Every homeowner will face this question when the water heater eventually ages and fails: Should I go tankless?
In this How To Plumbing series post we take a look at tankless, or demand, water heaters. With apologies to The Clash, Should I stay (with a tank-storage water heater) or should I go (tankless)?
Tankless or Demand Water Heaters
Tankless water heaters are a great alternative to traditional tank water heaters.
- They provide unlimited, continuous hot water and eliminate wasteful reheating of hot water stored in a tank.
- Tankless water heaters require less space, less service and less energy than old style tank water heaters.
- A tankless unit can be installed as a replacement to an old tank water heater and — in most cases — can be easily installed as a part of a remodel or in new construction. Note the words: remodel and new construction.
- If you plan to swap a tank for tankless water heater in your home’s current energy infrastructure, it may or may not accommodate. Check with a Staten Island plumber or plumbing contractor/water heater specialist because retrofitting your home’s gas/electric may be needed, which can add considerable cost to the conversion.
Whether you are considering a tankless water heater to reduce your utility bills, for environmental concerns, to provide more hot water for your family, or you just want to enjoy long, long, luxurious hot showers, a tankless water heater may be right for you.
Again, before you get all excited about going tankless, check with a Staten Island plumber.
How Tankless Works
Long popular in Japan and Europe, demand water heaters are gaining popularity in the U.S. as old myths are being dispelled and “converts” are recommending them.
A tankless water heater heats water rapidly and on demand.
- When a hot water tap is turned on, water begins to flow and is detected by the water heater. A water pipe winds back and forth through the heat exchanger and water quickly reaches the desired temperature.
- Once hot water begins flowing, it will continue until the hot water tap is turned off. This is how unlimited hot water is supplied.
With a traditional tank style water heater, 40 to 50 gallons of water is kept hot until it is needed. When hot water is used, it is drawn from the storage tank. The heater also begins heating water, but it cannot heat water as quickly as it is being used. So, once the stored supply is used up, the water temperature drops dramatically.
Save Money and the Environment
Because tankless water heaters don’t heat water until flow is detected, no energy is wasted keeping water hot. Tank style heaters store hot water and periodically fire up to reheat water, day and night, and this constant reheating of water is wasteful and costs you money each month. A demand water heater can reduce utility bills while reducing the emission of carbon monoxide and other pollutants used to create the energy needed to heat the tank water heater.
There is another consideration: If you have unlimited hot water, will you start taking longer showers?
Many people are used to taking a shower of five minutes or so. After that the water starts to get lukewarm, then cold, and out you go. Will a tankless allow you to stay in the shower for an extra two or three minutes?
Ask yourself this: Do you really need to? An extra two minutes added to a five minute shower results in 40 percent more water usage and the energy used to heat the water. If you are not careful, you could wipe out any utility savings by lingering in the shower texting or playing a game on your smart phone (yes, people do this).
On the other hand, heating water day and night creates a lot of waste, so a little extra time in the shower thanks to a tankless water heater may not wipe out all of your savings. Exact numbers and savings depend on the number of people in your home, your hot water usage patterns, and the current efficiency or inefficiency of the tank water heater.
Work with a Staten Island plumber or water heater specialist to understand trade-offs, pros and cons.
Facts and Myths about Tankless Water Heaters
- Demand water heaters are sometimes called instantaneous water heaters. The name leads to a common misconception, that hot water comes out of the tap instantly. Not true. Just as with a tank water heater, hot water must travel through your home’s plumbing system before it reaches the tap. If it takes 60 seconds for hot water to reach your tap with a tank heater, it might take 70 seconds for a tankless heater. The extra few seconds is the time it takes a tankless unit to sense hot water demand, fire up the burner and bring the first bit of cold water up to the required temperature.
There are ways to get instant hot water, including the use a recirculation pumps, locating the water heater close to where the water will be used, or with an instant hot water spigot that is typically used next to a kitchen sink.
- Another myth is that tankless water heaters cannot really supply all the hot water that they claim. This myth stems from the fact that tankless water heaters require a lot more thought when making a selection. With tank style heaters, you simply pick the tank size that most closely matches expected demand (and making sure the space where the water heater is to be located can accommodate a larger size, if chosen). Tankless water heaters require that other factors be considered, including the starting cold water temperature and the gallons per minute (GPM) of simultaneous demand. When the proper sized unit is selected and correctly installed, it can deliver all the continuous hot water you require.
- Tankless water heaters are too expensive. While they are more expensive than tank style heaters, they also last two to three times longer than tank heaters. When you take their life span into consideration, they are actually competitive but cost more at the start. Add in reduced energy costs, the elimination of service expense to install one or two replacement tank heaters over 20 years, and the perks of having continuous hot water, tankless water heaters are definitely not more expensive over the long run.
- Tankless water heaters have a reputation that they can provide only lukewarm water to the tap at a sink. This reputation is not entirely accurate but it can be a weakness with tankless water heaters.
Consider how the unit works. As explained earlier, a tankless unit senses water flow and then fires up to heat the water. However, they require a minimum flow rate before they will begin heating. This is good because it means they don’t operate when a tap is dripping or someone leaves the tap on a little bit. But if you turn on the tap for just a gentle flow, it might not be enough to initiate heating. Add to this the extra few seconds it takes for the unit to fire up and produce hot water, brief use of hot water at the sink may be result in little or no hot water. The problem can be resolved by using hot water at full flow and/or by augmenting the hot water supply with a small, local water heater at the sink. Hot water circulating systems also can eliminate the problem.
Choosing the Right Tankless Water Heater
If you have decided to install tankless water heating in your home, you have options. The best thing you can do is involve a Staten Island plumber or water heater specialist who has experience with tankless installations.
A plumber who has nothing good to say about tankless water heaters is either inexperienced with tankless or unqualified, in either case avoid using them.
When determining the equipment you will use, a Staten Island plumber can help you decide whether to use just one water heater for your entire home, to plumb two units together in parallel, to install smaller units closer to the point-of-use, or even to create a hybrid system using small tank water heaters to speed hot water delivery and tankless water heater to sustain delivery. Obviously, such scenarios range from moderately more expensive over a storage-tank water heater to a very costly remodel project.
A Staten Island plumber can also advise you on whether a hot water recirculation system would be a good solution for your home.
Another consideration is whether to use natural gas or electric heaters. Solar pre-heating systems can even be integrated to further improve system efficiency.
How to replace a water heater.