Disadvantages of Tankless Water Heater. Amidst the advantages of tankless water heaters, there are also disadvantages of this equipment.
Higher expenses paid. Talking with the average, tankless heaters cost more or less $500 higher that the tanked water heaters. Plus with the additional cost for ventilation, electrical outlets and gas lines, the price gets even higher. It didn’t stop there because one would still need to pay for the installation expenses. One will not just pay for a plumber since one would surely need to consult an electrician and a framer.
More energy used. Since tankless water heaters don’t need tank it must heat water abruptly. This means that it requires gas/electricity directly on the time of usage. This type of set up would require more energy than just pre-heating the water and store it for usage.
Cooler water poured out. When hot water is needed for two or more task, like doing the laundry and taking a bath, tankless water heater gives out cooler water than using hot water for one task at a time. Also, for cooler seasons, tankless water heater gives out cooler water than other seasons. Since tap water is colder in winter, much energy is required to heat the water up to 120 degrees. The tankless water heater cannot do this unless the flow rate is slowed down.
No hot water when the power is off. With the fact that the controller of the tankless water heater is electric, it needs a DC outlet to run. This means that when the power is off, there will be no supply for hot water.
Fewer years for unpure water. Unpure water contains minerals that evaporate when submitted to hot temperature. This would form residues at the side of the tube that leads to rusting of the tubes and even blocking water flow. Hence, yearly maintenance is absolutely recommended.
Greenhouse gases. Gas tankless water heaters emit gases that add up to the greenhouse gases. More wasted water. With the thought that there is unlimited supply of hot water, the one using would not mind using water on excess amount.