Eemax Tankless Water Heater Review 2026: Does It Really Work?
Are you tired of running out of hot water during your morning shower? You stand there shivering while waiting for the tank to heat up again.
Traditional water heaters waste energy heating water you don’t need. Eemax tankless water heaters solve this problem by providing instant hot water whenever you need it. These compact units heat water on demand and can save you money on energy bills.
This review explores the best Eemax tankless water heaters available on Amazon. You will discover which models work best for your home.
Key Takeaways
- Endless Hot Water Supply: Eemax tankless water heaters provide continuous hot water by heating it on demand, which means you never run out during back-to-back showers or while running multiple fixtures.
- High Energy Efficiency: These units operate at 99% efficiency, heating only the water you actually use and eliminating standby heat loss that traditional tank heaters suffer from, potentially saving you hundreds on annual energy bills.
- Compact Space-Saving Design: Eemax heaters are 90% smaller than traditional tank water heaters, mounting easily on walls and freeing up valuable floor space in your utility room, basement, or garage.
- Long Lifespan: With proper maintenance, Eemax tankless water heaters are designed to last up to 20 years, significantly longer than traditional tank heaters that typically need replacement after 10-12 years.
- Multiple Power Options: The Eemax lineup includes models ranging from 3.5 kW to 36 kW, with both 120V and 240V options suitable for everything from single-sink point-of-use applications to whole-home water heating solutions.
- Self-Modulating Technology: Many Eemax models feature smart self-modulating capabilities that automatically adjust power consumption based on water flow and desired temperature, optimizing both performance and energy usage.
Understanding Eemax Tankless Water Heater Technology
Eemax tankless water heaters use electric heating elements to warm water instantly as it flows through the unit. The technology works differently than traditional tank heaters.
When you turn on a hot water tap, cold water travels through the heater and copper heating elements warm it instantly. This process happens in seconds and continues as long as you need hot water.
The electric tankless design offers several advantages. You get hot water immediately at the point of use. The unit only heats water when you need it, which cuts energy waste dramatically.
These heaters run at 99% efficiency because nearly all the electricity goes directly into heating water. Traditional tank heaters constantly reheat stored water, leading to standby losses that waste energy and money.
Eemax units feature self-modulating technology in many models. This smart feature adjusts power output based on water flow rate and incoming water temperature.
Eemax EEM24013 Electric Tankless Water Heater
The Eemax EEM24013 stands out as one of the most popular models on Amazon with excellent customer ratings.
This 13 kW unit operates on 240 volts and delivers hot water for point-of-use applications. The compact design measures just 11.5 inches high by 8 inches wide, making it perfect for installation under sinks or in small utility spaces.
This model provides approximately 2.4 gallons per minute at optimal conditions. You can run one shower comfortably in warmer climates, or heat water for a single sink in colder regions.
The self-modulating technology adjusts power based on flow rate, ensuring consistent temperature. The stainless steel heating elements resist corrosion and last longer than standard copper elements.
Installation proves straightforward for licensed electricians. The unit requires a 60-amp breaker and 6 AWG wiring. The compression fittings simplify water connections.
Many homeowners report installation takes just a few hours. The digital temperature display lets you monitor settings easily. You can adjust temperatures to your preference without complicated controls.
Eemax HomeAdvantage II HA027240 Whole-Home Solution
The Eemax HA027240 represents the HomeAdvantage II series designed for residential whole-home applications.
This powerful 27 kW unit operates on 240 volts and delivers substantially more hot water than smaller models. The system can provide hot water for multiple fixtures simultaneously, making it suitable for larger households.
This model delivers approximately 5.4 gallons per minute depending on inlet water temperature. You can run two showers at once in moderate climates.
The unit features hand-welded stainless steel construction that ensures durability. The brass-topped copper immersion heating elements are easily replaceable, extending the lifespan of your investment.
The HomeAdvantage II series includes advanced features. The self-modulating capability maintains consistent temperatures automatically.
The digital controls offer precise temperature management from 80°F to 140°F. The unit requires 112.5 amps at 240 volts, so professional installation is essential. Most installations need upgrades to electrical service to handle the power requirements.
Top 3 Alternatives for Eemax Tankless Water Heater
Eemax SPEX3512 FlowCo Point-of-Use Heater
The Eemax SPEX3512 FlowCo serves a specific purpose in the product lineup. This 3.5 kW unit operates on standard 120-volt household current, making it accessible for simple installations. The FlowCo series targets handwashing and fixed-flow applications rather than full shower heating.
This non-thermostatic heater works differently than self-modulating models. It heats water at a fixed rate based on flow. The unit delivers approximately 0.5 to 1.0 gallons per minute of temperature rise depending on incoming water temperature. This makes it perfect for bathroom sinks, utility sinks, and commercial handwashing stations.
The compact design measures only 9.5 inches high and 5 inches wide. You can install it directly under a sink cabinet. The unit weighs just 3 pounds, simplifying mounting. Installation requires only a standard 120V outlet and basic plumbing connections. Many homeowners complete installation themselves following local codes.
Eemax HA008240 Compact 8 kW Model
The Eemax HA008240 fills the gap between point-of-use heaters and whole-home systems. This 8 kW unit operates on 240 volts and provides more heating power than the EEM24013 but requires less electrical capacity than larger models. The compact gray housing fits into tight spaces while delivering reliable performance.
This model provides approximately 1.5 to 2.0 gallons per minute depending on inlet water temperature and desired output temperature.
You can comfortably heat water for one shower in warmer climates. The unit works excellently for workshops, pool houses, and small apartments. Installation requires a 40-amp breaker and appropriate wiring.
The straightforward design emphasizes reliability. The unit includes standard features like adjustable temperature controls and activation at low flow rates.
The housing measures approximately 12 inches high by 9.75 inches wide. Wall-mounting hardware comes included. Professional installation is recommended to ensure proper electrical connections and compliance with local codes.
Eemax HA036240 Maximum Power for Large Homes
The Eemax HA036240 represents the top of the residential line with an impressive 36 kW power rating. This 240-volt unit delivers the maximum hot water capacity for demanding households. Families with multiple bathrooms and high hot water usage find this model meets their needs effectively.
This powerhouse provides approximately 7 gallons per minute in moderate climates. You can run three showers simultaneously or mix shower and appliance use without temperature drops.
The massive heating capacity handles even the coldest inlet water temperatures. The unit measures 17 inches high by 14 inches wide, larger than other models but still significantly smaller than tank heaters.
The electrical requirements are substantial. The HA036240 requires 150 amps at 240 volts. Most homes need electrical panel upgrades to support this unit.
Professional installation by a licensed electrician is absolutely necessary. The installation cost often exceeds the unit price, so budget accordingly. The payback comes through years of reliable hot water and energy savings.
Energy Efficiency and Cost Savings
Eemax tankless water heaters deliver remarkable energy efficiency compared to traditional tank systems. The 99% efficiency rating means almost every dollar you spend on electricity goes directly into heating water. Traditional tank heaters waste energy through standby losses as stored water gradually cools and requires reheating.
The on-demand heating approach eliminates this waste completely. The unit sits dormant consuming zero energy until you open a hot water tap.
The average household saves 30% to 50% on water heating costs by switching from tank to tankless systems. For a typical family spending $400 annually on water heating, savings reach $120 to $200 per year.
The self-modulating technology in many Eemax models enhances savings further. The system reduces power consumption automatically when you need less hot water.
If you’re washing hands instead of showering, the unit uses proportionally less electricity. This intelligent adjustment maximizes efficiency across all usage patterns.
Long-term cost benefits extend beyond monthly utility bills. Eemax heaters typically last 20 years compared to 10-12 years for tank heaters. The longer lifespan means fewer replacement costs over time.
Installation Requirements and Considerations
Proper installation is crucial for optimal Eemax tankless water heater performance. Electrical requirements vary significantly based on model power rating.
The 120-volt FlowCo models plug into standard outlets, while larger 240-volt units need dedicated high-amperage circuits. Always hire a licensed electrician familiar with local electrical codes.
The smaller 13 kW models typically require 60-amp breakers with 6 AWG copper wire. Mid-range units need 80 to 100 amps. The largest 36 kW models demand 150-amp circuits.
Your electrical panel must have sufficient capacity to support the heater plus other household loads. Many installations require panel upgrades, especially in older homes with 100-amp or 150-amp main services.
Water connections prove simpler than electrical work. Most Eemax units feature standard 3/4-inch NPT connections. Professional plumbers recommend using flexible connectors for easier installation.
The units mount directly to wall studs using included hardware. Ensure adequate clearance around the unit for service access. Manufacturers specify minimum distances from walls and other obstructions.
Maintenance and Troubleshooting Tips
Eemax tankless water heaters require minimal maintenance compared to tank systems. The most important maintenance task is descaling in areas with hard water.
Mineral buildup on heating elements reduces efficiency and can cause premature failure. Flush the system annually using manufacturer-approved descaling solutions or white vinegar.
The descaling process is straightforward. Turn off power and water to the unit. Connect a pump to the service valves if equipped, or remove inlet and outlet connections.
Circulate descaling solution through the unit for 45 minutes to an hour. Flush thoroughly with clean water before returning to service. This annual maintenance extends heater life significantly in hard water areas.
Filter maintenance prevents sediment from entering the heater. Install a sediment filter on the inlet line if your water contains debris. Check and clean filters every six months. Clogged filters restrict flow and reduce performance. The simple maintenance task takes just minutes but prevents costly repairs.
Choosing the Right Size Eemax Water Heater
Selecting the correct Eemax model requires understanding your hot water demands. Calculate the maximum gallons per minute you need by adding up simultaneous fixture flows. A standard shower uses 2.0 to 2.5 gallons per minute, sinks use 0.5 to 1.5 gallons per minute, and washing machines use about 2.0 gallons per minute.
Consider your climate’s impact on heating requirements. Cold inlet water requires more power to reach comfortable temperatures. Groundwater temperatures vary from 40°F in northern winters to 70°F in southern summers.
This 30-degree difference dramatically affects the kilowatt rating you need. A 13 kW heater that provides 2.5 gallons per minute with 65°F inlet water might only deliver 1.5 gallons per minute with 40°F water.
Eemax provides sizing charts that factor in inlet temperature and desired flow rate. For point-of-use applications like single sinks, 3.5 to 8 kW models work well. Bathrooms with one shower need 13 to 18 kW units. Whole-home heating for families requires 24 to 36 kW depending on simultaneous fixture use and climate.
Eemax vs Traditional Tank Water Heaters
The comparison between Eemax tankless and traditional tank heaters reveals clear advantages and some tradeoffs.
Tankless heaters provide endless hot water while tanks run out and require recovery time. Large families particularly appreciate never waiting for the tank to reheat between showers. The tankless design eliminates the frustration of cold showers.
Energy efficiency strongly favors tankless technology. Traditional tanks maintain 40 to 80 gallons of water at temperature constantly.
Standby heat loss wastes energy even when nobody uses hot water. Eemax heaters consume zero energy while idle. The 99% operational efficiency far exceeds the 60% to 70% efficiency of standard tank heaters.
Space requirements differ dramatically. A traditional 50-gallon tank heater measures about 60 inches tall and 24 inches wide.
Eemax tankless units are 90% smaller and mount on walls. The space savings allow installation in locations impossible for tank heaters. Many homeowners install tankless heaters in bathrooms, laundry rooms, or even closets near fixtures.
Real User Experiences and Customer Reviews
Customer feedback reveals important insights about Eemax performance in real-world conditions. Thousands of verified Amazon purchasers have shared detailed reviews.
The EEM24013 model maintains a solid 4.4-star rating across hundreds of reviews. Users consistently praise the instant hot water delivery and compact installation size.
Positive reviews highlight several common themes. Customers love the endless hot water supply that eliminates waiting for tank recovery. Many reviewers mention significant energy bill reductions after switching from tank heaters.
The compact size receives frequent praise, particularly from RV owners and tiny home builders. Installation simplicity impresses DIY-capable homeowners who complete projects themselves following manufacturer guidelines.
Critical reviews provide valuable warnings about limitations. Some customers express disappointment when units fail to meet expectations in very cold climates. Performance depends heavily on proper sizing for your specific needs and location.
Environmental Impact and Sustainability
Eemax tankless water heaters align well with environmental sustainability goals. The elimination of standby heat loss reduces overall energy consumption significantly.
Lower energy use translates directly to reduced carbon emissions from power generation. For households powered by coal or natural gas electricity, the carbon footprint reduction can reach 30% to 50% compared to traditional tank heaters.
The long 20-year lifespan reduces manufacturing waste compared to replacing tank heaters every 10 years. Fewer water heater replacements mean less metal mining, processing, and transportation pollution.
The compact size also requires fewer raw materials during manufacturing. Eemax units contain recyclable copper, brass, and steel components.
Water conservation represents another environmental benefit. Traditional tank heaters waste substantial water while users wait for hot water to travel from distant tanks.
Point-of-use Eemax installations deliver hot water within seconds, minimizing water waste down the drain. For a household that saves just 5 gallons daily from reduced waiting time, annual water savings exceed 1,800 gallons.
FAQs
How often should I descale my Eemax tankless water heater?
Descaling frequency depends on water hardness in your area. Homes with hard water should descale annually. Water with less than 7 grains per gallon hardness can go 2 years between descaling. Very hard water areas might benefit from descaling every 6 months. Contact your water utility to learn your local water hardness level.
Signs that descaling is overdue include reduced flow rate, longer heating times, and fluctuating water temperatures.
Mineral buildup on heating elements acts as insulation, reducing efficiency. The unit works harder to achieve set temperatures, wasting energy. Regular descaling maintains peak performance and extends heater lifespan significantly.
Can I install an Eemax tankless water heater myself?
Installation capability depends on the model and your skills. Small 120-volt FlowCo models are DIY-friendly for capable homeowners. These units plug into standard outlets and require only basic plumbing connections. Always follow manufacturer instructions and local building codes. Obtain required permits if your jurisdiction mandates them for water heater installations.
Larger 240-volt models require professional installation by licensed electricians. The high-amperage circuits present serious shock and fire hazards if installed incorrectly. Most building codes require licensed electrician certification for 240-volt installations. The electrical work typically costs $500 to $1,500 depending on wire run length and panel upgrade requirements.
What size circuit breaker does my Eemax heater need?
Circuit breaker sizing depends on your specific Eemax model’s amperage requirements. Manufacturers specify the exact amperage in product documentation. As a general rule, select a breaker rated 25% higher than the unit’s maximum current draw. This safety margin prevents nuisance trips during normal operation.
Small models like the EEM24013 draw about 54 amps and require 60-amp breakers. Mid-range 18 kW units need 80-amp breakers. The powerful HA027240 requires a 125-amp breaker, while the HA036240 demands 150 amps. Wire gauge must match breaker capacity. A 60-amp circuit needs 6 AWG copper wire, while 150-amp circuits require 1/0 AWG copper.
Do Eemax tankless heaters work in cold climates?
Eemax heaters work in cold climates but require proper sizing. Cold inlet water temperatures significantly reduce the gallons per minute you can heat. A 13 kW unit that provides 2.5 gallons per minute with 65°F inlet water might only deliver 1.5 gallons per minute when inlet temperature drops to 40°F. The heater must raise water temperature more degrees, requiring more time and energy per gallon.
Cold climate installations often need higher kilowatt ratings than similar applications in warm regions. A bathroom that needs 13 kW in Florida might require 18 or 24 kW in Minnesota. The extra power compensates for colder inlet temperatures. Consult Eemax sizing charts that factor in your region’s groundwater temperatures for accurate model selection.
How long do Eemax tankless water heaters typically last?
Eemax designs their tankless heaters to last up to 20 years with proper maintenance. This lifespan doubles the typical 10 to 12 years for traditional tank heaters. The absence of a storage tank eliminates corrosion issues that cause tank failures. The replaceable heating elements allow component-level repairs rather than complete unit replacement.
Actual lifespan varies based on water quality and maintenance. Hard water areas that neglect annual descaling see significantly shorter lifespans. Mineral buildup damages heating elements and other components. Proper maintenance extends life expectancy to the full 20-year design period or beyond. Some well-maintained Eemax units continue operating effectively after 25 years.
