Common Tankless Water Heater Problems

Solve the Most Common Problems Water Heaters Without Tanks

Many modern Arizona homes have tankless heaters. The ease of use, speed, and convenience they offer have made them popular. Additionally, the technology enables homeowners to be more energy- and water-efficient. Even so, tankless heaters are just like any home appliance, and can be prone to malfunction.

Precision Air & Plumbing has a keen understanding of how tankless heaters work, so we’ve shared a guide to help you fix the most common issues with this system. Read on to see what you can do. If the problem keeps happening, then we’re here to offer professional help.

Problem 1: The Temperature Keeps Fluctuating

You’re mindlessly soaping up under the warm water during a winter morning when, suddenly, the temperature drops to near freezing. Not only is this issue uncomfortable, but it’s also inconvenient. You’ll need to wait for a few minutes before you can resume your regular shower.

Fluctuating temperatures can be caused by a few underlying issues. Here’s how you can solve it.

1. Adjust Temperature Settings: The first step is to check the temperature. Many heaters come with preset temperatures, and adjustments are needed to ensure the water reaches your preferred levels.
2. Check the Flow: Another common cause for unstable temperature is irregular flow. Fluctuations can make it harder for the unit to maintain a consistent temperature. To address this, check for blockages or obstructions that could be affecting intake.
3. Keep the Heat Exchanger in Good Condition: The heat exchanger is the component that transfers heat to the flowing water. Regular maintenance, such as descaling and flushing, helps prevent mineral deposits from causing issues with the heating system. Keep in mind that even a small layer of scale can reduce the heating efficiency by a lot. A deposit-free heat exchanger ensures consistent flow and temperature.

Problem 2: The Tankless Heater Isn’t Heating 

It’s one thing to have fluctuating temperatures. What if the water doesn’t get hot at all? This issue can feel frustrating because tankless heaters are a major expense for the sake of comfort. Imagine waking up for work on chilly Phoenix mornings, only to have no water ready for a warm shower. Aside from checking whether the heater is plugged in, what can you do to solve this issue?

1. Check Supply: The most common cause of unheated water is a disrupted supply. Closed valves, damaged pipes, and other blockages can result in the heater not producing enough hot water. As such, you’ll want to check the connections of your unit to see if they are properly connected and functioning.
2. See the Gas Connection: Another common cause of cold water from the heater is a disconnected gas supply. Most tankless heaters rely on your gas supply to heat the system, so any disruptions could lead to inefficiency or total malfunction. Check for closed valves and damaged piping. If you suspect a gas leak, don’t try to fix it yourself! Contact a professional to address the problem quickly and safely.
3. Flush the Entire Unit: Mineral buildup will also result in a lack of hot water. At first, the temperatures will fluctuate. However, if left unchecked, the scales will result in total inefficiency. Tankless heaters include instructions in the manual for performing a system flush. Taking this step helps you remove mineral deposits and sediment, restoring your unit’s water heating efficiency.

Problem 3: The Heater Stops Working When I Shower

The most concerning problem with a tankless heater is when it stops working altogether, leaving you in the cold with soap in your hair and on your body. Here are some of the things you can try if this issue keeps happening.

1. Inconsistent Pressures: Fluctuations in water pressure can cause the unit to shut off. This mechanism is critical to prevent damage from short cycling. As such, consistent pressure — one that meets the unit’s minimum threshold — is essential for proper functioning. The pressure should range from 30 to 80 psi. You’ll need to confirm that your unit can reach these numbers to ensure smooth operation.
2. Clogged Air Filters: To prevent dust from entering the unit, air filters are crucial. If these components are clogged or dirty, the heater may shut down as a safety precaution. Check your air filters and clean them periodically to guarantee that your heater will continue to work.
3. Overuse: High water use can lead to the unit shutting down because it cannot keep up. Average showers consume two to five gallons of water per minute. Beyond these limits, the heater turns off due to overuse. There are two ways you can remedy this issue. You can either reduce the water flow (while maintaining consistent pressure) or use showerheads with low-flow features to reduce the amount of water that flows out.

Trust an Expert Team To Solve Issues

Tankless heaters are handy and cost-effective additions to your home in Gilbert, Tempe, Scottsdale, Phoenix, Chandler or Queen Creek AZ, but they can still be prone to problems. If you encounter any of the issues we outlined above, try the solutions we shared to address them.

However, if the complications are far too complex for your skill level, then it’s time to contact the experts. Precision Air & Plumbing can thoroughly assess your unit and plumbing, allowing us to precisely diagnose the problem and provide the solutions you need. Contact us today to book an appointment!