It costs about $2,216 on average for a brand-new tankless water heater. That doesn’t include installation which costs about $2,800 more depending on the brand.

If you’re having tankless water heater problems, it’s easy to stress out over the thought of a complete replacement. Fortunately, many issues are fixable if you know what to look for and can save you a bundle.

The following guide will explore common tankless water heater issues and what to do about them.

High Tankless Water Heater Temperature

If your water is coming out too hot, the fix might be as easy as adjusting the temperature setting. Sometimes the temperature sensor or output sensor gets out of place or broken and requires maintenance or replacement. 

A tankless water heater blockage might also be the culprit. Obstructions cause heat to build up and your water to become hotter than desired.

You might need a tankless water heater reset if too much sediment builds up. It involves flushing and descaling the heater, which often resolves temperature issues.

The issue might not be with the heater, but with clogs in pipes or showerheads in some cases. It hurts the flow of water causing only a small amount to get heated to a high temperature.

Regular tankless water heater maintenance is the best way to prevent temperature issues. This particular issue usually won’t require an extensive water heater repair job.

No Heated Water

Lack of hot water is the most prevalent problem with tankless water heaters. It usually has to do with the power supply or water supply rather than with the unit itself. Check out your electric or gas supply for issues and also the water shut-off valve.

Your tap from the shut-off valve must stay open enough to let water flow properly. If it’s open and still not flowing enough, you might have a blockage in your pipes.

Make sure that the flame of your gas burner makes a spark and clean or replace it if it doesn’t. For electric heaters, check the circuit breaker problems. You should also pay attention to any error codes displayed on the heater’s control panel.

Low Water Heater Pressure

First, make sure your heater has the ability to provide adequate pressure to your entire home. In other words, your home might be too large for your water heater to keep up.

Also, make sure you aren’t running too many appliances at the same time. For example, the pressure might be low if you’re running the dishwasher and washing machine while showering at the same time.

Just like with temperature issues, make sure you don’t have any blockages in your pipes that might lower the pressure.

Strange or Loud Noises

A dirty fan often causes tankless heaters to make loud noises. Clean your fan regularly to prevent this common issue.

Burner flames in noisy units might not have enough stability. It’s usually because due to a lack of gas pressure and combustion air.

Unstable gas combustion tends to occur if you have any leaks in the sealed combustion chamber. Also, make sure you see a blue flame rather than a yellow flame when your burner burns gas.

The Burner Won’t Ignite

If your burner won’t ignite, make sure that gas, water, and electricity are turned on and clear of blockages. Take a look at your circuit breaker if you use an electric heater.

Try clearing any air out of the gas line and make sure the system’s vent was installed correctly. Check the unit’s flame rod and wiring harness for any damage, loose connections, or other issues.

Sometimes burners won’t ignite if the flow sensor isn’t working properly. You also need to double-check that you’re using the right type of gas and pressure for the unit.

Plumbing Crossover Issues

A home’s plumbing system has two sub-systems for hot and cold water. A plumbing crossover occurs when cold water flows into the hot water system. 

To test for a plumbing crossover, start by shutting off the inlet valve for cold water. Then, open every hot water faucet in your house.

Wait about 10 minutes to see if there’s any water flow. If you see water flow, that means you have a plumbing crossover.

Temperature Fluctuations

Have you ever been taking a hot shower when a burst of cold water hits you out of nowhere? It’s probably because you were using leftover heated water and the new water didn’t heat fast enough. 

If you have a long pipe distance from the heater to your shower, that might be part of the problem. It might also have to do with your gas line being the wrong size. The length of the venting pipe might also affect random temperature changes.

You could have a flow sensor that isn’t working and needs a replacement. The cold water inlet might also need cleaning because sometimes they get covered in dirt.

Frequent Error Codes

You’ll probably see an error code displayed if your water flow sensor becomes blocked. Errors pop up when your unit determines there isn’t adequate water flow.

It also commonly displays errors if the gas pressure is too high or low. If the pressure is too low, you mike have a gas leak causing the problem.

Correcting Tankless Water Heater Problems

Now you know the most common tankless water heater problems and the solutions. While some of the issues mentioned might require professional repairs, it’s rare to need a complete replacement.

So, keep this guide in mind, and don’t panic if your tankless heater acts up! Take a look at our site’s home and garden section for more ways to improve your living spaces.

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