A reliable 100 gallon water heater is one of those things you don’t think about until you need it — especially when cold weather hits. Heating water on the stove or with portable heaters just doesn’t cut it for a busy household.
Water heaters are available in two different models: storage types and instant (tankless) types. When compared to instant options, storage water heaters provide a continuous supply of hot water without pause.
However, 100 gallon water heaters are a bit pricier and take additional wall-mounting space.
While purchasing a hot water tank, you should consider the vital points covered in our reviews below.
This insulation jacket fits all 20 to 100 gallon tanks and reduces heating cost bills by 9%. It cuts heat loss by up to 40% and improves water heating efficiency up to 95%, all while being lightweight and easy to install.
Quick Comparison Chart
| # | Water Heater | Our Rating | ||
|---|---|---|---|---|
| 1 |  |
Hot Water Heater Jacket | ★★★★★ | Check Price |
| 2 |  |
Rheem Commercial | ★★★★★ | Check Price |
| 3 |  |
EcoSmart ECO 11 | ★★★★☆ | Check Price |
| 4 |  |
EcoSmart ECO 27 | ★★★★☆ | Check Price |
| 5 |  |
Bosch Mini-Tank | ★★★★☆ | Check Price |
| 6 |  |
Chronomite SR-20L | ★★★★☆ | Check Price |
| 7 | |
Chronomite SR-15L | ★★★★☆ | Check Price |
| 8 |  |
Rheem RTEX-18 | ★★★★ | Check Price |
| 9 |  |
Stiebel Eltron | ★★★★ | Check Price |
| 10 |  |
Rinnai V Series | ★★★★ | Check Price |
1. Hot Water Heater Jacket — Best Overall
Hot Water Heater Jacket Energy
This insulation jacket fits all 20 to 100 gallon tanks and reduces heating cost bills by 9%. It cuts heat loss by up to 40% and improves water heating efficiency up to 95%.
Pros
- Reduces 9% heating cost bills
- Reduces heat loss up to 40%
- Improves efficiency of water up to 95%
- Reflects 97% of radiant heat back to source
- Lightweight and easy to install
- Passed California indoor air quality standard
Cons
- Doesn't heat water on its own
- Requires existing water heater to function
- May not fit all non-standard tank shapes
This insulation jacket best suits large families and fits up to 100 gallon tanks. It reduces 9% heating cost bills while cutting heat loss up to 40%.
It’s fire rated Class 1 / Class A and is non-toxic. The irritant-free material won’t irritate skin, eyes, or throat when using water heated with this jacket.
It improves the efficiency of water heating up to 95% from that of all water heaters in use today. This kit provides an additional R-5 to your tank system which also has an E-value of 0.03.
That means it reflects 97% of radiant heat back to its source.
This water heater jacket is lightweight and easy to install. It comes with SSR kits that are mold and mildew resistant and non-toxic.
It has passed the California standard (IAQ CA01350) for indoor air quality.
It’s very handy and easy to clean. It fits gas or electric water heaters and contains no fiberglass.
It accommodates all 20 to 100 gallon tanks with ease.
2. Rheem Commercial — Best Commercial
Rheem Commercial Hot Water
This commercial storage tank features proprietary steel formulation with two coats of high-temperature porcelain enamel for maximum corrosion resistance and two heavy-duty magnesium anode rods for longer tank life.
Pros
- Suitable for commercial purposes
- Proprietary steel formulation with porcelain enamel
- Two heavy-duty magnesium anode rods
- Can pass through a 30-inch opening
- 80% draw practicality in parallel manifold
Cons
- T and P valve must be ordered separately
- Higher price point for commercial grade
- Requires professional installation
This 100 gallon water heater is best suitable for commercial purposes. It comes with a proprietary steel formulation having two coats of high-temperature porcelain enamel which maximizes corrosion resistance.
This heater comes with two heavy-duty magnesium anode rods that are installed for longer tank life. The model ST120 can also pass through a 30-inch opening.
The circulating line connections and hot outlet use 2-inch NPT fittings. It comes with openings for relief valve and temperature control as well.
The T and P valve must be ordered separately based on the water heater.
Rheem-Ruud industrial storage tanks are vertical tanks designed for applications that need large volumes of hot water in brief intervals. When used with Rheem-Ruud water heating equipment, these storage tanks offer the strength needed for numerous industrial applications.
Installed individually or in a parallel manifold, these storage tanks can provide 80% draw practicality without a considerable temperature drop in divorced temperature packages.
3. EcoSmart ECO 11 — Best Tankless
EcoSmart ECO 11 Electric Tankless Water Heater
EcoSmart's self-modulating technology adjusts electricity output for ideal water heating. The ECO 11 saves up to 50% in water heating costs with its compact wall-mounted design.
Pros
- Saves up to 50% in water heating costs
- Compact wall-mounted design frees up floor space
- Digital temperature management for precision
- Self-modulating technology adjusts energy usage
- Easily exchangeable parts for maintenance
Cons
- Limited to smaller applications in cold climates
- Requires adequate electrical supply
- Not suitable for whole-house in colder regions
EcoSmart electrical tankless water heaters are leading the industry with their proprietary self-modulating technology. This technology allows the device to manage its electricity output for top water heating performance.
The ECO 11 is well-suited for small rental properties or any smaller point-of-use application. It’s designed to heat water efficiently and performs best in climates of 67 degrees Fahrenheit and higher.
It can be used for a few applications depending on your climate. In warmer climates, the ECO 11 can manage sinks running at the same time and one shower.
In colder climates, it can handle 2 sinks simultaneously.
When sized properly, your tankless unit can offer endless on-demand hot water. It heats water as it passes through the unit rather than storing it in a tank.
EcoSmart tankless water heaters only activate when hot water is needed, saving you up to 50% in water heating costs.
Traditional tank heaters take up plenty of space. EcoSmart’s sleek wall-mounted design frees up floor space for storage.
It features the most advanced self-modulating technology, using only the amount of energy that’s required at any given moment.
4. EcoSmart ECO 27 — Best High Capacity
EcoSmart ECO 27 Electric Tankless Water Heater
The ECO 27 handles higher demand with the same self-modulating technology as the ECO 11. It delivers endless hot water for multiple applications while saving energy and floor space.
Pros
- Handles multiple applications simultaneously
- Self-modulating technology saves energy
- Compact wall-mounted design saves space
- Digital temperature management included
- Saves up to 50% in water heating costs
Cons
- Higher electrical requirements
- Professional installation recommended
- Higher upfront cost than tank models
The EcoSmart ECO 27 brings the same self-modulating technology found in the ECO 11 but with a higher capacity for larger households. It manages its electricity output to make sure best water heating at all times.
The ECO 27 is designed to heat large volumes of water efficiently and is best suited for climates of 67 degrees Fahrenheit and above. In warmer climates, it can handle sinks and a shower running simultaneously.
When properly sized, this tankless unit provides endless hot water on demand. It heats water as it passes through the unit rather than storing it.
This approach eliminates heat loss that occurs with traditional tank storage.
EcoSmart tankless water heaters only activate when you need hot water. This significantly reduces energy consumption and can save up to 50% in water heating costs compared to traditional tank systems.
The compact wall-mounted design frees up floor space, making it ideal for homes where storage is limited. All parts are easily exchangeable, and the digital temperature management system provides precise control over water temperature.
5. Bosch Mini-Tank — Best Point-of-Use
Bosch Electric Mini-Tank Water Heater
This Bosch mini-tank features 98% thermal efficiency and plugs into a standard 120-volt outlet. It mounts under your sink for instant hot water at the point of use.
Pros
- 98% thermal efficiency rating
- Plugs into standard 120-volt outlet
- Can be shelf, wall, or floor mounted
- Eliminates long waits for hot water
- Supplies up to two sinks at a time
Cons
- Limited capacity for point-of-use only
- Not suitable for whole-house heating
- Requires cold water line connection
This Bosch point-of-use mini-tank fits beneath your sink to provide hot water right where you need it. For smaller capacity needs, you may also want to explore our best 50 gallon electric water heaters. It comes with 98% thermal efficiency and a premium glass-lined interior for an extended service life.
The 36 to 37 inch cord plugs right into a 120-volt outlet for independent setup. You can also connect it in-line with a larger hot water supply.
This heater features a fast recovery rate.
It eliminates long waits for hot water at your sink by providing on-demand hot water. It can supply up to two sinks simultaneously.
The unit can be shelf, wall, or floor mounted with the included bracket.
Simply tap into the cold water line and install the heater directly at the sink. These units fit neatly below a sink, even in a small cabinet space.
They have a sleek design that blends in easily with existing decor when installed in a visible location.
6. Chronomite SR-20L — Best Instant Heat
Chronomite SR-20L/120 HTR SR
Chronomite uses silicon chip technology to deliver pre-set water temperatures in 2 seconds without risk of scalding. It operates only when hot water is requested, reducing energy waste.
Pros
- Delivers hot water in 2 seconds
- 98% thermal efficiency
- No risk of scalding with pre-set temperatures
- Compact design fits under most sinks
- Only operates when hot water is requested
Cons
- Limited to point-of-use applications
- Lower flow rate than whole-house systems
- Requires dedicated electrical circuit
Chronomite was the first to implement silicon chip technology in water heaters. It allows for a pre-set or regulated temperature that delivers consistent heating in 2 seconds, as opposed to the 6 seconds offered by competing tankless water heaters.
Chronomite is installed for point-of-use and is only operational when hot water is requested. This dramatically reduces delivery time and inefficient use of electricity.
The heater comes with 98% thermal efficiency. It features premium glass-lined fabric for an extended service life at 12 amps and 120 volts.
It can be shelf, wall, or floor mounted with the included bracket.
Simply connect it to the cold water line and install the heater directly at the sink. These units fit neatly below a sink, even in a small cabinet space.
Their sleek design blends in without any hassle with existing decor.
7. Chronomite SR-15L — Best Energy Saver
Chronomite SR-15L/120 HTR 120-Volt 15-Amp
This 120-volt 15-amp Chronomite model uses silicon chip technology with 98% thermal efficiency. It dramatically reduces hot water delivery time and inefficient electricity use.
Pros
- 98% thermal efficiency saves energy
- Silicon chip technology for consistent temperatures
- Can be shelf, wall, or floor mounted
- Compact design fits under sinks
- Only uses energy when hot water is needed
Cons
- Limited to single point-of-use
- 15-amp rating limits flow capacity
- Bracket required for wall mounting
This Chronomite model uses silicon chip technology to deliver pre-set water temperatures without the risk of scalding. It delivers hot water in just 2 seconds compared to the 6 seconds offered by most competing tankless water heaters.
It’s installed for point-of-use applications and is only operational when hot water is requested. This dramatically reduces delivery time and energy waste.
It comes with 98% thermal efficiency and extended-lasting premium glass-lined fabric.
The unit features 12A amps at 120 volts AC for efficient operation. It can be shelf, wall, or floor mounted with the included bracket.
Simply connect to the cold water line and install directly at the sink for on-demand hot water.
These compact units fit neatly below a sink, even in small cabinet spaces. Their sleek design blends in with any existing decor.
This model eliminates long waits for hot water and can supply up to two sinks at a time.
8. Rheem RTEX-18 — Best Digital Control
Rheem 240V RTEX-18 Residential Tankless
The RTEX-18 features an external digital thermostatic control with LED display and +/-1 degree accuracy. Its self-modulation adjusts power to meet hot water demand with a flow rate up to 4.4 GPM.
Pros
- Digital temperature display with +/-1 degree accuracy
- Self-modulating power adjustment
- Durable copper immersion heating elements
- Simple bottom 3/4-inch NPT water connections
- Flow rate up to 4.4 GPM
Cons
- Requires 240V electrical supply
- Professional installation recommended
- Higher upfront cost than basic models
This water heater features an external digital thermostatic control with an LED display providing +/-1 degree accuracy. Its advanced self-modulation adjusts power to meet your hot water demand precisely.
It has durable copper immersion heating elements that are field serviceable. The flow rate reaches up to 4.4 GPM for strong water delivery.
Simple bottom 3/4-inch NPT water connections make installation straightforward.
The threaded connections allow for easy replacement, and the digital temperature display keeps you informed at all times. This water heater is suitable for both residential and commercial purposes.
It comes with a proprietary steel formulation having two coats of high-temperature porcelain enamel which maximizes corrosion resistance. Two heavy-duty magnesium anode rods are installed for longer tank life.
The circulating line connections and hot outlet use 2-inch NPT fittings. Rheem-Ruud industrial storage tanks are vertical tanks designed for applications that need large volumes of hot water in short intervals.
9. Stiebel Eltron — Best Mini Tank
Stiebel Eltron Mini Tank
Stiebel Eltron puts hot water right where you need it with a sleek European design. It features world-class insulation with the lowest standby losses in the industry to save energy.
Pros
- Sleek European design complements any decor
- World-class insulation with lowest standby losses
- Simply plugs into standard outlet
- Minimizes pipe runs to reduce water and energy use
- Available in 3 popular sizes
Cons
- Limited capacity for small applications only
- Not suitable for whole-house use
- Requires plumbing connection
Stiebel Eltron mini tanks are designed to put hot water right where you need it for fast, convenient, water-saving use. The sleek European design complements any decor whether exposed to view or hidden under a sink.
You can plumb the unit with cold water and use it as a standalone hot water supply. You can also connect it with hot water from a remote tank as a buffer to minimize delays.
The SHC always delivers hot water when needed.
All 3 popular sizes simply plug into a standard outlet for easy installation. By putting hot water right where it’s used, pipe runs are minimized and both water and energy use is reduced.
The small tank with its world-class insulation and the lowest standby losses in the industry saves you money all day, every day by reducing energy needs. Stiebel Eltron is known for high-quality products, and the SHC is no exception.
10. Rinnai V Series — Best Longevity
Rinnai V Series HE Tankless Water Heater
Rinnai tankless water heaters recirculate hot water through your pipes for instant access. The compact design fits in non-traditional spaces and has a 20-year average life expectancy.
Pros
- Average life expectancy of 20 years
- Uses 40% less energy than conventional tanks
- Compact design saves 16 square feet of space
- Every part is replaceable for long-term savings
- Recirculates hot water for instant delivery
Cons
- Higher upfront cost than tank models
- Professional installation required
- Gas line connection needed
Rinnai tankless water heaters recirculate hot water through your pipes to get you hot water quickly. If you need a slightly smaller tank, our best 75 gallon water heaters roundup also features Rinnai models. While you wait for hot water to travel from a distant tank to your shower, you can waste a significant amount of water each time.
The compact design allows for installation in non-traditional areas such as the attic, crawl space, or even a closet. Save 16 square feet of space because the Rinnai tankless water heater is only the size of a small suitcase.
A Rinnai tankless water heater will never run out of hot water, and you can trust the brand for all your water heating needs. Your trusted Rinnai service provider can monitor the efficiency of your tankless water heater and address problems before you experience a break in service.
The efficiency packaged in a compact design means reduced CO2 emissions compared to tanks. It uses 40% less energy than conventional tanks because you only heat water when you need it.
Every part of this water heater is replaceable. Parts can be easily swapped without purchasing a completely different system.
The average life expectancy is 20 years compared to 8 to 10 years for a traditional tank. With this premium product, you’ll save both money and worry in the long run.
Frequently Asked Questions
It depends on fuel type and your local rates. Gas models are generally cheaper to run than electric for the same volume. If you go tankless, you could save up to 50% since it only heats water on demand instead of keeping a full tank hot 24/7.
They've got some real advantages — no bulky tank, lower energy bills, and they can last up to 20 years versus 8 to 10 for traditional tanks. The trade-off is a higher upfront cost and you might need electrical upgrades. For most people, the long-term savings are worth it.
With good maintenance, expect 8 to 12 years from a traditional tank model. Tankless units can push 20 years. The key is regular upkeep — flush the sediment buildup and replace anode rods on schedule, and you'll get the most life out of whichever type you choose.
Smaller point-of-use models? Sure, if you're handy with basic plumbing. But larger commercial units and anything gas-powered — definitely call a licensed professional. It's not worth the risk on safety or code compliance.
Final Thoughts
Nobody wants to deal with cold water, especially during winter. And there's no reason you should — the right 100 gallon water heater makes hot water effortless.
The key is matching the heater to your actual needs. Think about capacity, energy efficiency, fuel type, and how much space you have. A tankless unit saves energy and space but costs more upfront. A traditional tank is simpler but takes up a lot of room.
For the best overall value, the Hot Water Heater Jacket Energy improves the efficiency of your existing system by up to 95%. If you want a dedicated tankless unit, the EcoSmart ECO 11 delivers endless hot water while saving up to 50% in energy costs.
