4 Common Things to Check if Your Tankless Water Heater Stops Working

Many homeowners make the switch to a tankless water heater because it’s more energy efficient and it delivers hot water on-demand. These appliances are also easy to work on and this makes the ongoing maintenance costs lower than a traditional water heater. But, like any moderately complex appliance, there are times when a tankless heater may stop working. In this article, we will look at four common things that you can check if your tankless water heater stops working.

1.  There is No Hot Water

As you might imagine, if you cannot get hot water out of the tap, it’s a sure sign that something is wrong. Diagnosing the exact cause of the problem can be tricky because there are a number of things that may be wrong. To learn the root cause of the problem it’s necessary to answer a few questions, they are:

How Many Appliances are You Running?

Under normal operating conditions, it should be possible to get hot water to your taps or appliances or other plumbing fixtures. But, if you are running multiple appliances at the same time, the problem could be that demand is outstripping supply. A typical scenario would be someone taking a shower as the washer and dishwasher are running. Experimenting with the activity taking place as you use the hot water should help you to identify and isolate these types of problems. In many cases, some basic schedule and lifestyle changes will prevent this problem from occurring when you least expect it. To fix the problem, prioritize the hot water that you need right now, turn off the others and then restart your tankless water heater.

Is There a Clogging Issue?

When any air take channel, vent or duct is blocked, it can lead to a number of problems including the supply of hot water. One of the best things about modern tankless water heaters is that they have built-in notification systems. If there is a blockage, you will get an automatic alert that the exhaust vent needs to be cleared. It’s important to keep the areas outside and inside free from debris and dust bunnies are a common problem. Another possible cause is dirty burners, they need to be kept clean to work efficiently.

Are You Asking for Too Little Hot Water?

After the answer to the previous question, this may seem strange, but it is possible to call for too little hot water and this can affect the performance. Each tankless hot water heater has a minimum flow rate expressed in gallons per minute (gpm). The minimum flow rate must be reached or the unit may shut-off and this is a deliberate and built-in safety measure. This may occur if the tap or shower head is only partially opened. The easiest way to deal with this problem is to increase the hot water flow and check if the water heats up as intended.

Are the Pipes Frozen?

When the weather turns colder any exposed pipes can be prone to freezing. If a water pipe near the tankless water heater is frozen this will prevent the hot water from traveling through the pipes. The best way to deal with this problem is to slowly and naturally thaw the pipes before you try and get any more hot water. To prevent future pipe freezes consider installation for the pipes.

Does the Water Heater Have Power?

The tankless water needs power to work and if there is no power it shouldn’t be surprising that there is no hot water. If the water heater runs on electricity, the first step should be to check the electrical panel. A power surge may have caused the breaker to trip and this will need to be reset before you can restart the tankless water heater. If your appliance runs on gas, check the gas valve to ensure that it’s in the “On” position and if you have a propane tank, make sure that it’s not empty. If these solutions don’t fix the problem, it’s time to contact your local professional plumber or gas supplier for expert help and advice.

2.  The Water Quality Has Changed

If your water quality has changed drastically the problem may be related to your tankless water heater. The water that comes from your taps should be clear and clean and any signs of discoloration or bad smells are a sure sign that something is wrong. Many homes receive hard water which has an elevated level of dissolved mineral content that can accumulate inside the appliance. Gradually the water can become cloudy or it may change to a brown or yellow color. Another common problem is the growth of bacteria inside the appliance which can ruin the quality of your water. The best way to avoid or fix these problems is to schedule some regular maintenance and periodic flushing with a descaling solution can help.

3.  The Water is Too Hot

If the water is too hot, there are a few possible causes to investigate before you call a professional plumber. Check the water heater thermostat and make sure it’s set at around 120ºF. If the temperature sensor is inaccurate, it can be improved with repositioning. If the system is overloaded, it can cause temperature fluctuations and it’s a great idea to limit activities to 2-3 fixtures or appliances. Another common cause is blockages as discussed earlier, a reduction in water flow can overheat the water.

4.  The Water Runs Too Hot and Then Too Cold and Back Again

This is as annoying as it sounds, the water gets hotter, colder and the cycle repeats. As you might imagine, this is most noticeable when you take a shower and typically occurs when someone took a shower just before you did. Essentially, you’re getting the leftover water that was heated or from the previous user and the water goes cold as the water heater reheats the water. If this is a common phenomenon, it can ruin your showering experience and it may be a good idea to install a mini tankless water heater dedicated to the shower. This will even out the temperature variances and it’s an effective solution for a busier home.

If you have any problems with your tankless water heater, contact your local professional plumber today.