APUS Tankless Water Heater Review: Honest Pros & Cons

If you are looking to replace a bulky tank water heater or upgrade your home’s hot water system, you have likely encountered the growing popularity of tankless units. The promise of endless hot water on demand is appealing, but choosing the right model requires careful consideration of your household’s needs. This APUS tankless water heater review takes an in-depth look at the 190,000 BTU propane model, examining its features, performance claims, and overall value to help you decide if it is the right fit for your home.

We analyze the specifications, build quality, and real-world use cases of this whole-home unit, comparing it to similar products on the market. Whether you are a homeowner dealing with a large family or a DIY enthusiast planning an outdoor installation, this review provides the honest, detailed information you need before making a purchase.

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What Is the APUS 190,000 BTU Outdoor Tankless Water Heater?

The APUS 190,000 BTU Outdoor Tankless Water Heater (model AP-AWH-W26LPG) is a propane-powered, on-demand water heater designed for whole-home use. Rated at 8.1 gallons per minute (GPM), it aims to supply hot water simultaneously to multiple fixtures like showers, faucets, and appliances. Unlike traditional storage tank heaters that maintain a reservoir of hot water, this unit heats water only when needed, which can lead to energy savings and a continuous supply of hot water.

This model is intended for outdoor installation, which saves indoor space and eliminates the need for venting through the roof or walls. It is equipped with smart features, including Wi-Fi control via the Tuya Smart app and a wired remote controller, allowing users to adjust temperature settings from 95°F to 149°F with a claimed accuracy of ±1°F. The unit runs on liquid propane (LP) gas and requires a 120V AC electrical connection for its electronics and fan.

APUS positions this heater as a solution for medium to large households, claiming it can support up to five outlets simultaneously—for example, three showers and two faucets. With a low minimum flow rate of 0.79 GPM, it is also designed to activate even under weak water pressure conditions, making it suitable for rural areas or homes with older plumbing.

Key Features & Specifications

The APUS tankless water heater comes packed with features that aim to combine efficiency, durability, and convenience. Below is a breakdown of its main attributes and specifications.

The whole-home hot water capability is a central selling point. APUS states that the heater can supply 3 showers plus 2 faucets running simultaneously, which would cover the peak demand of a typical 4-5 person household. The smart temperature control via the Tuya app allows users to change settings remotely, which is convenient for pre-heating before a shower or adjusting temperature for different uses.

The advanced heat exchanger uses 100% oxygen-free copper, which the manufacturer claims is 30% more efficient than conventional water heaters. Combined with intelligent staged combustion technology, this is said to deliver 20% energy savings. While these figures are manufacturer estimates, the use of copper heat exchangers is generally associated with better heat transfer and longer life compared to less expensive materials.

For outdoor installations, the all-weather performance features are important. The 10-level wind rating and electric anti-freeze protection are designed to keep the unit operating in harsh conditions, including strong winds and freezing temperatures. The complete safety protection includes freeze protection, overheat protection, and flame failure safeguards, which are standard for modern gas appliances.

What’s Included in the Box

When you purchase the APUS tankless water heater, the box contains the following items:

• Tankless water heater unit (pre-assembled)
• Wired remote controller with mounting bracket (optional use)
• Controller cable (length not specified)
• Mounting screws and wall anchors (6 pieces each)
• Expandable screw
• Closed circuit terminals (for electrical connection)
• Installation and owner’s manual

Notably, the package does not include a gas shut-off valve, water shut-off valves, or the venting materials (though this unit typically requires outdoor installation, some local codes may still require proper clearance). Users will need to supply their own 120V outlet nearby, a suitable propane gas line with a regulator, and water supply lines (standard 3/4″ NPT connections).

Setup is designed to be straightforward for those with basic plumbing and electrical experience, but a licensed professional is strongly recommended for gas line connections and final commissioning to ensure safety and code compliance.

How to Use the APUS Tankless Water Heater

Setup

Installation begins with selecting an outdoor location with adequate clearance from windows, doors, and combustible materials. The unit must be mounted on a wall using the included screws and anchors, ensuring it is level. Connect the 3/4″ water lines (cold water inlet and hot water outlet) and the 3/4″ gas line from your propane supply. A 120V AC outlet is required for the electronic control board and fan. After all connections are tightened and leak-checked, turn on the gas supply and power. The initial startup may require bleeding air from the gas line. Consult a qualified installer if you are unsure about any step.

Operation

Once installed, the unit operates automatically when a hot water tap is opened. The flow sensor detects water movement and ignites the burner to heat the water to the set temperature. You can adjust the temperature using the wired remote controller or via the Tuya Smart app on your smartphone. The app also allows you to monitor the unit’s status, set schedules, and adjust settings remotely. The temperature range is 95°F to 149°F in 1-degree increments. The unit features smart seasonal technology that adjusts combustion for optimal efficiency based on incoming water temperature.

Maintenance

To maintain performance, periodic maintenance is recommended. This includes flushing the heat exchanger with a descaling solution (e.g., white vinegar or commercial descaler) every 6-12 months, especially if you have hard water. Check the air intake and exhaust for debris or obstructions. The water filter inlet should be cleaned regularly. The manufacturer recommends annual inspection by a qualified technician to ensure safe operation.

Troubleshooting

Common issues include failure to ignite (check gas supply, bleed air from line, ensure no blockages in the burner), fluctuating water temperature (may be due to undersized gas line, incorrect gas pressure, or simultaneous high demand), and error codes displayed on the controller (refer to the manual). If the unit does not activate at low flow, the minimum flow rate of 0.79 GPM may still be too high for very low-flow fixtures – in that case, a recirculation pump or reducing aerator may help. For persistent problems, contact APUS customer support.

Performance & User Experience

Based on the manufacturer’s claims and standard performance expectations for a 190,000 BTU propane tankless water heater, here is what users can realistically expect.

The 8.1 GPM rating is a theoretical maximum for a specific temperature rise. Typically, a tankless heater’s flow rate decreases as the temperature rise increases. For example, to raise groundwater from 50°F to 120°F (a 70°F rise), the unit might deliver around 4-5 GPM, which is still sufficient for two showers running simultaneously. For a 40°F rise (e.g., 60°F to 100°F), it could achieve near its rated 8.1 GPM. Users in colder climates with colder incoming water should expect reduced output. The manufacturer does not provide a temperature rise chart, so it is wise to calculate your household’s peak demand using a tankless sizing calculator.

The smart app control adds a layer of convenience. The Tuya platform is widely used for smart home devices, and the app is generally reliable for setting temperatures and scheduling. However, like all Wi-Fi-connected appliances, the user experience depends on your home network’s reliability. Some users have reported occasional connection drops, but overall the app functionality is a strong plus.

The low minimum flow rate of 0.79 GPM is a notable advantage. It means the heater can activate even with a small demand, such as a single bathroom faucet, without requiring a high flow rate. This makes it suitable for homes with low water pressure or older plumbing that may not deliver high flow.

Regarding outdoor performance, the 10-level wind rating is a significant feature. Many tankless heaters are susceptible to wind-related flame failure, but APUS claims this unit can withstand strong gusts. The electric anti-freeze protection is also important for cold climates, preventing the heat exchanger from freezing when the unit is idle. Note that anti-freeze protection requires the unit to have power; a power outage could leave it vulnerable.

Overall, based on specs, this heater should meet the needs of a medium-sized household (2-3 bathrooms) in moderate climates, with some limitations in colder regions or for very high simultaneous demand.

Pros and Cons

Pros

• High flow rate (8.1 GPM) suitable for multiple simultaneous uses under moderate temperature rise conditions.
• Smart connectivity with Tuya app and wired remote for easy temperature adjustments.
• Low minimum flow rate (0.79 GPM) allows operation with low water pressure or small faucets.
• Outdoor design saves indoor space and simplifies venting.
• Rugged weather protection with wind rating and anti-freeze.
• Oxygen-free copper heat exchanger offers good heat transfer and durability.
• Comprehensive safety features including freeze, overheat, and flame failure protection.
• 2-year warranty provides peace of mind.

Cons

• Propane-only model – not convertible to natural gas without a conversion kit (check availability).
• Requires 120V electrical connection – may not be an option for off-grid installations without power.
• Flow rate drops with colder incoming water – performance in northern winters may be less than advertised.
• No included gas line or shut-off valves – additional purchase and installation costs.
• App connectivity can be intermittent depending on Wi-Fi router.
• Limited user reviews available (only 42 at time of writing) – long-term reliability data is scarce.
• Warranty is industry-average – some competitors offer longer coverage.

Comparison With Alternatives

The APUS 190,000 BTU heater competes with other popular tankless water heaters in the same performance tier. Below is a comparison with two well-known alternatives.

Note: Electric models are included for comparison but differ significantly in installation requirements and running costs. The APUS is better suited for whole-home high-demand applications where electric models may struggle due to power supply limits.

Other gas competitors include Rheem’s RTG-199XL (199,000 BTU) and Takagi T-KJR (180,000 BTU). Rheem offers a higher BTU output and longer warranty (3 years) but lacks smart control. Takagi is known for reliability and also has a 2-year warranty. The APUS differentiates itself through its smart app and low minimum flow activation.

Compare APUS with other tankless water heaters on Amazon

Who Should Buy This Product?

Ideal Users

• Homeowners with a medium to large household (3-5 people) needing consistent hot water for multiple showers and faucets.
• Those already using propane (e.g., for cooking, heating) who can connect the heater to an existing propane line.
• Homeowners in mild to moderate climates looking for an outdoor unit that can withstand occasional wind and freeze events.
• Tech-savvy users who appreciate the convenience of smartphone control and scheduling.
• DIYers with basic plumbing and electrical skills who want to install the unit themselves (though gas line work should be professional).
• Anyone replacing a failing tank heater and wanting to save indoor space.

Not Ideal Users

• Households in very cold climates with groundwater temperatures below 40°F, as the flow rate will be significantly lower than 8.1 GPM.
• Those without access to a reliable 120V outlet near the installation site.
• People who prefer a natural gas model (the APUS is propane-only).
• Users who need a unit that can be installed indoors (this unit is outdoor-rated only).
• Homeowners with very high simultaneous demand (e.g., 4+ showers running) – this unit may not keep up in winter.
• Those who are not comfortable with smartphone apps and prefer a simple mechanical thermostat.

Expert Tips

To get the most out of your APUS tankless water heater, consider these practical recommendations:

• Properly size your gas line. The 190,000 BTU unit requires a gas line capable of delivering sufficient flow. Consult a professional to ensure your propane line and regulator are adequate; undersized lines can cause low pressure and poor heating.
• Install a whole-house water softener if you have hard water. Mineral buildup can reduce the efficiency and lifespan of the heat exchanger. Regular descaling is still necessary, but a softener reduces frequency.
• Test your incoming water temperature. Use a thermometer to measure the cold water line in winter. This helps you estimate the actual temperature rise and set realistic expectations for flow rate.
• Use the app for energy savings. Schedule lower temperatures during times when hot water is less needed (e.g., overnight) to save gas.
• Ensure proper ventilation. Even though the unit is outdoor-rated, it should not be installed in a confined space like a small alcove that could trap exhaust gases. Follow clearances in the manual.

Common Mistakes

1. Undersizing the gas line. Using a 1/2″ pipe when a 3/4″ is needed can cause insufficient gas flow, leading to poor performance and error codes.
2. Installing without a drip leg (sediment trap). A drip leg in the gas line catches debris and prevents it from entering the burner assembly.
3. Ignoring the outdoor rating. Installing the unit in a location that does not allow proper air intake and exhaust clearance can cause overheating or recirculation of exhaust gases.
4. Not flushing the system before first use. New plumbing or old pipes may contain debris that can fould the water filter and flow sensor.
5. Setting temperature too high. Temperatures above 125°F can cause scalding, especially for children and elderly. Use the default 120°F and adjust only as needed.
6. Assuming it can run without electricity. This unit requires 120V to operate; a power outage means no hot water.
7. Neglecting to register the warranty. Register your product with APUS to activate the 2-year warranty and receive support.

Where to Buy

The APUS 190,000 BTU Outdoor Tankless Water Heater is available from several online retailers, but the most straightforward option is through Amazon. Purchasing through Amazon often provides easy returns, customer reviews, and potentially faster shipping. Given that this is a relatively new model, buying directly from Amazon ensures you receive the latest version and full warranty support.

Before making a purchase, verify that the model (AP-AWH-W26LPG) matches your propane setup. You may also find it at specialty home improvement stores or through the manufacturer’s website, but availability may vary.

Final Verdict

The APUS 190,000 BTU Outdoor Tankless Water Heater offers a compelling package for households seeking a propane-powered, smart-controlled whole-home solution. Its high flow rate, low minimum activation, and weather-resistant construction make it a strong contender in the mid-range tankless market. The addition of Tuya smart app control adds modern convenience that many competitors lack at this price point.

However, buyers must be realistic about its performance in colder climates, and the propane-only nature may limit its appeal for some. The relatively new market presence—only 42 reviews at this writing—means long-term reliability data is not yet abundant. That said, the 2-year warranty and use of oxygen-free copper suggest a reasonable build quality.

Overall, if your home uses propane and you are looking for an outdoor tankless heater with smart features, this APUS model is definitely worth considering. Just be sure to properly size your installation and understand the limitations regarding cold water temperature. For many households, it will provide years of reliable, on-demand hot water.

Check the latest price and availability of the APUS tankless water heater

Frequently Asked Questions (FAQ)

Can this unit be used with natural gas?

The model AP-AWH-W26LPG is specifically designed for liquid propane (LP) only. Using natural gas without an approved conversion kit may damage the unit and void the warranty. Check with APUS if a natural gas conversion kit is available for this model.

What is the actual flow rate in summer vs. winter?

The flow rate depends on the temperature rise needed. In summer when incoming water is warmer (e.g., 70°F), you can achieve near the rated 8.1 GPM for a 100°F output. In winter with 40°F incoming water, a 120°F output requires an 80°F rise, likely reducing flow to around 4-5 GPM. Performance will vary based on your local groundwater temperatures.

Do I need a permit to install this outdoor tankless heater?

Local building codes vary. Most jurisdictions require a permit for gas line work and possibly for the water heater installation itself. Always check with your local building department before installation. Failure to obtain necessary permits could affect your home insurance and safety.

How loud is the unit during operation?

Like most tankless gas heaters, the APUS produces a moderate amount of noise from the burner and fan. Typically, it is comparable to a gas furnace, not silent but not excessively loud. Installation away from windows and bedrooms helps minimize any disturbance.

Does it have a recirculation pump built-in?

No, this unit does not include an internal recirculation pump. If you need instant hot water at distant faucets, you would need to install an external recirculation system or a dedicated recirculation pump with a bypass valve.

What does the 2-year warranty cover?

APUS offers a 2-year full warranty on all components. This covers defects in materials and workmanship. It does not cover damage from improper installation, misuse, or lack of maintenance. You must register the product to activate the warranty. Read the terms carefully.

Can I install this unit myself?

While the water and gas connections are relatively straightforward, we highly recommend hiring a licensed plumber and gas fitter for the gas line connection and initial startup. Incorrect gas installation can lead to leaks, fire, or explosion. Electrical work (if new outlet needed) should also be done by a qualified electrician.

How does the smart app work?

Download the Tuya Smart app (available for iOS and Android). Pair the water heater via Wi-Fi (2.4 GHz network required). Once connected, you can adjust temperature, view usage logs, set schedules, and receive error notifications. The app is generally user-friendly but may require occasional re-pairing.

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