top ways they can be installed incorrectly.

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