Anyone buying a water heater should know that. A hot water heater is an important issue to consider for most remodelers, builders, and architects. Buyers have shifted their focus to energy efficient appliances that can save them money on their ever increasing power bill. Heating water is a huge part of the efficiency of any home as it can draw a lot of power, depending on what kind of water heater you have and your usage patterns.
The office of Energy Efficiency and Renewable Energy states that heating water is the third biggest expense in most homes. It can account for anywhere from 15%-30% of a home’s overall costs. An energy efficient water heater can effectively cut your power consumption, save homeowners big money in tough economic times.
Hot Water Heaters
With hot water heaters consuming a large chunk of your monthly power bill, it’s important to choose the best hot water heater for you. There are many different types of hot water heaters which can be broken up into a few major categories including gas heaters, electric heaters, and solar heaters as well as variations of each that include tank and tankless options.
The type of water heater that’s right for you will have a lot to do with the type of water heater you currently have installed, what type of climate you live in and how much hot water you plan to use every day. Gas can be the most efficient but is susceptible to power outages. Electric can be the most convenient and inexpensive to install, yet not as efficient as gas or solar. Solar can be a great alternative but only works in warmer areas that are exposed to lots of sunshine.
In this article, we will be taking a look at all of the different options facing a consumer looking for a new hot water heater. We will discuss the pros and cons of each type of water heater to help you make an informed decision.
Tankless Hot Water Heaters
A tankless hot water heater will heat your water on demand, only as you need it. A tankless heater can provide an endless stream of hot water and can even save you money in the process. Conventional water heaters have a large storage tank which must constantly be heated to maintain a proper temperature. In tankless heaters, the water is heated as it flows through the unit, so no water is ever stored.
When you open up a tap that dispenses hot water or use an appliance like a dishwasher or washing machine, your tankless water heater will detect the need for hot water and turn on immediately to begin heating the water as it flows through. The water coming into the heater is measured to determine how much power is needed to heat the water to the proper temperature, making a tankless heater an extremely efficient way to provide hot water to your entire house.
When you close the hot water tap or cease to draw from the hot water supply, a tankless heater will shut down automatically, using virtually no energy at all during down times. Conventional water heaters will continue to run, consuming power all day long, even if you aren’t at home or using any hot water. You will always have access to as much hot water as you need anytime you need it, day or night.
Tankless water heaters are offered in both gas and electric varieties, making them a valid option for homes with and without natural gas service installed. Electric versions make be 110 volts for single-use applications, such as installing under a single sink or shower to provide hot water for just one place. 220-volt versions are required to heat enough water fast enough to supply an entire household. Gas versions are also available for single use, though they are more typically used to provide hot water for an entire home. They will require larger gas lines than a traditional gas heater most of the time due to the amount of heat required to heat water as quickly as it is dispensed. This can drive up the cost of installation significantly.
A new tankless hot water heater has pros and cons just like any other hot water heater system. If you think you may be interested in installing a tankless heater, it’s important to know all of the positive and negative things that are associated with them. If your primary concern is to save energy, a tankless system is a great solution. Tankless water heaters are easiest to install when your home is being constructed or undergoing major renovations, as you will have to run necessary gas, power and water lines in and out of the unit.
Tankless Hot Water Heater Pros
- Energy Savings – The initial purchase of the water heater and installation may cost more than a traditional hot water heater, but the costs are justified with outstanding energy savings. A tankless heater only draws power when needed, so it will save you money when you aren’t around and not using any hot water.
- Continuous Stream of Hot Water – A tankless heater will provide you and your family and an endless supply of hot water. Even if the dishwasher and washing machine are both drawing hot water, your shower will still be steaming hot. Conventional tank systems require you to wait while more hot water is heated up, which can take a long time when all of the hot water has been used up.
- Smaller Size – Tankless heaters require much less space than a traditional tank water heater does. They are typically mounted on a wall and can be mounted inside or outside your home. They take up just a fraction of the space a 50-gallon water heater would and require no space at all on the floor.
- Less Water Damage – Water heaters with tanks eventually form leaks and can even rupture completely, leaving your home, office or apartment filled with 50 gallons of hot water, causing extensive water damage. The only risk tankless heaters face is a failure in the pipe fittings, which can be detected and repaired without large quantities of water being released.
- Life Expectancy – A quality tankless water heater could last you 25 years or more, while the average lifetime of a storage tank-style water heater is only about 12 to 15 years. This goes a long way in justifying the upfront costs associated with a tankless heater.
Tankless Hot Water Heater Cons
- Lag – Tankless heaters may be referred to as instant on, and although they may turn on instantly, the water definitely won’t be hot the moment you activate the faucet. This may be a disadvantage, though it is the same disadvantage that standard tank water heaters face as well.
- Inconsistent Temperatures – If you are turning your faucet off and on, you will experience inconsistent water temperatures as it can take 2-3 seconds for your tankless heater to turn on each time the demand for hot water stops and restarts. This won’t be a problem during continuous use, but should still be noted.
- Upfront costs – It can be expensive to convert your tank water system into a tankless hot water system. A tankless heater capable of heating water for your entire home may cost anywhere from $800 to $1200 or more, as opposed to a standard tank heater which costs significantly less, anywhere from $300 to $500. Installation is more expensive too. A tankless hot water heater will need beefy gas lines to provide on-demand hot water and will also require an electric circuit for fans and ventilation. This drives installation costs to well over $1000, while a traditional tank system will only cost about $300 to install.
Indirect Hot Water Heaters
If you have a home that’s heated using a hot water radiator, your best choice may actually be to use an indirect hot water heater. An indirect hot water heater uses the hot water generated by your radiator’s boiler to heat up your home’s water supply.
Indirect water heaters are an excellent choice for any home, even though they still require a storage tank to use. This type of water heater circulates a fluid through your boiler or heater that then passes through a heat exchanger built into the storage tank to heat the water. The heat storage in the water tank also provides enough radiant heat to keep your furnace or boiler from running as often. An indirect water heater combined with an efficient boiler or furnace, used with a highly insulated tank can actually be the least expensive way to heat your home and water.
Indirect Hot Water Heater Pros
- Lowest Life Cycle Cost – The cost of the United combined with the energy consumed during the life cycle of the unit is among the lowest of all water heaters. This makes indirect hot water heaters the smartest choice among energy-conscious consumers.
- Excellent Efficiency – This is especially true in colder environments or during colder months. The more your furnace or boiler run, the more efficient an indirect water heating system will be.
Indirect Hot Water Heater Cons
- Inefficient in Warm Climates – This is by far the greatest limitation of this style water heater. If you don’t run your furnace or don’t even have one at all, this type of water heater will not be a good fit for you.
- Not an Option for Everyone – You must have a furnace or boiler to use this type of water heater, which means that this won’t be an option for everyone.
Tankless Coil Water Heaters
A tankless coil water heater works by heating your water supply using a coil or heat exchanger that’s installed in your main furnace or boiler. When hot water is turned on, your water supply flows through the heat exchanger, providing on-demand hot water whenever needed. These water heaters rely on the heat from your furnace or boiler to heat your water directly, eliminating the need for a storage tank.
Because they require heat from a boiler or furnace, these types of water heaters are most efficient in colder regions or during colder months when your boiler and furnace are used more frequently. This makes them a relatively inefficient choice for warmer areas that don’t require any additional heating in the home or during hot summer months.
Tankless Coil Water Heater Pros
- On-Demand Hot Water – Your hot water is heated as needed, providing a continuous flow of hot water no matter how much demand is on the system.
- Energy Efficiency – These hot water heaters use the heat already being generated by your furnace or boiler, making them extremely efficient in cold environments. This can save you a lot of money on your monthly power bill, especially during colder months.
- Avoid Water Damage – Like all tankless systems, there’s no risk of a leak or rupture causing excessive water damage. The only place this type of heater can leak is from the pipe fittings themselves which can be quickly diagnosed without a big watery mess.
- Space Saving – The heat exchanger is the main piece of equipment in this system and can be incorporated into your furnace or boiler, which means this type of heater takes up virtually no additional space in your home.
Tankless Coil Water Heater Cons
- Inefficient in Warm Environments – This type of water heater is not recommended to anyone who lives in a warm environment and doesn’t need to heat their house more than a few months out of the year.
- More Expensive than a Traditional Water Heater – A tankless coil water heater will cost more to install than a traditional tank water heater. You will need to have a furnace or boiler that’s able to accommodate the heat exchanger used to heat the water.
Electric Hot Water Heaters
Electric water heaters can be found in a large percentage of homes and apartments. They provide the hot water you need for washing dishes, taking a shower as well as the hot water needed to run appliances such as your washing machine.
Electric water heaters store the heated water in a heavily insulated tank to keep it warm for delivery when needed. They will heat the water back up when it is not used and allowed to cool off. The tank is typically made from steel or glass and is heavily insulated to keep the heat in for as long as possible.
There is an electric heating coil, similar to what’s found in your oven that heats your water to the required temperature. A thermostat regulates how often the electric coil is turned on to heat the water, and will typically be set anywhere from 120 to 180 degrees or more, depending on how hot you like your water to be coming out of the faucet.
The tank itself is fed from the bottom, and hot water is taken from the top. This induces convection in the water as the heat from the bottom rises to the top, allowing the hottest water to be sent into your hot water lines first.
Electric hot water heaters come in a variety of shapes, sizes, and capacities. They are available with a storage tank, as described above, or as tankless heaters providing on-demand hot water as it’s needed. On a tankless system, the water passes through a heating element built into the heater which heats the water instantly.
The type of electric heater that’s best for you depends on a lot on your daily usage. The typical household will go through nearly 50 gallons of hot water per day. This amount of usage can actually make an electric tank heater more efficient than an electric tankless unit, although they may still cost more to operate than a comparable gas water heater. Most electric water heaters are rated by GPH (gallons per hour) which can give you an idea of how much hot water will be available at any given time.
Electric Hot Water Heater Pros
- Only Requires Electricity – Some older homes may not have access to natural gas which can be expensive to retrofit. All you need is a single electrical line to power your electric water heater.
- Easy to Install – Installing an electric hot water heater is relatively easy compared to other water heating methods. This can make installing a new water heater easy for the do-it-yourselfer or inexpensive when hiring a contractor to install. Installation costs are much lower than a gas water heater, especially if you don’t have gas lines currently available.
- No Pilot Light – Electric gas heaters don’t rely on a pilot light to ignite a flame to heat the water. This makes them more reliable than a gas water heater, as there is no pilot light that can be blown out by the wind. This isn’t typically much of an issue unless your water heater is in your garage or another high traffic area.
- Safer than Gas – Since gas water heaters rely on a pilot light to continuously burn, they may be a risk of igniting flammable gases such as those created by paint thinners, gas, and other chemicals. This is an especially important consideration for water heaters stored in the garage.
Electric Hot Water Heater Cons
- Susceptible to Power Outages – If your power goes out, you won’t have access to hot water until it comes back on. This might not seem like a big deal, but wait until that huge blizzard hit that knockout power and you’re left without hot water. No hot shower in the morning can make a cold day even less bearable. Live through just one power outage, and you may change your mind about your old gas water heater.
- More Expensive than Gas – Electric heaters are typically more expensive to run than gas water heaters. This makes sense as nobody would bother using gas water heaters if they were less cost effective.
- Slower Recovery Time – If you have exhausted hot water tank, an electric heater will usually take longer to heat your water back up. This leads to more downtime without hot water, especially when running the dishwasher or washing machine.
Electric Hot Water Heater Maintenance
It’s important to check the condition of your hot water heater tank regularly if your hot water heater is older than 6 years. The serial number will generally indicate the date of manufacturing, such as a serial number that begins with 197 (manufactured in 1997). You may also find codes like C98 meaning March of 1998 or 9912 meaning the 12th week of 1999.
It’s important to turn off the power to your electric water heater before attempting any maintenance or repair tasks. It’s recommended to flip the circuit breaker switch in your breaker box to disconnect power from your water heater completely. This can prevent any serious injuries caused by electrocution. If your breaker box isn’t marked, you may need to consult with a professional to identify the circuit your water heater is located on.
After power is turned off (and ONLY after power is turned off), you can turn off the inlet valve on your water heater. After you turn off the feed line, you can connect a hose to the drain valve, usually located on the front of your water heater near the bottom (Typically located near the thermostat and control panel). Open at least one hot water faucet in your home to prevent a vacuum effect in your lines. Also be sure the drain end of the hose is somewhere suitable for draining, and not just lying on your basement floor. Down a drain or out the window is suitable, assuming out the window is lower than your water heater.
Open the drain valve slowly and see if there are any leaks. If no leaks exist, you can open the valve the entire way to drain your hot water tank. If you do find a leak, take care of it before proceeding. Plumbers tape on the drain valve threads can go a long way in reducing or eliminating a leaky connection.
Once you have a good connection to the drain valve, turn the water inlet valve back on to flush out your tank and remove any debris that may have built up inside. This is the most important step and is overlooked by many homeowners servicing their water heaters. Keep draining until the water runs completely clear then close the drain valve to allow your water heater to fill back up.
Do a visual inspection on the rest of your tank to ensure that everything looks as though it’s in working order before turning your water heater back on. Be sure to vacuum out any dust or cobwebs that may have built up in your heater.
Always, and I always mean, make sure your tank is filled before turning the power back on. Electric heating elements can be ruined if they are turned back on with no water in the tank. If you are unsure if the tank is filled, leave the inlet valve open for a minimum of 30 minutes to ensure that the tank has been filled completely.
After the tank is filled and you can turn the power back on at the breaker box, follow the instructions in your water heater’s owner’s manual to complete the testing of the pressure release valve. Once you’ve checked your pressure release valve and verified that hot water had been restored maintenance is complete.
Gas Hot Water Heaters
Standard tank-style water heaters that heat water using natural gas are some of the most common water heaters installed in most homes. With just minor maintenance a gas water heater can provide you with years of trouble-free service. Gas hot water heaters can store 20, 40, even 50 gallons or more of hot water at any given time. Tankless varieties are also available though they are typically more expensive to buy and install than a traditional heater that utilizes a storage tank.
Gas water heaters function based on convection, a standard law of physics. Don’t be scared though, convection is simply a fancy way of describing the way heat rises. Cold water enters the bottom of the tank which is then heated by a gas burner below the tank. The hot water rises to the top, where it is distributed to your home.
The cold water enters the tank through what is referred to as a dip tube. Water enters and leaves the tank on the top, though the dip tube is much longer allowing it to reach to the bottom of the tank. Drawing water from the top of the tank ensures the warmest water in the tank is always being distributed while the coldest water in the tank is closest to the gas burner heating it up.
The steel shell you see on the outside of the tank is just a thin layer that covers the insulated water tank underneath. The water tank inside may be made from steel as well or may be made from glass. It’s recommended that you add insulated tank jacket around your hot water tank to increase efficiency. These can be found at any hardware store, and installation only takes a minute. Considering that heating water can be up to 30% of your household energy costs, an insulated jacket around your tank will quickly pay for itself.
Glass tanks have a long metal rod inside the tank itself that’s known as a sacrificial anode. This anode is used to draw corrosion away from the metal jacket of the tank to extend the life of the tank. Some glass lined tanks don’t have a separate anode, but instead, use the hot water outlet as an anode. Plastic lined tanks do not require the use of a sacrificial anode.
Gas water heaters require an additional vent be added to allow combustion gases to exhaust. The exhaust gases are hot, sent straight from the burner, which makes the ventilation flue a sort of heat exchanger that helps to heat the tank. Code enforcement requires that this ventilation flue is exhausted outdoors, which can add additional costs to installing a new gas heater to replace an electric heater.
Gas Hot Water Heater Pros
- Fast Recovery – Gas hot water heaters typically heat up much faster than electric heaters, up to 200% faster. For busy homes that demand large amounts of hot water, gas is a perfect choice.
- Less Expensive – Gas heaters can cost half as much to run as an electric water heater. This makes them a great choice for the budget conscious consumer looking to save money on their utility bills.
- Works During Power Outages – Going through just one power outage with an electric water heater can make you rethink your water heating strategy. Gas heaters will continue to provide hot water even with little or no power available.
Gas Hot Water Heater Cons
- More Dangerous – Let’s face it, there’s nothing safe about flammable gas, especially a gas leak. It’s important for homeowners to find a trained professional to install their gas hot water heater.
- Pilot Light Issues – Although fairly rare, gas water heaters are susceptible to the pilot light being blown out, rendering them inoperative. It only takes a minute to relight the pilot light, but who wants to deal with that if their water heater is in a cold basement in the middle of winter.
- Less Efficient than Tankless – Because most gas heaters use a tank to store the hot water, they will need to run off and on to keep the water up to temp. This can be an unnecessary cost for a home that’s not used very often, such as a rental or vacation home.
Gas Hot Water Heater Maintenance
Because you are dealing with flammable gases, gas water heater maintenance is more dangerous than electric hot water heater maintenance, which means you should take extra precautions, which are usually outlined in the owner’s manual for your water heater.
Before you begin any maintenance on your gas water heater, it’s recommended that you turn off the gas valve that leads to the heater. You can know that the valve is off for sure if your pilot light extinguishes itself after you turn the valve off.
The first thing to check is that there is proper airflow to the burner of your gas water heater. Most gas heaters are crammed into a closet somewhere or in a basement, which may be cluttered. It’s important to allow sufficient air flow to your water heater by keeping the area around it clear. It’s also extremely important to keep all flammable materials as far away from your water heater as possible. The pilot light is always burning which can easily ignite any gases that may build up around it.
It’s also important to make sure that the vent on the top of your water heater is free of dust, cobwebs, and debris to allow the air to flow out freely. This is important for providing your burner with enough oxygen to burn efficiently.
The next thing you will want to do is drain the tank by turning off the water inlet valve and attaching a hose to the outlet valve located on the front of the water heater near the bottom. Be sure to put the other end of the hose down a drain or out the window to avoid spilling water everywhere. Before you open the drain valve, be sure to open at least one hot water faucet in your hose to avoid a vacuum effect on the hot water lines.
Open the drain valve slowly to ensure the hose isn’t leaking anywhere. If leaks occur, you may try to tighten the hose or apply plumbers tape around the outlet threads before connecting the hose. Once you’ve got a good connection, open your drain valve all the way to drain your tank completely.
After your tank has drained, you can disconnect the hose, lifting it in the air all the way to the draining point to clear it completely. After that, you can open the water inlet valve and follow the instructions in your owner’s manual (or on the heater itself) to relight the pilot. It’s recommended to complete this maintenance routine every 2 weeks if possible.
Solar Hot Water Heaters
A solar hot water heater uses the power and heat of the sun to provide hot water to your home or business. Solar water heaters are especially effective in warmer climates and can be much more simple in design and cheap to produce. Solar water heaters are becomingly increasingly popular in the United States are have already been used for years in places like China, Japan, Europe and even India.
Solar water heaters can be broken up into two distinct categories, active and passive systems. Active systems will pump a fluid (other than the water you will be using in your home) through a solar energy collector. Passive systems use the natural power of convection to power the working fluid inside the water heater.
Most solar collectors are made from a simple insulated box with a glass top, and a piece of sheet metal below painted black that’s attached to copper pipes. In large commercial or industrial applications parabolic mirrors (shaped like a satellite dish) are used to concentrate sunlight to power a solar water heater. The heat generated by the sun is stored in a hot water tank, which is typically much larger than a standard tank found on a gas or electric water heater. The tank is extra big to make up for any bad weather or lack of ability to heat the water. The massive volume of the water keeps it warm for much longer. The working fluid that’s used to transfer the heat from the collector to the storage tank is typically some kind of anti-freeze that contains a corrosion inhibitor to prevent damage to the copper pipes carrying the fluid.
Solar Water Heater Pros
- Environmentally Friendly – Solar energy is a renewable resource that doesn’t produce any greenhouse gases like CO and CO2. This makes solar energy a clean resource that costs almost nothing once operational.
- Free Power – Once your solar water heater is set up properly, aside from occasional maintenance, you will have hot water for almost nothing at all. This can be a huge impact on your power bill which can be from 15%-30% water heating.
- Can be Used Year Round – Solar water heaters may work best in the summertime, though they can also collect energy from the sun on sunny winter days. Snow can even reflect sunlight onto your water heater or other solar energy devices during winter months.
- Financial Incentives – This is especially true for people living in the USA, Canada, and parts of Europe. The government wants people to go green, so they incentivize new technologies to help subsidize the purchasing of equipment. This can mean free power and money back in your pocket to cover the cost of installation.
Solar Water Heater Cons
- Initial Investment – Solar water heaters are far more expensive than any traditional water heater including gas, electric and various tankless systems. There may be government programs to help offset the costs of a new solar installation, so research is important before installing any system.
- Limited by the Sun – If the sun isn’t shining, you won’t be saving much energy. Most solar water heaters have built-in gas or electric heating elements that are activated when temperatures drop below a certain level. They help to heat your water on cloudy days.
- Outdoor Maintenance – Unlike traditional water heaters, solar water heaters are typically placed outdoors for maximum results. Like anything left outdoors, regular service and maintenance are required to keep things in tip-top shape.