Whether you’re upgrading a tired old heater or adding hot water to a bathroom that doesn’t have it, the right bathtub water heater makes all the difference. We’ve reviewed 10 of the best options and broken down exactly what each one offers.
Each review includes quick-reference specs so you can compare without scrolling through pages of text. If you’re looking for a whole-house solution instead, our best electric tankless water heater guide covers full-home options.
The best bathtub water heaters provide instant or maintained hot water with energy-efficient designs. Electric shower head heaters offer the most affordable entry point, while tankless models deliver unlimited hot water. Mini-tank heaters work best as supplemental units near the point of use.
Quick Comparison Chart
| # | Bathtub Water Heater | Our Rating | ||
|---|---|---|---|---|
| 1 |  |
BOCCHERINI Electric | ★★★★★ | Check Price |
| 2 |  |
Whirlpool Massage Tub | ★★★★★ | Check Price |
| 3 |  |
20HI Propane Tankless | ★★★★☆ | Check Price |
| 4 |  |
HOME STUFF Electric | ★★★★☆ | Check Price |
| 5 |  |
ATMOR AT-EJSH-5 | ★★★★☆ | Check Price |
| 6 |  |
Camplux TE04 | ★★★★☆ | Check Price |
| 7 |  |
Stiebel Eltron Tempra 24 | ★★★★☆ | Check Price |
| 8 |  |
Gesail Immersion Heater | ★★★★ | Check Price |
| 9 |  |
Hydro-Quip Bath | ★★★★ | Check Price |
| 10 |  |
Bosch Mini-Tank | ★★★★ | Check Price |
1. BOCCHERINI Electric — Best Overall
BOCCHERINI Electric Instant Hot Water Shower Head
The BOCCHERINI electric shower head provides instant hot water with three power settings for low, medium, and high temperatures. Its automatic sensor turns the unit on and off with the water flow.
Pros
- Three adjustable temperature settings
- Automatic sensor for hands-free operation
- Dual top and handheld shower heads included
- Saves up to 60 percent on water heating costs
Cons
- Requires proper electrical wiring for installation
- Not suitable for extremely cold climates
- Water pressure affects temperature output
This product is excellent for those looking for an instant water heater with unlimited supplies without wasting any energy when not needed.
Three power setting selectors let you control the temperature with low, medium, and high water temperature by adding more or less water.
The showerhead has an automatic sensor that turns on when the water is turned on and turns off when the water becomes off. By buying it you save up to 60 percent on your water heating cost with the Boccherini showerhead heater.
It’s perfect for a tropical country, not cold, not too hot, just perfectly warm.
2. Whirlpool Massage Tub — Best Luxury
Whirlpool Massage Hydrotherapy Bathtub
This two-person whirlpool bathtub features a jet water pump, LCD control panel, LED underwater lights, and FM radio. The built-in heater maintains water temperature throughout your bath.
Pros
- Full hydrotherapy massage with jet system
- LCD control panel for easy adjustments
- LED underwater lighting and FM radio
- Reinforced fiberglass and stainless steel construction
Cons
- Heater maintains but doesn't heat cold water
- Large size requires significant bathroom space
- Professional installation recommended
This product is excellent for those looking to use a jet water pump, LCD control panel, shower stick, water cleaner, and thermostatic faucet. It also includes LED light underwater, Radio FM, Speaker, and padded waterproof Headrests.
The water heater only helps to maintain the water temperature in the bathtub. It has a sensor to sense the water level in the bathtub, and flat legs are at the bottom to make sure stability.
Equipped with massage aircraft and an LED control system, it will add a modern look for the bathroom and relax. This product is bulletproof, and won’t heat cold water.
And it’s made of reinforced fiberglass and stainless steel.
3. 20HI Propane Tankless — Best Gas
20HI Indoor Propane Tankless Water Heater
This 6.0 GPM propane tankless water heater can run a shower and two bathtubs simultaneously. It features an advanced water temperature sensor and a stainless steel construction for long-lasting durability.
Pros
- High 6.0 GPM flow rate for multiple fixtures
- Advanced temperature sensor for safety
- Stainless steel construction
- Ready to install with included power cord
Cons
- Requires propane gas connection
- Indoor venting required for exhaust
- Higher upfront cost than electric models
This product is excellent for those looking for taking a shower and running two bathtubs at the same time. Ready to be installed with the inserted power cord that operates the internal exhaust fan and the digital display with fully automatic control.
It has an incoming, outgoing, and advanced water temperature sensor to sense hot water, so you always have a total feel with safety. Temperatures rise 38 degrees, which is ideal for every single-family home in the US and Canada.
Tankless water heater meets and exceeds all safety and efficiency requirements. Advanced PC board with high-performance processing, smart adjust technology, and automated control system, also it’s made of stainless steel.
4. HOME STUFF Electric Shower — Best Budget
HOME STUFF Electric Shower Head Heater
The HOME STUFF electric shower head features three temperature levels and an automatic on/off sensor. It's made of high-quality polypropylene and connects and disconnects automatically when water flows.
Pros
- Very affordable entry-level price point
- Simple installation with no special tools
- Automatic on/off sensor built into the unit
- Three temperature settings for flexibility
Cons
- Temperature controlled by water flow only
- Lower wattage than premium models
- Best suited for warm climates
This product is excellent for those looking for easy installation, operating, and fully automatically connected and disconnected by simply turning the water on/off.
You can select from 3 temperature levels of water temperature. It’s made of high-quality polypropylene to keep the perfect temperature in the shower, designed with the latest technology, and complete safety of hot water as long as you want.
Water temperature is adjusted by adding more or less water to get the required hot water. The electric shower head contains an automatic on/off sensor integrated into the unit.
5. ATMOR AT-EJSH-5 — Best Wall Mount
ATMOR AT-EJSH-5 Electric Shower Heater
The ATMOR AT-EJSH-5 provides an unlimited supply of hot water with a compact wall-mount design. The complete shower system includes the heater, hose, handheld shower, rise rail, and soap dish.
Pros
- Complete shower system included in one package
- Compact wall-mount design saves space
- Produces hot water in seconds
- Suitable for humid areas
Cons
- Requires dedicated electrical circuit
- Temperature adjusted by water flow rate
- Not ideal for very cold climates
This product is excellent for those looking for an unlimited supply of hot water for your bath, continuity flow of water, also suitable for those who live in humid areas.
Compact design installed quickly on the wall to your shower, includes a water heater. The continuity of the flow of hot water whenever you want without waiting or worrying about running out.
Install it in your bathroom wall, and it’s equipped with an installation wire to easily connect your electricity. It can be ready to produce hot water in a few seconds.
This complete shower system comes with the water heater, hose, handheld shower, rise rail, and soap dish.
6. Camplux TE04 — Best Point of Use
Camplux TE04 Electric Tankless Water Heater
The Camplux TE04 features a rotatable digital temperature screen and intelligent touch controls. It can be mounted at multiple angles and is ideal for kitchens, bathrooms, and compact spaces.
Pros
- Digital temperature display for precise control
- Intelligent touch control panel
- Mountable at multiple angles
- Compact size fits under most bathtubs
Cons
- Lower flow rate than whole-house models
- Requires nearby electrical outlet
- Best as supplemental heater, not primary
This product is excellent for those looking to enjoy electric hot water without a tank. Only heat water when you need it without waiting will only draw the amount of electricity required to produce the boiling water, no need for preheating to save energy and heat.
Enjoy endless instant hot water, remember your preferred temperature, and convert freely for Fahrenheit and Celsius. Tankless water heaters for your shower designed with intelligent touch control and digital temperature screens showing water temperature.
Compact size to save space, ideal for mounting under the bathtub. It can be mounted at multiple angles, ideal for kitchen, wet bars, school, hospital, hair salon, and boats because of its compact size.
7. Stiebel Eltron Tempra 24 — Best Performance
Stiebel Eltron Tempra 24 Plus Tankless Water Heater
The Stiebel Eltron Tempra 24 Plus delivers continuous hot water with advanced flow control and electronic temperature management. It operates silently and features a savings screen that tracks energy costs.
Pros
- Completely noise-free during operation
- Advanced electronic flow control
- Built-in savings screen shows energy costs
- Stable copper interior heating system
Cons
- Higher price point than basic models
- Requires professional electrical installation
- Temperature range limited to 86 to 140 degrees F
This product is excellent for those looking for the continuous flow of water and advanced control of current to maintain water temperature. Tankless water heaters perform with the highest standards for comfort and reliability, automatically maintaining water temperature.
It’s designed to save energy and space, yet it still keeps endless hot water, no need for ventilation, or a water temperature of 86 to 140 F. Ability to electronically measure water flow, a savings screen shows how much you save on energy costs.
Noise-free while in use and has a digital temperature to show the temperature memory button. Electronic flow sensor switches on the powerful, stable copper interior heating system of the water heater.
8. Gesail Immersion Heater — Best Portable
Gesail 1500W Immersion Water Heater
The Gesail immersion heater delivers 1500 watts of heating power with a stainless steel guard that prevents direct contact. It heats water continuously and automatically maintains the set temperature.
Pros
- Fast heating with 1500 watts of power
- Stainless steel guard prevents scalding
- Automatic temperature maintenance
- Plugs into any standard grounded outlet
Cons
- Can't boil water to high temperatures
- Must be fully submerged during use
- Not designed for permanent installation
This product is excellent for those looking for high energy, fast heating water continuously in a few minutes. It can’t boil water.
When the temperature reaches a specific temperature, the immersion heaters automatically turn on/off to maintain water temperature.
Includes a bucket heater that protects the heating element from directly contacting persons or animals. Immerse in the water at a proper level.
Plug into any grounded wall outlet. Check the power indicator light in the plug to make sure the water bucket heater is on.
It’s perfect for the winter period. Also, it saves time and energy.
They’re made of stainless steel guards to prevent scalding of hands.
9. Hydro-Quip Bath Heater — Best Compact
Hydro-Quip Bath Heater
The Hydro-Quip bath heater features an automatic smart thermostat factory set to 104 degrees and a high-temperature limit circuit for safety. Its compact design fits easily into tight spaces.
Pros
- Automatic smart thermostat with factory preset
- High-temperature limit circuit for safety
- Compact space-saving design
- Heater ON indicator light
Cons
- Limited to maintaining existing water temperature
- Factory thermostat setting may need adjustment
- Not suitable for primary water heating
This product is excellent for those looking for a space-saving water heater and small to maintain shower water. The automatic smart thermostat (factory set to 104).
Smart circle to reduce a high-temperature heater control vacuum and pressure switch (pressure and vacuum activities model). Intelligent High-temperature Limit Circuit, Made of Stainless Steel.
Heater “ON” Indicator Light.
10. Bosch Mini-Tank — Best Mini-Tank
Bosch Tronic 3000 T Mini-Tank Water Heater
The Bosch Tronic 3000 T stores 4 gallons of hot water and delivers it on demand. It features a glass-lined interior for long service life and can supply up to two fixtures simultaneously.
Pros
- Fast recovery eliminates long waits for hot water
- Glass-lined interior for extended service life
- Shelf, wall, or floor mountable
- Supplies up to two fixtures simultaneously
Cons
- Limited to 4 gallons of stored hot water
- Requires cold water line connection
- Larger than tankless alternatives
This product is great for those looking for a water heater that fits your bathtub to save hot water where you need it. Use an electric water heater to get hot water when it’s required, it fits easily under a sink, even in a cabinet space.
This electric water heater is easy to maintain and has premium glass-lined material for long service life. Fast recovery of the heater to get hot water without long waiting and worrying about running out means it eliminates long waits for hot water at your sink.
Easily control temperature by external disc. It supplies up to 2 baths at the same time.
Easily mounted: can be shelf, wall, or floor mounted (bracket included). Simply tap into the cold water line and install the water heater directly at the sink to provide hot water.
How We Evaluated
We evaluated each bathtub water heater based on several key criteria to make sure our recommendations are thorough and reliable.
Heating Performance
We assessed how quickly each unit heats water and whether it maintains consistent temperatures. Electric shower heads were tested for their instant heating capabilities, while tankless models were evaluated on flow rate and temperature rise.
Energy Efficiency
Energy savings are a major factor for bathtub water heaters. We compared wattage, standby energy loss, and overall efficiency.
Models that only heat water on demand scored higher than those with continuous energy draw.
Installation and Ease of Use
We considered how simple each unit is to install and operate. Products with plug-and-play setups or included installation hardware received higher marks.
Units requiring professional installation were noted accordingly.
Build Quality and Safety
Durable construction materials like stainless steel and reinforced fiberglass were prioritized. Safety features including automatic shutoff, temperature limit circuits, and grounding protection were all factored into our ratings.
Value for Money
We weighed each product’s features and performance against its price point. Budget-friendly models that deliver solid performance scored well, while premium models needed to justify their higher cost with superior features.
Buying Guide: Choosing the Best Bathtub Water Heater
Choose the one that works for you according to your needs. Here are the key factors to consider before making your purchase.
Type of Water Heater
There are several types of bathtub water heaters available. Electric shower head heaters provide instant hot water and are the most affordable option.
Tankless water heaters offer unlimited hot water on demand. Mini-tank models store a small amount of hot water near the point of use.
Whirlpool tubs with built-in heaters maintain water temperature during long baths.
Power Source
Consider whether you want an electric or gas-powered water heater. Electric models are easier to install and work well in most climates.
Propane tankless heaters deliver higher flow rates but require gas connections and proper venting. If you have a tankless unit, consider pairing it with a battery backup for tankless water heaters for uninterrupted hot water during outages.
Temperature Control
Look for models with adjustable temperature settings. Three-setting models (low, medium, high) offer basic control, while digital display models provide precise temperature adjustments.
Some units remember your preferred temperature setting.
Installation Requirements
Some bathtub water heaters simply plug into a standard outlet, while others require dedicated electrical circuits or professional plumbing. Consider your existing infrastructure and whether you’re comfortable with DIY installation before choosing a model.
Size and Mounting
Space is often limited in bathrooms. Compact wall-mount units save floor space, while under-sink mini-tanks stay hidden.
Consider the available mounting options and the physical dimensions of each unit relative to your bathroom layout.
Frequently Asked Questions
It really comes down to how you use your bathtub. Tankless electric heaters are great for instant hot water and save space. Whirlpool tubs with built-in heaters keep the water warm during long soaks. And mini-tank models work well as a supplement to your existing system.
Yes, as long as the unit has a handheld shower attachment. These heaters warm the water instantly as it flows through and let you adjust the temperature to whatever feels comfortable.
It varies by model. Electric shower head heaters pull between 1500 and 5500 watts. The nice thing about tankless models is they only draw power when water's actually flowing, which can save you 20 to 60 percent compared to keeping a tank hot all day.
They can be, as long as you follow the rules. Look for models with stainless steel guards and automatic shutoff. Always make sure the heater is fully submerged before you plug it in, and never walk away while it's running.
Final Thoughts
There's no single best bathtub water heater for everyone. It really comes down to your bathroom setup, your budget, and what matters most to you.
If you want instant hot water with minimal fuss, the BOCCHERINI electric shower head is hard to beat. Looking for a luxury bathing experience? The whirlpool massage tub turns your bathroom into a spa. And for reliable, whole-bathroom hot water, the Stiebel Eltron Tempra 24 delivers.
Just make sure whatever you choose fits your electrical setup and the space you've got. A little planning goes a long way.
