Sales of tankless water heaters recently boomed. Unlimited hot water and energy savings are the features most commonly reported by the tankless water heater industry, and they often mention a smaller footprint. They do provide an unlimited supply, but without their own problems.Check out this website for more info.
Water heaters of storage form have been the norm in the U.S. but recently tankless water heaters have started to make an impact. Many people are familiar with water heaters for storage (type of tank), where you have a large tank of heated water ready to use and wait when you need it. Gas flames, electric heating elements, or any other method can heat the water. Tank or tank style heaters have two potential problems, the first is that they use more standby energy than tankless water heaters and the second is that heated water will run out of them.
Tankless water heaters also have other disadvantages about them. For one thing, when sufficient flow is detected, tankless water heaters have a flow switch in the water line which turns them on. Normally for turning on the machine a flow of about 1⁄2 gallon per minute or more is needed. It virtually eliminates the possibility for anything to have access to a low-flow current.
Filling a bath with a tankless unit can sometimes be difficult. In tankless heaters, the higher the water flow rate, the lower the temperature rise, as the water is spending less time in the heater. Typically you turn on the water full blast with a bathtub, so it doesn’t take too long to fill the tub. The faucet at the tub would usually have the highest flow rate of any device in your house, sometimes 7 gallons per minute or longer. For traditional tankless heaters you end up with a tepid-water pool. If you’re trying to fill it up more slowly to get it cooler it will take so long to top it off before you get in anyway. So if you want to float away in a hot tub, it’s better to make sure you get a large enough heater to do the job.
Tankless heaters are substantially more expensive than storage heaters, and more complex, so if anything goes wrong they are more expensive to repair. They also need larger flues, and often require special extra heavy wiring if they are electric.
Another problem with tankless systems is that they take longer to get hot water to the attachments. Which means you are wasting more energy, which is not very pleasant to the climate. The reason is that the flow switch turns on the heater when you turn the hot water on, and it starts heating up the water. But in order to reach maximum temperature the water has to pass through the whole heater. Now you have to dump in the hot water piping not only the cooled off water, but also the cooled off water in the water heater before getting hot water at the fixture.
Circulating systems do not work with tankless heaters because either the hot water flow will not be sufficient to turn the heater on, or it will keep the heater turned on all the time. Neither scenario is working. There is however a way to solve the long-waited and wasted water issues.
A demand system will work with water heaters of the tankless and storage type, providing the benefits of faster delivery of hot water and eliminating water running down the drain.
The demand hot water pump installs from the heater at the furthest fixture, and connects with the hot and cold water lines. When you want hot water, you press a button and the cooled hot water in the hot water piping is pumped back to the heater’s inlet, and the pump shuts off when the actual hot water reaches the fixture. That way you get your hot water faster than running the faucet, you’re not running any water down the drain while you’re waiting, and you’re not filling the hot water line. You’re saving on time, water and money. For a family of four, typical savings can amount to over 15,000 gallons per annum. Used with a tankless water heater, a hot water demand system makes a great environmentally friendly package, saving water and energy.
Demand systems work equally well with water heaters of the storage sort, and if you are considering such a system, you may be able to check with your water company as some offer rebates for such systems. Check that the pump is powerful enough to turn the flow switch on, since not all pumps are strong enough. Metlund manufactures a number of demand pump models, of which at least one will run a tankless heater. Chilipepper Sales also manufactures the Chilipepper appliance that has a pump that is strong enough to run any heater without tank.