There are countless benefits associated with installing a tankless water heater, apart from being touted as a safer option over storage tank heaters. Despite this, tankless heaters are not devoid of hazards.
Tankless water heaters, especially electric ones, can’t explode. considering that there is no tank that could house perilous pressure buildup or experience overheating. Nevertheless, they’re still susceptible to dangerous carbon monoxide leaks and, in more rare cases, catching fire.

The chances of a tankless heater catching fire are minimal when we take into account that they only heat water on demand. Regardless, depending on the energy source used – whether it be gas or electricity – a fire can be triggered by many different events, such as a gas leak or an electrical spark, respectively.
Still, the risks of using a traditional water heater are far higher and the variables that could prompt possible bursts and fires are much more numerous, with correspondingly onerous consequences.
Moreover, most modern tankless water heaters come equipped with built-in safety mechanisms aimed at stopping the appliance from operating under certain conditions related to overheating. You will notice issues with your heater whenever you discover that the water is not coming out hot and a beep is heard from the device, in which case it has stopped working, most likely, because a vulnerability was identified and the security feature was, thus, activated.
When using gas tankless heaters, you should watch out for potential gas leaks. It’s one of the main causes of explosions in homes and even entire blocks.
These leaks are, in various instances, easy to detect, but, depending on the gas supply, these flammable vapors could be imperceptible (particularly odorless gas) which is why you should be mindful of hissing sounds coming from around the heater, or to other warning signs such as a persistent headache. As a general rule, It’s always important to install these systems in relatively ventilated areas where gases may be able to escape, avoiding dangerous gas accumulations.
When it comes to gas-fueled heaters, we ought to pay attention to their specifications and manufacturing year. Newer heaters are less prone to catching fire than older ones, in great part because the newer ones have a sealed bottom that isolates the ignition flame from the gas suspended on the outside. Having this seal effectively thwarts any chance of fire from the heater getting in direct contact with the flammable gas.

Electric heaters, conversely are much less probable to catch fire. Unless the heater is badly built or installed, the safety of electric water heaters far surpasses that of a gas heater, mainly owing to the fact that they don’t rely on combustible gas and there is, consequently, no ignition flame that could be fed and driven out of control.
Even with that said, it’s always recommended that you perform periodic checks on the heater system to make sure there are no damages to its internal components. There is always a degree of risk involved, markedly in the case of gas-powered systems.
Also, you should strive to err on the safe side and keep your heater away from flammable chemicals and cleaning products.