An inline water heater can be a great thing to have. You get hot water almost immediately, and it doesn't run out. If you like to take long, hot showers, it can make a lot of sense for you to get one of these water heaters. However, like any other piece of mechanical equipment, sometimes your inline water heater is going to break down. That means that you aren't going to have hot water, or you will have hot water for a minute or two and then the water will turn very cold. When your water heater stops working, you want to do what you can to get your hot water back. There are some things that you can do to troubleshoot the water heater while you are waiting for the plumber to fix it for you.
Check the Exhaust
One thing you can do is to check the exhaust vent on the water heater and the one outside your house. If the exhaust port and vent get blocked, that can cause the water heater to shut down so that it doesn't get damaged. You may end up with a minute or two of hot water before it shuts itself down. The exterior vent for your inline water heater should be on the side of your house right by where the water heater is. Find the vent and make sure that nothing is blocking it. It's pretty easy to do, just brush off anything you see. Checking the interior port can be harder, because you may have to remove the cover of the unit, which may be something that you might not be comfortable doing. Look to see if you can see the exhaust port and then clean it off.
Turn It Off and Back On
Another thing that you can do is to turn the power off and then back on. That can reset the water heater and get it working again. If the unit is plugged into the wall, just unplug it from the wall for a few moments and plug it back in. If it is hardwired to your house, then you will need to go to the circuit breaker and either turn off that particular circuit or kill power to the entire house. Leave the power off for a moment or two, and then turn it back on. Try your hot water to see if that got it working.
If you have an inline water heater that has stopped working, you should call a plumber to have them check it out as soon as possible. There are things that you can do that will narrow down the problem before the plumber gets there.
Contact a local plumber to learn more about water heaters.