10 Best Immersion Water Heater For Bathtub 2026 in the United States

This portable immersion water heater offers a strong 1800W power rating, which means it heats water quickly, making it a good choice for warming up buckets, bathtubs, and small pools. The heating element uses copper and stainless steel materials, known for durability and efficient heat transfer. Safety is well covered with features like automatic shutoff and dry burn protection, so the heater turns off if it gets too hot or is not submerged properly, reducing risks.

The 78-inch (about 6.5 feet) cord provides decent flexibility for placing the heater in different containers, and the design requires keeping the controller above water for safe operation. Temperature control is a standout feature, with a built-in thermostat allowing you to set the water temperature up to 175°F and a digital display that shows the real-time temperature, helping you achieve the perfect warmth without guesswork. The unit is compact and lightweight, making it easy to move around and store, which is handy if you use it in various locations.

This immersion heater is a practical, efficient, and user-friendly option for anyone needing a portable and safe way to warm water in smaller containers or bathtubs. Since it operates on a standard 120V power outlet, it might not be suitable for larger tubs or pools that need more heating power. Users also need to be mindful to always keep the control unit dry and above water to avoid damage.

The FIVECUBS Portable Water Heater is a compact and lightweight immersion heater offering 2000 watts of power, which is strong enough to quickly warm up to about 5 gallons of water. Its stainless steel heating element is durable and resistant to rust, making it a reliable choice for bathrooms, small pools, or buckets. One of its key safety features is an automatic shut-off system that stops heating once the water reaches 165°F (75°C), helping prevent overheating and scalding risks. The built-in digital thermometer with an LCD screen is a handy addition, allowing you to monitor water temperature easily, which is not always available in similar products.

The heater is designed for use with a standard 110V outlet and comes with clear instructions emphasizing the need to fully submerge the unit to avoid damage or hazards. While the heater is great for smaller volumes of water or portable pools, it might be less efficient for larger bathtubs unless multiple units are used simultaneously. Its relatively small and portable size makes it easy to move and store, ideal for camping or occasional use.

This immersion heater suits anyone needing a quick, safe, and portable water heating solution for small to medium containers. However, it may not fully replace larger, dedicated bathtub heaters intended for bigger volumes.

This immersion water heater is a solid choice if you want to quickly warm water for your bathtub or other uses. It has a strong 1500-watt power rating combined with a durable stainless steel heating element, which means it heats water efficiently and should last a long time. For example, it can warm 5 gallons of water from cool to comfortably warm in just 9 minutes, which is quite fast. Safety is well covered with built-in dry-burn protection that automatically shuts off the heater if it senses abnormal heat, giving peace of mind during use.

The device offers smart temperature control, featuring 14 preset settings and an LED display so you can easily pick and maintain your ideal water temperature between 68°F and 194°F. This precise control is useful whether you prefer a gentle warm soak or hotter water. The heater is compact and lightweight, making it convenient to carry and store, which is great if you use it outdoors or want to save space at home. Its versatility extends beyond bathtubs — it’s also handy for warming water in buckets, for pets, or even small pools.

This immersion heater suits personal or small-scale water heating needs, combining fast performance, safety, and ease of use in a portable design.