Best tankless water heaters

If you have been using the same water heater for the last decade or so, it may be the time you got it replaced. In the recent years, there have come several choices and more energy efficient water heaters. The most efficient of all water heaters being the tankless water heaters. This guide presents you with some of the best tankless water heater options in the market.

 What are tankless water heaters?

You may have probably heard of the tankless water heater and their benefits. Tankless water heaters heat the water when it is needed and do not store the hot water thereby preventing energy loss in the form of heat. The heaters help save up to 30 percent of the water heating energy costs compared to the conventional water heating systems. Given that water heating accounts for about 20 percent of your energy bill, a thirty percent cut in the bill has a significant effect on your monthly bill. 

 Most of the tankless water systems have a flow of hot water at about 3.5 gallons to about 5.4 gallons of water per minute. This flow is enough for most home activities such as the shower and dishwashing.

 How to choose a tankless water heater

Just like other models, there are several options available in the market for the tankless water heaters. We have put together a list of the leading brands to help you make an informed choice. Given the popularity of the tankless water heaters, you may find some products that do not meet the standard quality requirements. Such heaters would be a waste of cash. Moreover, given the high prices, the stakes are high to pick the right tankless water heater for your home. Shall we get started? 

1.      How many appliances do you have at home that require hot water

The total water flow that is required if two or more of your appliances are working together should act as a guide to the size or the number of tankless water heaters that you will install at home. Every appliance has its minimum and maximum flow rates (gallons per minutes). Adding up these totals will give you the required gallons of hot water at any given minute. 

Let us consider a home that runs a hot water faucet at a flow rate of 0.8 gallons a minute and a shower whose head has a flow rate of 2.6 gallons a minute. If both were to run at the same time, you would need to have at least 3.4 gallons of hot water every minute. You can reduce the flow rates by replacing the fixtures with low flow heads. 

2.      Determine the temperature rise

The temperature rise is determined by subtracting the desired output temperature with the incoming water temperature. You can assume that the incoming water temperature will always be at 50°F. A lower temperature assumption helps you avoid undersized your unit. If you live in hot areas, the water temperature may be higher. Given most of the hot water functions require water that is heated between 100 to 115° F, in this example, you would need a tankless water heater that produces a temperature rise of 55°

You must check out for these two major characteristics when considering any model of the tankless water heater failure to which you may not get value for your money. The rest of the of the factors to consider such as the quality, warranty, durability, efficiency and others will be covered under specific products. Read on.

All types of tankless water heaters

There are several varieties of tankless water heaters in the market today. In terms of the technology used in production, we have three types of tankless water heaters

·         The non-condensing water heaters

 Non-condensing water heaters were the first generation water heaters in the market. They have an installed heat exchanger that helps heat the water on demand. Their heat efficiency factor (EF) is around 0.82 to 0.85. These types of heaters are common in Europe and South East Asia. They are durable a reliable.

However, one major drawback for the heaters is that a hot exhaust is included in the unit. This requires you to install a stainless steel venting that can be quite expensive. They also have lower energy efficiency, (they waste a lot of energy), especially where you need to use lots of water in short draws. (Such as washing your hands)

·         Condensing water heaters

These are the second generation tankless water heaters. In addition to the primary heat exchanger found in the first generation tankless water heaters, they have a secondary heat exchanger which reuses heat that was getting lost through the exhaust in the case above. This increases their efficiency of the units to about 92 to 95 percent.

This also makes the units to be cheaper to install as you can use the inexpensive PVC exhaust given that the air that gets out is cooler. However, just like the non-condensing water heaters, the heat efficiency goes down when there is short high water draws.

·         Condensing hybrid tankless water heaters

Condensing hybrid tankless water heaters are more common in the U.S. In addition to the features in the condensing water heaters; they have a small reservoir that is about a gallon or two. This reservoir becomes useful when there is a lot of hot water that needs to be drawn in a very short time. It ensures that the energy efficiency constantly remains at between 92 and 96 percent at any water draws. It effectively solves the drawbacks of both of the heater types discussed above.

 The water heater can also be vented using inexpensive PVC exhausts. Moreover, it can also deal with cold water sandwich issues that are found in the other types of water heaters. The cold water sandwich is the pressure fluctuations experienced between the incoming and hot water delivery pipes. The drawback in these models is the time lag that occurs between starting of the device and delivery of hot water where it is needed. You have to wait for the water to come to the faucet for a minute or two minutes. Being a new technology, a lot of improvements are expected in the near future. 

Types of water heaters by the source of energy

·         Electric water heaters

 There are varieties of electric tankless water heaters in the market today. Most of them have a metallic element that is heated by electricity to heat the water on contact.

 Pros

•    Electricity is clean and cheap in many countries around the world. The water heater offers convenience at cheap energy cost

•    Requires little maintenance

•     It is easy to install

 Cons

•    There are cheaper sources of energy such as natural gas and propane

•    Electric tankless water heaters are very expensive

•    Sometimes, you have to alter the power configurations at your home when installing an electric tankless water heater

•    The heating elements tend to be corroded with calcium deposits from the hard water over time. This means that you have to keep replacing the coil at least every year to increase its efficiency

With this knowledge in mind, lets us look at the leading electric tankless water heater brand in the market. Let’s go

SioGreen IR245 POU Quartz Elements Infrared Tankless water heater 

 Features

The siogreen Tankless water heater uses the top of class coilless technology that effectively gets rid of the metallic heating element in your heater. Instead, water is heated with infra-red technology that emanates from the quartz elements in the tank

It has a flow rate of up to 2 gallons per minute and a temperature rise of up to 60 °F. It can be used in short high water flow applications such as washing hands.

 It uses the 220v/ 4.5k and has an amperage of 18.75. It can be installed at homes without an extensive reconfiguration of the electric system

 It requires 1/2” NPS sizing water connection to enable it to provide the standard water flow to the required units 

It comes with a water adjustment valve, a wall mount bracket, and a rubber washer filter screen

 Pros

    The coilless technology prevents the calcium deposits on the heater. If you live in an area that has hard water, you may have experienced hard white deposits on the water heating elements. These deposits reduce the efficiency of your coil. The infrared technology solves the problem and enhances the durability of your water heater.

    It has a high flow capacity. Thus, it can be used at home or small business such as the salon or cleaning services providers

    Lack of metallic elements in the heater ensures that there is no corrosion of the internal parts of the heater. This further prevents the growth of algae and bacteria in the water.

    It also has a high-temperature rise delivering up to 1.2 GPM at 30 °F temperature rise and 0.6 GPM at 60°F. This means that it can be used effectively in short high water draws such as washing hands or hair at the salon

    It requires little or no maintenance at all. It is also easy to install

    The quartz technology ensures rapid water heating without any loss of heat. This saves you energy and money when it comes to paying the bills. 

    It is highly durable with an expected lifetime of 20 years

 Cons 

    It has water pressure problems between the inlet and the outlet, especially where you have to use an adaptor to reach the inlet and outlet pipe specifications.

    It may give you problems installing the brass ½” to ¾” male NTP adaptors to the output side. This is because the pipe sticking out of the water heater is very soft. This makes it conform to the tapered end of the adapter and binds to the 1/3 of a turn.

    It is not the best choice if you require water is over 105 °F hot

 Warranty

 The water heater has a warranty of eight years

Propane heater

 Propane heaters are common in areas where propane is used instead of the natural gas. The mode of functioning is similar to that gas tankless water heaters

 Why is it a great choice?

•    Propane is cheaper compared to electricity

•    Requires little modification of your gas system, except for a line to your heater

•    You may get credits from the local authority for switching over to green technology

 Cons

•    You will require an exhaust for your water heater, which is expensive

•    You may be required to upgrade your propane line to take care of the additional usage.

 Over to some of the leading propane tankless water heater brands

Eccotempt FVI-12-LP High Capacity Propane Tankless water heater

Features

•         This water heater has the capacity of delivering 11gallons of hot water. It has a flow rate of 3.6 GPM and a maximum pressure of 80PSI.

•         It also comes with a horizontal stainless steel vent kit which enables it to be used indoors without any safety concerns.

•         It offers 45 degrees F temperature rise at 3.6 gallons per minute. However, it can rise to 77 degrees F temperature rise at 2.3 gallons every minute. It minimum flow rate is 0.65 gallons per minute

•         For the safety of the occupants, it has a safe electronic ignition system that plugs into the standard 120V electric outlet

•         It has a digital thermostat and a water flow adjustment knob. You can also manually control the water temperature from the heater.

 Pros

•    It is easy to install and use at a home

•    It has inbuilt safety features to enhance safe use and avoid accidents

•    It has a high flow rate and can be used in a few applications concurrently

•    It has a high-temperature rise that saves you energy during the cold season

•    It can withstand short water draws without affecting its efficiency

•     It is an inexpensive and efficient propane water heater

Cons   

•         It may fail during the cold season especially in the basement due to weak heat exchanger tubing. Be sure that the vent is well insulated.

•         The user manual is not clear on how to set the  unit to achieve any required  water temperature

•         The company has a very short warranty for the replacement of parts. The parts replacement warranty only runs for thirty days after the purchase of the unit. You may also be forced to pay up for the cost of returning the unit for replacement

•         In some parts of the world, it is hard to get the 2.5” size of the vent pipe

•         You would need to have diaphragm pressure adjustments to accommodate lower water pressures of below 50 PSI

Rinnai V65EP 6.6 GPM Outdoor Lox Nox Tankless Propane Water Heater 

 Features

• •         This water heater is installed on the outside and delivers up to 6.6 gallons of water per minute.
• It has an energy an energy factor of 0.82 and can also be used with natural gas
• The water heater is certified for use in mobile homes
•  It requires up to 150,000 BTU
• It has an in-built temperature lock that prevents unauthorized or accidental changes in water temperature.
• An error indicator alerts you when there is a problem with the system
• It comes preset at 120 °F by the manufacturer but can be adjusted upwards to 140 °F by the installer
•  It can work with all types of Rinnai Digital Controllers with the range of between 98 °F and 140 °F
• The unit is compatible with South Coast Air Quality Management District regulations on NOx emission levels (14 ng/J)
• It comes with a ten-year warranty on the heat exchange unit and a year warranty on labor

Pros

•         The unit is very durable and requires very little maintenance. It is built on Rinnai’s tested technologies to deliver high-quality service for a long time. 

•         It has robust safety controls to prevent accidental damage to the unit and lower the risk of fire at home

•         It has a high efficiency at 0.82 delivering hot water at great energy savings. 

•         It is easy to install on the outside and requires little maintenance. However, you should have a professional installer do it for you.

•         You can control the performance of the unit using a full range of Rinnai controllers

•         It accepts both propane and natural gas. If you have to move from area to another, you will not have to replace the unit.

•         It is ultra-compact and reliable 

•         It has high-temperature rise and delivers hot water in a matter of seconds

•         It is preset for ease usage unless you need hotter water

•         Its efficiency does not go down with short water draws

 Cons

•         There are a few controls on the unit. If you would like to manage your unit much better, you need to buy Rinnai controllers from the stores which is an added cost

•         This is a non-condensing type of tankless water heater. Despite its high efficiency, there is a lot of heat that still gets lost through the exhaust.

Marey Power Gas 10l Digital Panel Tankless water heater

Marey Power is a propane tankless water heater that does not use electricity to ignite the system to deliver hot water. It uses the electrical pulse ignition that uses 2-D cell batteries to ignite the water heater. There are natural gas and propane models of the tankless water heater. You can also use it from a gas cylinder but you need to but a gas regulator and a hose for connection.

 Features 

•         It has a faucet activated water flow. Thus, when you turn on your faucet, the unit delivers hot water in an instance

•         You can control the water flow and the gas usage in the unit by use of the knobs on its face

•         It has a digital panel that among other things show you the temperature of the incoming water. This way, you can adjust the gas to achieve water temperature you need within a short time

•         It also has an inbuilt Anti-combustion and gas pressure regulator. This is meant to ensure that the gas does not burst into flames if it came to the unit to high pressure. The enhanced safety makes it possible to use indoors.

•         It can work with both low and high-pressure water flow between 3.6 and 145.0 PSI

•         Its output is 3.1 gallons per minute

 Pros

•         Since it uses a replaceable battery, it can be used even when there is no electricity supply. Moreover, its installation at home does not increase your electricity bills.

•         It has several easy to use controls that make it easy for you to set the temperature that you need for your water without technical assistance.

•         You can reign on you gas usage by controlling the amount of gas that is burnt per minute. If you require less water, you do not need to burn lots of gas to heat the water. This feature helps you save on the gas bills.

•         The faucet activated water flow adds convenience in that you do not need to start the unit manually every time that you need to use hot water. It works automatically.

•         It has high-level safety controls to ensure safety when using gas at home. Its safety features prevent accidental ignition of the gas, leakage, and combustion at high pressure. 

•         Its ability to take low and high water pressure makes it useful for different applications both at home and in business premises

•         It has low installation costs as it uses the ½” gas line along with Flue duct type for the exhaust system. You will not look had for these items in your local hardware shops.

Cons

•         It has low energy efficiency at between 54 percent and 80 percent. A lot of heat is lost through the exhaust as the heater works

•         The faucet activated water flow can lead to hot water loses and use up the electricity when  accidentally left on if there was no water supply 

•         Despite the rating that it can work with low-pressure water flows such as those used in water home heating systems, it may not work well with water pressure of below 10 PSI.

Natural gas Tankless water heaters

The natural gas tankless water heaters work in the same way as their propane counterparts and are used in parts where natural gas is supplied instead of the propane gas. The benefits and shortcomings of using natural gas are similar to those of propane gas discussed above.

 Let us go through some of the leading natural gas heater models

Rheem RTG-64XLN 6.4 GPM Low NOx Outdoor Tankless Natural Gas Water Heater 

 This natural gas tankless water heater is designed for use outdoors. It has a compact design for use both at home and commercially. The manufacturer offers a warranty of 12 years for the heat exchanger and five years for labor and parts.

 Main features

•         A low NOx version heater complies with most emission control regulations across different states. It meets the SCAQMD requirements for rule 1146 on the environment protection.

•         Its water flow stands at 6.4 gallons a minute. It delivers the hot water at the rate of 35 degrees F temperature rise.

•         It is a medium efficiency tankless water heater with a heat efficiency of between 74 percent and 84 percent

•         It uses the standard 120V AC. The power connection can be hardwired into the unit for enhanced safety, or a plug is used instead. It is recommended that you use the hardwired option as it is safer and is the option that comes with most outdoor heating units.

•         It uses an all copper heat exchanger. This increases it heat efficiency and deals with possible corrosion of the system. For increased durability, it used an overheat film wrap that protects the heat exchanger from damage when in contact with the cold water.

•         It has minimum gallons per minute rate of 0.26 and a minimum GPM activation flow rate of 0.40

•         The package includes a digital remote control, a manual gas isolation valve for increased safety and a 10ft thermostat wire.

 Pros

•         It is highly durable and has low maintenance due to the use of all copper heat exchanger and the protective measures

•         It can work with extremely low water pressures

•         The remote control offers convenience when you need to adjust several settings on the system given that it is installed high on the wall

•         It works well even in high altitudes of up to 9840 feet above sea level

•         It heats up very quickly and delivers up to 160 degrees F in less than a minute  

•         The long warranty period points to a durable product

 Cons

•         Requires a professional assistance installation

•         Its users’ manual is a little complicated. Some users may find it hard trying to set the correct water flow for the unit. 

•         It is quite expensive both as a unit and the labor during installation

 Eccotemp FV1-12-NG High Capacity Gas Tankless Water Heater

Eccotemp FV1-12-NG High water heater is fired by natural gas and is made for use indoors. It can be used both at home and commercially where moderate amounts of water are required. It can also be used in cottages, vacation cabins, and manufactured homes.

Features

•         The unit has a maximum flow rate of 4 gallons per minute. It offers a temperature rise of 45 degrees F at this flow rate and 77 degrees F temperature rise at the water flow rate of 2.3 GPM.

•         It is plugged into standard 110-120V outlets where it consumes two watts of power when idle and 10 watts of power when in operation

•         The unit has a digital display on its face as well as an internal exhaust fan

•         The package comes with horizontal stainless steel vent kit that is easy to install.

•         It has separate gas flow and water controls. You can use the controls to make precise gas usage settings as well as the water temperature that you need

•         It utilizes a power ventilation electronic ignition system to enhance its performance

•         The power ignition is water pressure activated (a minimum of 40 PSI)

•         It requires a gas rate of 25,000 to 44,500 BTUs. It has been tested to work at this rate up to 5500 feet above sea level

•         A medium efficiency unit serves at an energy factor of 79 percent

 Pros

•         It has a high hot water delivery capacity that enables more than one hot water applications at the same time. It can also deliver short water draws without a high fluctuation in efficiency

•         It uses true ½” NPT water fittings, standard used across different areas. You will not have sweat out there looking for water fittings

•         It has easy to use control knobs that make it easier for you to set the exact water temperature you want to use as well as the amount of gas you would like burned. You can read the settings with ease on the display panel.

•         The inbuilt safety features make it safe for use indoors even to the small houses

•         It is cheaper than most of the brands that deliver similar quality of service

•         It is easy to install and vent through the wall. However, it is advisable that you have it installed by a licensed plumber to ensure safety

Cons

•         The unit may heat up and shut down when working with low water flow. You can reduce such instances by adjusting the gas knob to low gas usage when using low flow faucets.

•         It may not serve you well if you have more than one application that requires a lot of water. Despite its 4 GPM rating, it will deliver less water when you use ¾” outlets. Consider using ½” outlets instead. (They have a lower flow)

•         It does not modulate the flame to match the flow. This means that it does not adjust automatically to the flow of the water. Thus, in high flow situations, the water may get cold, and in low flow, the water may get too cold. You have to maintain constant water flow to ensure that the water temperature stays constant all through. 

•         The manufacturer only offers a two-year warranty on the unit and one-year warranty on the parts.

Takagi-T-KJr2-OS-NG-Outdoor-Tankless-Natural/dp/B0057X23NW/

Takagi-T-KJr2-OS-NG natural gas tankless water heater is designed for use on the outside. It can also be converted into a direct-vent unit for use in heating the house. It is ideal for small homes and radiant heating applications at home 

 Features

·         It requires the natural gas at a rate of 19,500 to 140,000 BTU an hour. It can work well even in high altitudes.

·         It comes with an internal freeze mechanism to prevent damage during the very cold weather.

·         It has an energy efficiency factor of 82 percent

·         It can reach a maximum flow rate of 6.6 gallons per minute. It delivers 2.1 GPM at 122 degrees F temperature and 1.6 GPM at 140 degrees F. The flow rate increase with the increase in inlet pipe temperature.

·         It has a temperature rise of up to 70 degrees F  

 Warranty

 It comes with a 12-year heat exchanger warranty, 5-year warranty on parts and a year’s warranty on labor

Pros

·         It is an inexpensive solution for delivering hot water at home as well as heating small homes.

·         It comes with an energy star rating for energy efficiency. Thus, it will not bring you energy costs up when installed.

·         It is a durable unit that lasts for up to ten years

·         It meets the NOX emission standards set by several states across the world

·         It is easy to maintain and operate at home. You can also set a default water temperature if you do not want to keep adjusting the settings 

·         It is easy to install. However, it is recommended that you hire a licensed personnel to install the water heater.

 Cons

·         The unit cannot be used for moderate to heavy hot water applications

·         It is not recommended for use in an application that regularly requires high water draws.

·         With constant use, the water heater makes a loud humming noise. Although it does not get damaged with the use, it may feel uncomfortable

·         You have to regularly maintain the unit if you have to use it regularly