best outdoor tankless water heaters

7 Latest Best Outdoor Tankless Water Heaters Reviewed 2023

Looking for the best outdoor tankless water heater? Right on, you are covered. 

Having a tankless water heater is already a luxury and having an outdoor model at that is the best thing. There’s no need to build expensive venting for flue gases, no worries of flooding damage due to leakage and you save precious indoor space. Meaning cost savings and peace of mind. 

So what’s stopping you? I have done all the research and gone through comparing more than 13+ models to help you shop for the best outdoor tankless unit. 

Below, I have selected the 7 best outdoor tankless water heaters all of which are either natural gas or propane-powered. Yes, there’s no electric-powered water heater that is waterproof and freezes protected. If you need an electric water heater then go here and install it inside.

REVIEWS: 7 best outdoor tankless water heater 

1. Navien NPN-199E outdoor tankless water heater

Navien NPN-199E
  • Activation flow: 0.5 GPM
  • Max flow: 9.5 GPM
  • Input: 199.00 BTU
  • Fuel: natural gas/propane
  • Energy factor: 0.81 UEF

The first one on our list is the Navien NPN series, 199E model. Specifically designed for outdoor wall installation, the unit requires no special venting pipeline or anything. It has a 3×5 side opening to vent flue gases.

This non-condensing tankless water heater can be sourced with either propane or natural gas and has a consumption capacity of upto 199k BTUs per hour. Along with that, it has typical 0.81 UEF energy efficiency. 

As for the flow rate, you can expect a 9.5 GPM maximum flow rate in the warm climates of Florida which drops as we further move towards the north region. In a freezing climate, expect somewhere 2-3 GPM flow rate. There are low-powered variants available including 160E and 180E for smaller families.

Navien NPN features complete stainless steel construction with its specially made dual stainless steel heat exchanger that is said to be robust and efficient. The unit is test-certified for low NOx emission. 

  • Robust stainless steel buildnLow NOx emissionsnUpto 9.5 GPM flow rate n
  • Average energy efficiency and no EnergyStar certificationn

2. Rheem performance plus outdoor tankless water heater

Rheem performance plus outdoor tankless water heater
  • Activation flow: 0.4 GPM
  • Max flow: 9.5 GPM
  • Fuel: natural gas/ propane
  • Input: 160,000 BTUs
  • Energy efficiency: 0.81 UEF

Next up on our list is the popular American brand, Rheem. This performance plus series outdoor tankless water heater can deliver upto 9.5 GPM hot water at a 35°F rise range which is more than enough for large families. It also comes in smaller variants including 8.5 and 7 GPM. 

The Rheem is available in both natural gas and liquid propane options. It has a high input of 160,000 BTUs which varies based on the size you choose and has an energy efficiency of 0.81 UEF across all sizes. 

It features a special ultra-low NOx emission burner that meets CAQM standards. Rheem is providing upto 12years of warranty on the heat exchanger and 1 year on the whole unit and labor. The unit can be controlled with digital wired remote control. 

If we go by the EnergyGuide, the Rheem performance plus costs approximately $228 in average annual energy cost. 

  • High-quality build that’s durablenA decent flow rate of upto 9.5 GPMnLow NOx emission means eco friendlynUpto 12-year warranty on heat exchangern
  • None foundn

3. Eccotemp 45H-LP best outdoor propane tankless water heater

  • Activation flow: 0.8 GPM
  • Max flow: 6.8 GPM
  • Fuel: natural gas/propane
  • Input: 150,000 BTUs
  • Energy factor: 0.8

Eccotemp is a rather new brand in the water heating industry but it’s making the name for itself by providing a range of affordable appliances. 

One such appliance is Eccotemp 45H-LP, an outdoor tankless water heater. Equipped with complete stainless steel construction, the unit exhausts flue gases from the side vent. It requires no special venting construction and is simpler to install on the wall.

The unit has maximum hot water output of upto 6.8 GPM and near 2.5 GPM in cold climates where you can expect to run a shower and a sink simultaneously. 

Speaking of fuel, both liquid propane and natural gas variants are available. The unit features an energy factor of 0.8 which means it’s 80% energy efficient. That said, you get a 10-year warranty on the heat exchanger which in my opinion 5 years shorter than the industry standard.

  • Decent hot water output of 6.5 GPM for small familiesnUpto 10-year warranty on heat exchangernBoth natural gas and propane variants are availablen
  • A lot of complaints about issues with the flame sensor which might cause trouble in the smooth operation of the unit.n

4. Rinnai V53DeN outdoor tankless water

  • Activation flow: 0.5 GPM
  • Max flow: 5.3 GPM
  • Fuel: Natural gas
  • Input: 120,000 BTUs
  • Energy efficiency: 0.81 UEF

If you are looking for the brand trust and reliability of Rinnai then the model V53DeN is perfect for you. The natural gas-fired unit has a decent energy efficiency of 0.81 UEF and input consumption of upto 120k BTUs per hour. 

It has a nominal activation flow rate of 0.5 GPM and a top-line flow of 5.3 in the hot weather of Florida. You can expect a 2.5 GPM flow in the climates of Alaska or Minnesota. The unit is quite popular among its users for its durability and consistent service. 

As per EnergyGuide estimates, the Rinnai V53DeN costs roughly $149 on average annual gas cost. The appliance is wifi supported, meaning you can remotely control it using voice command but that’s an additional component and is sold separately. 

That said, you will get upto 10 years of warranty on the heat exchanger.

  • Upto 5.3 GPM flow rate ideal for medium size familyn0.81 UEF energy efficiencynWifi supportednUpto 10-year warranty on heat exchangern
  • No propane variant is available n

5. Fogatti 4.5 GPM outdoor tankless water heater

  • Activation flow: 0.7 GPM
  • Max flow: 4.5 GPM
  • Fuel: Natural gas/ propane
  • Input: 180,000 BTUs
  • Energy efficiency: 0.81 UEF

Next up in our list of best outdoor tankless water heaters is the Fogatti which is a rather new brand but making quite a name for it. 

The 4.5 GPM model is sufficient for a family of 3-4 as it can run two showers and multiple sinks simultaneously.

Fogatti is available in both fuel variants; natural gas and propane. It consumes upto 180k BTUs per hour and has an energy factor of near 0.80. 

The model is specially designed for outdoor installation. It comes with waterproof, wind protection, and antifreeze protection. So whatever may be the weather outside, your heating unit will be safe and operating. 

As per the energy guide, the unit consumes approximately $223 worth of energy annually on average. 

Fogatti comes with easy to use remote control with a good 25 ft length of wire. 

  • Ideal for 3-4 people family nBudget-friendly pricenEasy to operatenConsistent hot water deliveryn
  • Warranty information is not clearnRather new brandn

6. Takagi TH3J-OS-N condensing outdoor tankless water heater

  • Activation flow: 0.7 GPM
  • Max flow: 6.6 GPM
  • Fuel: Natural gas
  • Input: 160,000 BTUs
  • Energy efficiency: 0.95 UEF

If you are looking for a more efficient outdoor tankless option than standard then you should consider Takagi. The TH3J is a condensing tankless water heater that’s at least 15% more efficient than all the other units on this list, which means you save 15 cents more on every dollar spent on gas. It’s EnergyStar certified model but sure it’s comparatively expensive. 

The Takagi model is a natural gas-fired unit with a hot water flow of upto 6.6 GPM in warm climates. Expect near 2.5 GPM in cold regions of the North. 

It is a complete freeze and waterproof appliance and provides robust service. The unit equips Low NOx emission to ensure a minimal carbon footprint. With Takagi, you get upto a 15-year warranty on its copper heat exchanger. 

However, I would like to point out an issue with this model. A lot of people are complaining about noisy operations.

  • Highly energy efficient at 0.95 UEFnConsistent hot water deliverynLow NOx emission outputnUpto 15 year warrantynEnergyStar certifiedn
  • Makes noise while operatingn

7. GasLand BE158 portable tankless water heater for outdoor use

  • Max flow: 1.58 GPM
  • Fuel: Propane
  • Input: 41000 BTUs

Gasland BE158 is the perfect solution for outdoor hot water needs. Whether it’s camping, beach, or RV where you need to take a hot shower, or give your animals at the barn a relaxing hot bath, the Gasland covers it all. It has a 1.58 GPM flow that’s enough for a soothing shower. Just make sure the incoming water pressure is at least 2.5 PSI. 

The easy-to-install and in fact, hangable unit is quick to use and comes with a showerhead as well. The unit has a complete set of protections in place, including antifreeze and overheat protection. 

Gasland runs on liquid propane fuel and consumes 41000 BTUs per hour. Its sophisticated burner makes minimal burning noise. You can say it has a silent operation. 

So all in all, if you are looking for a portable water heating solution that you can use outdoors and wherever you go then Gasland is perfect for you. 

  • Upto 1.5 GPM hot water flownPortable design that can be carried wherever you gonLiquid propane-powerednAntifreeze and overheat protectionn
  • One of the issues with this unit is it starts to cause issues if not used for a prolonged period. n

Pros and cons of outdoor tankless water heater


Before you commit to an outdoor tankless water heater or any other system it’s better to first know about all their pros and cons. Also, learn about the pros and cons of tankless water heaters.

Pros of outdoor heater

  • Outdoor tankless water heaters are ideal for warm climates. While these units come with antifreeze, waterproofing, and all kind of protection but they can sometimes be susceptible to moisture in freezing climates
  • One of the best parts about outdoor units is saving expensive indoor space that can be used for other things. 
  • Tankless water heaters are prone to condensation and leakages which can destroy your flooring. But with this unit installed outside, there’s no such worry. 
  • Also, there can be the noise of gas burning during operation which can be heard and can be disturbing to noise-sensitive people. Hopefully, you won’t hear it with outdoor water heaters. 
  • NOx is a colorless and toxic gas that gas water heaters emit. If the unit is inside and there’s the absence of proper ventilation then you risk gas poisoning. You don’t have to worry about that when the unit is outside
  • Since outdoor tankless water heaters are installed outside, there’s no need of building expensive venting for the flue gas we talked earlier about. So money savings

Cons of outdoor heater

  • First, outdoor units can be more expensive than their indoor counterparts partly thanks to the antifreeze, waterproofing, and all other outdoor protection that it comes with. 
  • All this outdoor weather protection is electric-powered so if you have a power outage then this protection is lost as well. So outdoor units are at risk of weather damage and freezing in areas with a frequent power outages. This guide help winterize your tankless unit.
  • Also, there’s always a risk of theft of the unit since it’s outside. Thieves can still the precious copper components or unhook the whole unit if you live in a theft-prone locality. Try to place it in a more protected or less visible location. 
  • All outdoor units are gas-powered which are prone to fast scale build-up. Which implies frequent flushing and maintenance.

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