Getting a blast of cold water in the middle of a relaxing shower is an uncomfortable surprise, to say the least. It’s a common dilemma for those with tankless water heaters—the unit that’s supposed to provide limitless hot water starts misbehaving.
For the uninitiated, tankless water heaters, also known as on-demand water heaters, are popular due to their space-saving design and energy efficiency. But when they start acting up, understanding why is the key to a quick fix.
In this comprehensive look at tankless water heater issues, we’ll address the most common hiccups, how to troubleshoot them when to call in the professionals, and preventative maintenance that could save you from future shivers. Whether you’re a DIY enthusiast, an energy-conscious homeowner, or a new tankless heater owner, this article has you covered.
Common Causes of Tankless Water Heater Issues
Before we start flipping switches and tightening bolts, let’s examine why your tankless water heater may be underperforming.
Insufficient Gas Supply
Tankless water heaters typically run on natural gas or propane. If there’s a problem with the gas supply, your heater won’t be able to function at full capacity. Check to ensure that the gas valve is fully open and that there is no interruption in the gas supply to your unit.
Mineral Buildup in the Heat Exchanger
Water that’s high in mineral content can cause scaling in the heat exchanger, which leads to decreased efficiency and ultimately, a lack of hot water. Regular maintenance to descale your water heater is essential, but if the problem persists, a more thorough cleaning may be necessary.
Improper Venting
The ventilation system in tankless water heaters is critical for safe operation. If there’s a blockage, the unit may shut off due to a lack of air or to prevent carbon monoxide buildup. Inspect the venting system for any obstruction and ensure it’s properly installed according to the manufacturer’s guidelines.
Incorrect Temperature Settings
Sometimes the solution is simpler than expected. If the heater is set too low or too high, it won’t meet the demand for hot water. Follow your unit’s manual to verify the temperature settings and adjust as needed.
Troubleshooting Steps
Now that we have an idea of what might be wrong, let’s go through some troubleshooting steps you can take to address these issues.
Check Gas Supply and Pressure
Start by turning off all the hot water taps and checking the gas supply. If you have a natural gas unit, the valve should be parallel to the line when it’s open.
For propane, it’s typical to have a pressure gauge that should read within the correct range. If you’re unsure, contacting your gas supplier may be your best initial step. A pressure gauge can indicate if the supply is adequate for the heater.
Flush the Heat Exchanger
Scaling of the heat exchangers can be significant in hard water areas, and a thorough flush may be needed.
Turn off the power and water supply, then use a pump and a descaling solution to remove the mineral buildup. Be cautious, as the process may require some disassembly of the unit.
Ensure Proper Venting
Examine the venting system carefully. Make sure that all joints are sealed and that nothing is obstructing the flow.
A common issue is insects building nests in the vent, or the vent could have been damaged. An intact, clear vent is crucial for proper tankless water heater operation.
Adjust Temperature Settings
Temperature is the primary reason for inconsistency in hot water delivery. Readjusting the temperature to have a water heater’s output of 120 degrees Fahrenheit is generally recommended but consult your user manual for the ideal temperature range for your model.
When to Call a Professional Plumber
Not all tankless water heater issues are DIY-appropriate. If the problem seems beyond the initial troubleshooting, it may be time to call in a professional plumber.
Some issues you don’t want to tackle on your own include dealing with gas lines, venting issues that require roofing skills, or when the unit is still under warranty.
Complex Issues Requiring Expertise
If you aren’t comfortable working with gas lines or if you suspect a complex internal mechanical issue, it’s best to leave it to a professional. They’ll have the tools and knowledge to diagnose and fix more serious problems.
Warranty Considerations
Most tankless water heaters come with warranties that could be void if you tamper with the unit without proper authorization. Professional plumbers will work within the guidelines of the warranty to protect you from unexpected costs.
Preventive Maintenance Tips
One way to avoid a full-blown tankless water heater crisis is by regularly maintaining it. Here are some maintenance tips to keep your heater running smoothly.
Regular Descaling
Scaling is the number one enemy of tankless water heaters. Regularly descaling the heat exchanger can prevent mineral buildup and keep your water heater operating at maximum efficiency. Your unit’s manual should outline a descaling schedule.
Flushing the System
Another helpful preventive measure is flushing the entire system at least once a year. This can help remove any sediment in the water lines and would provide an opportunity to check for scaling and the integrity of the unit’s components.
Monitoring Gas Supply
Keep an eye on your gas supply system. If you have high gas usage and you start seeing problems with any gas appliance, it’s good to check with a gas professional. They can detect leaks or low gas pressure that could be affecting your tankless water heater.
Final Thoughts
Experiencing a drop in tankless water heater performance is inconvenient. But with a methodical approach to troubleshooting, there’s a good chance you can understand and remedy the issue. Remember, regular maintenance and knowing when to call a professional are key to the reliable and long-term operation of your tankless water heater. Save yourself from shivers and enjoy endless hot water by following these practical tips and taking the necessary precautions.