Tankless water heaters, also known as Instant or Demand water heaters, heat water very quickly. However instantly heated hot water does not mean you will have hot water instantly at your sink or in your shower. You still need help delivering it.
Tankless water heaters heat water instantly. However unless you install one next to every sink, shower and appliance you will not get hot water instantly at the tap.
No matter how you heat the water, there is still cool water in the pipes between where you heated it and where you want to use it.
A plumber in Arizona recently told me that his company has installed over a thousand tankless water heaters in the last 3 years. He estimates that 60% of them are dissatisfied even though their energy bills are lower because they do not get hot water any faster than they did with their old tank style water heater.
Unless you have a hot water recirculation line your pipes are a dead end. There is no place for the water to go until you turn on a faucet. Then the cool water must leave the system before you get what you want – hot water. That can take a lot of time.
The reality is that if you had to wait 2 minutes for hot water before you installed the new heater, it will still be 2 minutes before you get hot water.
Tankless hot water heaters (also known as instantaneous or demand water heaters) can provide you with an unlimited amount of hot water under the right conditions and if they are maintained properly. They take up less space and they only run when you need hot water. All very good things.
But the wait for hot water cannot be resolved with a new energy efficient technology. The best solution is to install a recirc pump at the water heater and a bridge valve underneath the furthest sink between the hot and cold lines so that the pump can push the cool water in your hot water line back into the cold water line.
The pump should be activated by turning on a hot water faucet and it should be turned off when the faucet is turned off. Leaving a pump running full time or even part time when there is no water usage is not good for the water pipes or the pump.
If you are interested in saving money on your energy costs, tankless water heaters may be the way to go. But if you are trying to get hot water faster, you will need to do more than just heat it in a new way.
