A water heater may sound a beep to warn that there is a water leak. Leaks may be obvious if the floor is wet near the water heater, but the leak might also be somewhere along the line. The beeping may be initiated by a water heater shutoff feature, a flood prevention device. Beeping may also signal a gas leak.Click to see full answer. Keeping this in view, how do you reset a tankless water heater?You may easily reset the electric reset button by pressing the red button. Some unit comes with the lower thermostat reset button. In this situation, you need to push the reset button too. When you push the buttons, but they don’t reset instantly, some parts of the water heater may cause the problem.Furthermore, do tankless water heaters need to be flushed? Tankless water heater manufacturers recommend their units be flushed at least once a year to eliminate the buildup of calcium and other minerals within the unit — even more often if you have hard water. Some units will indicate when the unit is in need of flushing. Just so, what are the disadvantages of a tankless water heater? The primary disadvantage of on demand or instant hot water heaters is the upfront cost. The smaller units that you often see won’t produce enough hot water to serve most households. They’ll only serve one faucet at a time—a problem if you want to shower while the dishwasher is running.Why is my heater beeping?Any time you notice a frequent beeping noise coming from the furnace, this means something isn’t right and the system is alerting you to an issue. Some furnaces will beep when the air filter needs to be changed. Always refer to the owner’s manual to see what a beeping sound means for your specific heating system.