Best 40 Gallon Gas Water Heaters in 2025

On demand a continuous and unlimited supply of hot water

Sleek design saves space and no venting required, It also features two different temperature memory presets, making it easy to adjust for personalized needs.

Requires hard-wired 240 or 208-volt electric service, with a maximum draw of 28,800 watts at 240 volts or 21,600 watts at 208 volts

External adjustable digital thermostatic control with LED display (+/1 degree accuracy

Durable Copper immersion two heating elements, field Serviceable.Self-modulating power control

Simple installation – 1/2 NPT adapters included; side 1/2 inch Compression water connections

Original Design: Tankless hot water heater only heats when necessary to conserve energy; For the latest in non-condensing technology and a cleaner layout that speeds up service and installation, check out our new RE160eN model

Never Run Out of Hot Water with this Compact Tankless Gas Water Heater: Non-condensing tankless hot water heater from Rinnai is only the size of a small suitcase and fits in a wide variety of spaces, but provides up to 6.5 GPM (5 fixtures at once)

Smart, Durable Design: Enhanced scale detection helps prevent serious, long-term damage to unit; Includes 15-, 5-, and 1-year residential guarantee for heat exchanger, labor, and parts, respectively; See Controlr module for WiFi control (not included)

HOLDRITE WATER HEATER RESTRAINT STRAPS: Water heater earthquake/seismic restraint kits secure your water heater in the event of seismic activity

WHAT IS INCLUDED: The QuickStrap system includes (4) straps, (2) J-clips, (2) 3/8 inch carriage bolts, and (2) 3/8 inch hex nuts

CAPACITY: This galvanized steel strap supports water heaters up to 80 gallons and features the QuickLink system which allows for full adjustment from the front side of the water heater

Lightweight, Compact & Portable Design: The 10 pounds lightweight portable water heater's folding handle keeps it out of the way and enables easy setup outside.

Flow Rate & Temperature Specification: The temperature raise is 114.8℉ (46℃) at its highest point and 46.4℉ (8℃) is at its lowest point of 1.32 GPM. Also, 1.32 gallons of hot water can be produced per minute at the flow rate of 1.32 GPM.

Versatile Applications: The lowest water pressure at beginning for the water heater is 3.0 PSI. For off-grid and rural areas, this hot water generator powered by two size D batteries is ideal. No more chilly outdoor shower anymore.

Endless Hot Water: Enjoy unlimited hot water flow throughout the house; compact, durable, and easy to install; professional installation recommended

Energy and Space Efficient: Space-saving design conserves energy as it heats only when necessary

Optimal Water Pressure: High-performance up to 5.3 GPM hot water flow rate for a powerful, constant stream

MULTIPLE BENEFITS: Extend the lifetime of your water heater, improve its efficiency, reduce your energy bill, and increase your hot water supply. This tool pays for itself in one use!

WORKS GREAT: tradition flushing only removes small loose sediment particles where the Turbo Tank Cleaner works to break up the large sediment deposits collected at the bottom of the tank.

UNIVERSAL: cleans all water heater tank types, gas and electric (not for tankless water heaters).

Endless hot water

Can be vented with Schedule 40 PVC Pipe and Fitting

High Efficiency

Installation Guide. We recommend that all installations must in accordance with the local building and plumbing codes of the installation location, install the hot water heater by a licensed professional plumber.

Instant Hot Tankless Water Heater. Camplux advanced 6.86 GPM high capacity natural gas tankless water heater delivers 6.86 gallons per minute of on-demand endless hot water. It is suitable for 3-4 outlet points, which can satisfy whole family.

Easy Installation. It won't take up your indoor space, keeping your home more airy and having a more comfortable living experience. The tankless water heater includes digital remote control with a 3.3 feet cable for convenient flow control.

ON/OFF Dial Control with adjustable digital temperature display

Self-modulating power control

24kW Model Flow Rate: up to 5.9 GPM for RTEX-24

No more waiting for the water tank to warm up or running out of warm water halfway through your shower. With this amazing machine, you can have a steady stream of hot water flowing to your faucets or shower without waiting for the tank to warm up.

There is a forced exhaust structure that keeps the air safe and clean while and after entering the combustion chamber. There is also a dust net to make sure no dirt gets into the tankless water heater.

There is a low water pressure startup, which helps to protect the heater and make it easier to use.

[No Wait for Hot Water] - Point of use 1.3 gallons mini tank water heater provides instant hot water where you need it with fast recovery, reducing standby loss. Thermal efficiency up to 99%

[Small Compact for Sink] - The hot water heater is compact designed for your sink with dimensions 11.42" x 11.42" x 9.65", can be wall or floor mounted under sink / counter, plug into a standard 120V outlet. Nominal current 12amps

[Adjustable Temperature] - Thermostat with 3 temperature level settings, range from 77°F to 140°F with high temperature limit protection, also a freeze mode to prevent tank from freezing

𝟮.𝟲𝟰𝗚𝗣𝗠/𝟭𝟬𝗟 𝗣𝗿𝗼𝗽𝗮𝗻𝗲 𝗪𝗮𝘁𝗲𝗿 𝗛𝗲𝗮𝘁𝗲𝗿 - Maximum power output 68,000BTU/Hr.The temperature raise is 109.4℉ (43℃) at its highest point and 55.4℉ (13℃) is at its lowest point of 2.64 GPM. Also, 2.64 gallons of hot water can be produced per minute at the flow rate of 2.64 GPM. Low water pressure start up, just need 3.6 PSI of water pressure to start.

𝗚𝗼𝗼𝗱 𝗳𝗼𝗿 𝗢𝗳𝗳-𝘁𝗵𝗲-𝗚𝗿𝗶𝗱 - Runs on a standard 20 lb. liquid propane tank and is equipped with an electronic ignition powered by two D-cell batteries. Can be used in a variety of scenarios: while you're camping, RVing, hunting, hanging poolside, washing your pets or horses, cleaning your vehicle, or even in your tiny home, greenhouse, or cabin house.

𝗔𝗱𝘃𝗮𝗻𝗰𝗲𝗱 𝗦𝗮𝘁𝗲𝗳𝘆 𝗣𝗿𝗼𝘁𝗲𝗰𝘁𝗶𝗼𝗻 𝗦𝘆𝘀𝘁𝗲𝗺 - With CSA certification, safe as per Canadian and US Standard. Features over-heating protection, low water flow protection, dry combustion protection, anti-freezing protection, high water pressure protection and flame failure device.

☼ Endless Hot Water: Imagine you are the last one in your family to take a shower before heading out for the day. You turn on the faucet and the water is freezing cold. Too bad you don’t have an Airthereal Electric Tankless Water to provide endless hot water on demand with no preheating, temperature fluctuations, or running out of hot water in the tank.

☼ Save Space: That water heater in the basement or utility closet takes up a ton of space. This wall-mounted water heater uses 90% less space than a traditional hot water heater with a tank.

☼ Save Energy: Water is only heated when you need it, not stored in a hot water tank. The self-modulating temperature technology only uses energy to heat up water while you are using it to save up to 50% on water heating costs compared to a typical tank water heater.

ON/OFF Dial Control with adjustable digital temperature display

Self-modulating power control

8kW Model Flow Rate: up to 1.95 GPM

【MULTIPLE PROTECTIONS】：HOTaitai propane tankless water heater can automatically shuts off gas supply when flame goes out accidentally and ignition is unsuccessful. Anti-freezing protection, the drain plug can discharge the residual water inside to avoid freezing in cold areas or in case of long time idle. This portable water heater has high temperature protection, if water temperature over 167 °F, the unit will shut down automaticlly.

【QUICK CONNECT GAS INLET】: Easy to install gas pipe by one hand, with more safety for preventing any gas danger at the same time. And this portable propane water heater has compact size and folding handle allow for convenience to carry. With the portable handle, you can hanging it vertically into a hook or using the mounting bracket on the top/back of the gas water heater.

【CSA CERTIFIED】：The gas quick fittings-CSA approved, to make sure no gas leaks risk when connection and simplify the connection without tools, install by one hand.

【2000W Ultra Fast Heating】2000W immersion water heater heats up faster. When you're out camping or traveling, the high-power travel bucket water heater can quickly heat up 5 gallons of water in minutes, saving you time and power consumption.Faster than 1500W immersion water heater.

【Easy to Operate】The design of the submersible portable water heater is simple. Small size, easy to carry when you travel, (How to use: Please make sure the immersion heater is fully immersed in water, and then connect the 125v/110v power supply. Equipped with a digital LCD thermometer, after heating for a period of time, put the probe into the water to test the water temperature.)

【Upgrade Design】2000W High power Immersion heater adopts a stainless steel protective shell, with a solid structure, high bending strength, and very safe. Below the protective hole, the heat is released faster. The bottom drainage design adopts high-temperature and wear-resistant material to drain to prevent accidental injury.

【1500W Powerful & Safety Protection】The 1500W pool heater for above ground can heat up five gallons of water in minutes.The thermostat control of pool heater will turn on or off circularly and automatically to maintain the water temperature when water temperature reaches a certain level.

【Rust Proof 304 Stainless-steel Guard】This above ground pool heater power cord is made of PVC skin which is not easy to leak. The quality is safe and stable. The bottom drainage design adopts high-temperature and wear-resistant material for drainage, which is not easy to melt and prevent accidental damage. The immersion heater adopts a stainless steel protective shell which has a solid structure and high bending strength. Below the protective hole, the heat is released faster.

【Smaller Size & Portable Use】The pool water heater is small in size and easy to carry during travel, heating 5 Gallons of Water in Minutes Bucket Heater (How to use: Please make sure the immersion heater is fully immersed in water, and then connect the 120v/110v power supply. Equipped with a digital LCD thermometer, after heating for a period of time, put the probe into the water to test the water temperature.)

Gas Type: LPG Liquid Petroleum Gas (PROPANE), Capacity: 18L/min (4.8Gal), 25 degrees warm water producing rate.

Working temperature:-8-45℃, Thermal input: 36KW, Thermal efficiency: ≥80.8%. Temperature rise: 25℃.

Automatic ignition system, Flame failure protection device, Water & gas combination unit ,Fitted with over heating and pressure safeguard, Suitable for both summer and winter.

【Smaller size and better performance】It is only 1/4 the size of a 50 gallon tank water heater, yet it produces approximately 4.0 GPM of hot water through 90,000 BTU for both bathroom and kitchen hot water demand. The highly integrated components also provide greater safety from water pressure surges without the need to install an expansion tank.

【Fast and endless supply of hot water】The heat exchanger quickly heats the water to a maximum of 140℉ in a short time, and the hot water is quickly piped through to the shower and tap. No need to wait for the water temperature to heat up slowly like a tank water heater. After that it continues to operate at approximately 4.0 GPM for 40 minutes, which is enough time to produce almost 160 gallons of hot water.

【Stable and comfortable temperature】Benefiting from the calculation and control of the heating power 1000/s by the chip, the temperature difference of the water can be precisely controlled within ±2°F.

CSA Certified

LED Touch Screen Computerized Safety

Flow activation

Exclusive Water Savings technology conserving up to 1, 100 gallons per year

157, 000 BTU (gas consumed per hour)

Exclusive Hot Start Programming minimizes cold water burst by staying in ready-fire state

Hot water without the wait - or the waste

Low operating cost - High energy efficiency and water savings setting

Space Savings - Compact, space-saving design. Perfect for a tank replacement.

Hot water without the wait - or the waste

Low operating cost - High energy efficiency and water savings setting

Space Savings - Compact, space-saving design. Perfect for a tank replacement.

APPLICATION: Dimensions : 20.25" W x 49.14" H x 20.25" L. Perfect size for a maintenance closet, access closet under the stairs, crawl space. Ideal for replacement projects.

DURABILITY: Two magnesium anode rods for extra tank protection. Dielectric heat trap. Heavy gauges steel tank for extra years of trouble-free service. Glass-lined steel tank to help prevent corrosion.

WARRANTY: 10-year tank and parts limited warranty

SAFE & PREMIUM:With high quality stainless-steel protect cover,will effectively prevent the heating element is in direct contact with people or animals ，it is rust proof and durable, design for long term use.Our immersion water heater has an intelligent temperature control design, which automatically cuts off the power when the water temperature reached 75℃. The quality is safe, stable and reliable, preventing dry burning.

FAST HEATING:1500W of power can make 5 gallons of water warm in a few minutes.Heat dissipates to the water faster by flowing through the holes in the guard.The heater needs to be completely immersed in water in working condition.Please take out the immersion water heater before touching the water! Do not use it for more than 3 hours continuously! Please do not plug the two heaters into the same outlet to avoid fire hazards.

WIDE RANGE OF APPLICATIONS:Our portable water heater is suitable for portable bathtub,mini pool(Using more than one),sink, bucket, washbasin,etc.Make sure the container can hold hot water when using it.This immersion heater is handy and super lightweight, making it perfect for travels and road trips.Note, only for water heating.

Instant Sufficient Hot Water: The electric tankless water heater applied with 4.5KW heating system supplies sufficient instant and endless hot water in seconds, no waiting for preheating while bathing. Ideal for use with shower, sink faucet, dishwasher or washing machine. (Product comes with a shower head, outlet pipe and a set of installation accessories)

Digital Control Panel: The tankless electric water heater is equipped with digital display and touch control panel, you can easily control the temperature through the control panel, while the information displayed on the screen can help you fully understand the working status of the water heater, you can easily make the corresponding operation.

Multiple Protection: The safety of the product is always the first priority. This tankless water heater has an over-temperature protection design: when the outlet water temperature reaches over 131F/55C, the electricity will be automatically cut off to avoid getting scalded and the screen will display E1, And then the water heater will start to work automatically while the temperature drops to the set temperature.

【16L Tankless Water Heater】TCFUNDY Tankless water heater with compact design saves more space and energy efficient than traditional water heaters. LCE screen with digital temperature display and touch screen control. There are 3 modes you can choose: eco mode, common mode, tub mode.

【On-Demand Instant Water Heater】High efficiency natural Gas tankless water heater delivers 4.23 gallons per minute of on-demand endless hot water. No more waiting for long time, instant hot water for families, homes, cabins or apartments.

【Thermostatic & Energy Saving】Water heater built-in high-precision thermostat ensures constant temperature, high-thermal efficiency up to 90%. The self-modulating temperature technology only heat up water while you are using it to save energy.

Bradford White ICON System

Advanced ScreenLok Technology Flame Arrestor Design

Resettable Thermal Switch

Continuous Hot Water – never run out of hot water, even with back-to-back showers

Tankless Gas Water Heaters are cost saving and energy efficient

Reduces Energy Consumption - Automatically adjusts the amount of energy required to heat the water you need