Top 7 Reasons Why Your Tankless Water Heater Isn't Working

Even though they are not in use as much as other water heaters, you might still encounter problems with a tankless water heater. If your gas or electric tankless water heater is not working, we have compiled a list of seven common problems along with troubleshooting steps to restore warm water in your house

1. Tankless Water Heater Not Powering On

If you notice a strange smell or see discolored water coming from your sink, it's possible that something is growing inside the water heater. However, there's no need to panic as minerals often accumulate in tankless systems. One simple solution to this problem is to flush out excess magnesium and calcium from your system. Mineral buildup can lead to discolored water and odors. To prevent this, it's recommended to flush the heater at least once every six months. You can use a descaling solution or vinegar to flush out these minerals.

2. Unpleasant Odor or Discolored Water

If you smell something strange or see discolored water coming from the sink, something might be growing inside the water heater. This is no cause for alarm, though—minerals get in tankless systems all the time. An easy way to fix this tankless water heater problem is to flush excess magnesium and calcium out of your system. A buildup of minerals in your system can cause discolored water and odors. To help prevent buildup, flush the heater at least once every six months. A descaling solution or vinegar can be used to flush the water heater of those minerals.

3. “No Ignition” Error

If you see a message on the display that says "no ignition," it could indicate one of two things. Either the gas supply is low, or the valves for the gas or water are closed, preventing the flame from igniting. If your tankless water heater is not functioning, check if the ignition pack is working properly and ensure that there is enough gas in the propane tank. If that's not the issue, make sure that all valves are open so that gas can ignite the flame.

4. Flame Failure

If you see a "flame failure" message on the display, it means that something is preventing the flame in the water heater from staying lit. This could be due to closed valves that are not supplying gas or a blocked ventilation system. Just like the "no ignition" error, make sure that the gas, propane, and water valves are all open. Then, check that there are no obstructions in the vents leading to and from the heater.

5. Exhaust Blockage

When your tankless water heater is not working, it could be a sign of a blocked exhaust system. A tankless system requires access to fresh air in order to properly vent outdoors while in use. To check for a blocked exhaust system, start by ensuring that the exhaust pipe is clear and open. Next, inspect the vents both inside and outside your home to make sure they are free from any objects. While doing this, also check for any holes in the pipes. Lastly, verify that the system was installed correctly and not placed too close to other objects, as this can cause a blockage.

6. Temperature Fluctuations

Experiencing alternating hot and cold water while the tap is on can be frustrating, but the cause is usually simple. This issue with tankless water heaters is often caused by residual hot water remaining in the pipes from the previous use. Be patient, as your tankless system needs to start heating again in order to provide you with a continuous supply of hot water. Once it is heated, you should have hot water for as long as you need it.

7. System Overload

If the temperature of the water in your home keeps fluctuating, it may be a sign that your tankless water heater is overloaded. This can result in insufficient hot water or the heater not working at all. In such cases, the system may shut down when you need warm water. To resolve this issue, try resetting the water heater by turning off any extra taps and only running one until the hot water returns. If this problem persists on a daily basis, you may need to consider alternative options such as a larger system or replacing the heater altogether.

Advantages of a Tankless Water Heater

Unlike traditional water heaters that constantly keep the water in the tank hot, tankless water heaters only heat the water when you turn on the tap. This energy-saving feature can help you save money and avoid costly repairs and maintenance in the future. Additionally, using your system less frequently can extend its lifespan.