Switching out your old tank-style water heater for a tankless version is a good way to save yourself some money and make your home more efficient. Just like regular water heaters, these units can also have problems on occasion. Look at a few of the more common issues that can come up and the likely causes.
The water heater seems to just shut down on a regular basis.
If you are using a lot of hot water and your tankless water heater just shuts down, it can definitely be frustrating to have to reset it constantly just to get the thing to work. This is perhaps one of the biggest complaints that new owners of a tankless unit have, but it is for a logical reason. If you have a small unit, it is only capable of supplying so many gallons of hot water on demand. If you are overloading the system by using a lot of hot water at once, some units are designed to automatically shut down to prevent damage to the unit. Therefore, this problem doesn't necessarily mean there is something wrong with the unit; rather, it is how you are using the unit.
The water heater is not distributing water as it should.
If you have been using your tankless water heater for a while and it suddenly stops dispersing water as it should, you could have a problem with mineral buildup inside the unit. Even though the tankless versions do not hold water, water is funneled through as it is heated. Therefore, the same issues you can have with mineral buildup in tank water heaters can also happen with tankless versions if they are not properly flushed periodically.
The water heater is showing you an error code because of exhaust problems.
Tankless water heaters that are fueled by some type of gas must have a ventilation or exhaust system to properly route fumes out of the house. If that exhaust system gets blocked, your tankless water heater may give you an error code on the digital screen. Some water heaters are designed to tell you what the problem is, but many units do not. Therefore, all you may know is wrong is that you are getting an error code and the unit won't work. In order to fix the problem, the exhaust will have to be cleared and the unit will have to be reset.
For more information, contact a water heater repair company.