Today, the majority of residential and commercial properties produce the bulk of their hot water using one of the many types of water heating systems. Gas systems, in particular, remain popular due to their reliability and the relatively low price of gas when compared to other fuel sources such as electricity.
When on the hunt for a new system for your property, you should opt for models that will meet your hot water demands, but also do it efficiently and help save you money in the long run.
In order to achieve this goal, you need to take into account the different types of water heaters on the market and figure out which size and fuel type are best for your particular circumstances.
- Types of Gas Water Heaters
- Traditional Storage Heaters
- Storage Heaters:
- On-Demand Water Heaters
- Tank vs. tankless heaters
- What Size Water Heater do you need?
- Sizing for a Tankless Heater:
- Sizing for a Storage Heater:
- Our Top Picks
- Rheem Direct Vent Tankless Natural Gas Water Heater
- Takagi Indoor Tankless Gas Water Heater
- Eccotemp i12-NG Indoor Tankless heater
- Rheem Classic Residential Gas Water Heater
- A.O. Smith ProMax Plus Gas Water Heater
- Final Words
Types of Gas Water Heaters
You may not have given it much thought before, but not all water heaters are made the same. Understanding the pros and cons of each can help you determine which is most suitable for your unique situation.
Traditional Storage Heaters
These are by far the most popular type of heater used in the home and provide a constant pool of hot water to make use of on demand. Hot water is released whenever you turn the tap after which cold water is added to the tank to ensure the reservoir is maintained.
As the temperature of the water is heated throughout the day, fuel use can be substantial as it’s essentially being used when you don’t actually need hot water. This is referred to as standby heat loss, which can be avoided by utilizing a tankless water heater. One of the major reasons storage heaters remain popular is due to the upfront costs being considerably lower than other types of heaters, however, in the long term, the actual running costs may be substantially higher.
- Cheaper up front costs
- Large supply of hot water on demand that’s likely to meet all of your uses
- Straightforward installation
- Substantially more expensive to run
- Much less energy efficient
- Major risk of damage if ever a leak occurs
- Once empty you need to wait until water is refilled and heated
On-Demand Water Heaters
Also called tankless heaters, these are a modern approach to heating water that can be much more efficient and help to save you a substantial amount of money in the long run.
On-demand heaters work by only heating water when it’s needed, for example when you are running the shower or using a hot tap. When the hot tap is turned, water travels to the heater and in the case of gas heaters; a gas flame heats the water. This means you have the advantage of hot water on demand without the inefficiency and cost of having to keep the water heated constantly.
Tankless/On Demand Heaters:
- More energy efficient
- Helps to save space
- No standby heat loss
- Substantial upfront costs
- Limited capacity in terms of flow rate
- May need major renovation work to install
Tank vs. tankless heaters
Ultimately tankless heaters are cheaper to run than their storage heater counterparts since you only heat the water when you are using it. However, they have their own limitations; for instance, they have a limited water flow – typically around 3-5 gallons per minute. This can pose a potential issue in homes where there is simultaneous demand for hot water, for instance, if you wanted to run a bath and do the washing up, you may find yourself running low on hot water. Storage heaters, on the other hand, already have a large volume of hot water, so it’s likely that you will have an adequate amount to fulfill all reasonable demands at the same time.
What Size Water Heater do you need?
Once you have determined which type of gas heater you want to install, it’s important to figure out what size heater you’ll need for your home. By installing the right sized heater you can ensure you are being as efficient as possible and therefore helping to be cost-effective.
Sizing for a Tankless Heater:
The main thing to remember when looking for a tankless or on-demand heater is that the size you choose will determine the flow rate. They are typically given different ratings dependent on the greatest temperature increase possible at a certain flow rate. As a result, you need to think about how you are likely to use your hot water on a regular basis.
Are you likely to be using different hot water sources at the same time regularly? Or more often than not are you going to be using a single hot water outlet?
To work out what size gas tankless water heater you require, follow these steps:
- How much hot water do you require within a certain period of time?
To figure this out, you need to determine how much water each facility in your home utilizes in gallons per minute (GPM). Think about how many hot water outlets you are likely to use at any one time and then total these up. These are some common values for typical household hot water outlets:
- Dishwasher: Between 1.0 – 3 GPM
- Shower: 1.0 – 2 GPM
- Kitchen faucet: 3.0 – 6 GPM
- Work out your properties required temperature increase
Figure out how hot you need the water to become, this is typically around 120 degrees Fahrenheit. Therefore, if you live in a location with a normal water temperature of 50, you need to subtract 50 from 120. This gives you 70 degrees Fahrenheit, therefore your required temperature increase.
Sizing for a Storage Heater:
In order to size a storage heater, you should use what is known as the first-hour rating. This is the amount of hot water the heater can generate each hour. This varies as a result of the tanks capacity, fuel type and size of the burner.
The first-hour rating is utilized on all new storage heaters and should be found on the packaging and accompanying literature. Determine the rating you require by using your 1-hour maximum hot water demand. An easy way to do this is by thinking about what time of the day you require the hottest water and don’t forget to consider the number of people too.
For an estimate use the following formula:
Average gallons of hot water used x times used within an hour = gallons used per hour (this is your maximum hot water demand)
Now that you know a little more about the types of water tank heaters, we have analyzed and compared some of the most popular units in the tankless water heater reviews below.
Our Top Picks
The Best Tankless Gas Water Heaters:
Rheem Direct Vent Tankless Natural Gas Water Heater
Gallons per minute (GPM): 9.5
Ventilation: Direct-vent system
Founded in California all the way back in 1925, Rheem has a solid track record in water heating innovation and this unit is by far one of the best tankless water heaters out there with a worthy reputation.
One of the greatest benefits of on-demand water heaters is how easy they are to use, with digital control and a clear and informative display screen, this heater couldn’t be any simpler to use. The display panel provides all of the usual information including water temperature settings and error messages should something go wrong. There’s a standard temperature, but you can change it with the arrow keys, although once you’ve determined the temperature on installation, there’s no reason to alter this again.
All heaters create some level of noise when running, and the Rheem creates a very silent hum when the fan is in action, which can be heard whenever you run the hot water. However, once it’s up and running and pumping out the hot stuff, it doesn’t make a significant sound. The unit has a hot water flow rate of 9.5 GPM making it a good option for the average household.
To install this heater will take between 3-6 hours and it is a relatively straight-forward process. This involves hooking up the water lines and then the gas line, which entails fitting a sediment-trap and tee. Other than that, you will probably need to fit some new gas pipework and mount it in an appropriate home location – although keep in mind that it will need to be somewhere where the ventilation can easily be installed.
Takagi Indoor Tankless Gas Water Heater
Gallons per minute (GPM): 10
Ventilation: Direct-vent system
This is one of the smallest units in the natural gas range by Takagi and so is best suited for small properties and those with limited space. As a result, if you’re struggling for space but want to install a new heater, this is a good choice. The price point is also extremely budget-friendly, although don’t forget to budget for the installation, as this is often overlooked.
Its modest size has a substantial flow rate of 6.6 gallons of water per minute (GPM) at an impressive 350F, which is more than enough for a modest sized house, with multiple tenants, even during cold periods. This GPM is more than adequate to provide enough hot water for two bathrooms being used simultaneously, so you don’t have to worry about any queues forming in the morning – although it’s always advisable to use a low-flow showerhead if you plan on doing this.
Installation wise it is simple and straightforward, you will need to install adequate ventilation to the outside of your home which can be done via a vertical vent or less traditional horizontal venting. Ensure you always have heaters installed by a professional to avoid any potential safety concerns and although it may seem like a lot it’s definitely a worthy investment – and remember, it’s probably going to last you a number of years.
Eccotemp i12-NG Indoor Tankless heater
Gallons per minute (GPM): 4.8
Ventilation: Direct-vent system
This compact tankless heater is ideal for smaller homes, cabins, and outbuildings where using a fair amount of hot water is required. The black glass design makes it look somewhat appealing for a heater – this is ideal for small living spaces with limited spaces as often there’s no other choice but to have it on display.
The contemporary aesthetic is also matched well with the latest innovative features including touch screen capability and an LCD display that displays the set temperature and the GPM rate. It’s also equipped with a child lock, so you can be extra sure that your little ones won’t be getting themselves into any trouble.
It provides a total of 80, 000 BTUs which is enough to get the water up to temperatures reaching approximately 350F temperature increase when running at 4 GPM. The installation process is less complicated than the larger models and comes with a horizontal stainless steel vent kit which is a nice bonus and saves you on making another purchase later on down the line.
Perhaps the best part about this model is how efficient it is – yes it’s small but you’ll be hard-pressed to find one that only uses 2 Watts when not in use and 1.07 when running.
The Best Gas Storage Heaters:
Rheem Classic Residential Gas Water Heater
Storage Capacity: Up to 71 gallons
BTU’s: Up to 42,000
Ventilation: Power vent system
As mentioned previously storage heaters can provide a large reservoir of hot water to meet the demand of large and demanding households. This heater by Rheem is a perfect example of that and with a storage capacity of 50 gallons; it provides enough hot water for large homes with large families.
The startup mechanism comes in the form of a push button ignition that ensures safety to users and a fast and efficient warm-up. It’ll take a few hours to heat up, but once it does will hold 50 gallons and is capable of producing around 90 gallons within an hour. This is ideal for homes where many people may want to use the hot water simultaneously.
The valve is extremely useful and features a self-diagnostic feature to provide peace of mind and keep tabs on performance and highlight any issues which may occur. All of the required water connection pipework and valves are included, which means you can get on with installation from day one.
A.O. Smith ProMax Plus Gas Water Heater
Storage Capacity: Up to 71 gallons
BTU’s: Up to 40,000
Ventilation: Power vent system
Founded in 1836 A.O. Smith is a highly esteemed heating manufacturer, which is always an advantage when buying an appliance that demands optimum safety and efficiency.
A major advantage of the ProMax is the Blue Diamond glass coating that helps to protect against corrosion, a common reason why so many storage heaters have such a short shelf life. The Dynaclean diffuser dip tube also helps tackle another common issue with storage heaters – lime and sediment deposits. These features combined help to prolong the life of the storage heater providing peace of mind and making your money go further.
The estimated cost of running this large storage unit is reasonable for the year and definitely cheaper than other types of water heating such as wood powered furnaces and boilers.
With a 30 gallon tank and other sized options up to 50 gallons, this gas water heater is ideal for small, medium and large homes. The gas valve itself is also self-powered, meaning you don’t have to rely on any external power source – helping to save a little bit more on energy consumption and perhaps even more suitable for the prepper.
There is no such thing as the best tankless gas water heater; the right unit largely depends on your individual circumstances. If you have a large family and large home with a lot of demand for hot water from everyone, a storage heater is probably advisable, even though it has associated inefficiencies and is more expensive to run.
On the other hand, if your demands for hot water are about average and the size of your home is average too, then the best gas water heater for you is a tankless water heater, such as the Rheem gas water heater. There is no doubt tankless water heaters are more efficient and cost-effective and anything that helps you keep more of your hard-earned cash can’t be a bad thing.