Table of Contents

Introduction

If you’re shopping for a tankless water heater that can handle the demands of a busy household while offering modern conveniences like remote control and app connectivity, you’ve likely come across the APUS 190,000 BTU outdoor model. This unit promises whole-home hot water delivery with up to 8.1 gallons per minute (GPM), enough to run multiple showers and faucets at the same time. But does it live up to the hype? In this APUS 190000 BTU tankless water heater review, we’ll dig into the features, real-world usability, and potential drawbacks to help you decide whether this propane heater is worth the investment. Before we dive in, if you want to check the latest customer feedback and detailed specs, you can see the APUS propane water heater on Amazon for more details. —

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

The APUS 190,000 BTU Outdoor Tankless Water Heater (model AP-AWH-W26LPG) is a propane-powered, wall-mounted unit designed for whole-home, on-demand hot water. It delivers up to 8.1 GPM of hot water, making it suitable for homes with moderate to high simultaneous water use—like running three showers and two faucets at once, according to the manufacturer. Unlike traditional tank heaters that keep water hot 24/7, this tankless system heats water only when you need it, which can lead to energy savings. It’s designed for outdoor installation, freeing up indoor space, and includes both a wired remote and WiFi control via the Tuya smart home platform. The unit is rated for outdoor use with wind resistance and electric anti-freeze protection, so it can operate in harsh weather conditions. It’s important to note that this model runs on liquid propane (LP) only; a natural gas version is available separately. —

Key Features & Specifications

Performance Specifications

Specification	Value
BTU Output	190,000
Flow Rate (GPM)	8.1
Minimum Flow Rate	0.79 GPM
Temperature Range	95°F – 149°F
Temperature Accuracy	±1°F
Power Source	120V AC
Gas Type	Liquid Propane (factory set)
Dimensions (W x H x D)	6.54 x 22.48 x 15.51 inches
Mount Type	Wall-mount

Notable Features

Whole-Home Capacity: 190,000 BTU and 8.1 GPM to handle up to 3 showers + 2 faucets simultaneously, per the manufacturer.
Smart Temperature Control: Adjust temperature via the wired remote or Tuya smart app. The unit maintains a stable ±1°F temperature, which is precise for tankless heaters.
Compact Outdoor Design: Measures only 6.54 inches deep, making it easy to install on an exterior wall without taking up usable space.
Advanced Heat Exchanger: Uses 100% oxygen-free copper, which the company claims is 30% more efficient than standard heat exchangers, and intelligent staged combustion for 20% energy savings.
All-Weather Performance: Engineered with wind resistance up to level 10 and electric anti-freeze protection, so it can operate in cold, windy environments.
Safety Protections: Includes freeze, overheat, and flame failure safeguards, plus a 2-year full warranty on components.

The ability to start heating at a very low flow rate (0.79 GPM) means the water heater can activate even when only a single faucet is turned on, which is helpful in homes with low water pressure. However, the actual activation threshold may vary depending on your home’s plumbing and temperature rise requirements.

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What’s Included in the Box

Based on the product listing, the APUS tankless water heater ships with the following items:

Tankless water heater unit (pre-set for propane)
Wired remote controller with cable (optional installation)
Controller mounting screws and closed circuit terminals
Installation and owner’s manual
Expandable screw, wall anchors, and mounting screws

Note that the remote controller is included but its use is optional—you can also control the unit entirely through the Tuya app if you prefer wireless operation. The manual should provide clear instructions for both installation and initial setup. Because this is a gas appliance, professional installation is strongly recommended (see the “Common Mistakes” section below).

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How to Use the APUS Tankless Water Heater

Setup

Mounting and connecting the APUS unit requires careful attention to gas, water, and electrical connections. According to the manufacturer, the heater uses standard 3/4-inch NPT water and gas connections. It must be connected to a 120V AC power outlet (standard household outlet) to operate the control board and anti-freeze protection system. The unit is designed for outdoor installation, so it should be placed on a wall that can support its weight and be properly vented (the unit is direct-vent, but outdoor installation typically negates the need for a flue).

Important: Because this is a propane gas appliance, hiring a licensed plumber and gas fitter is essential for safe installation. Improper setups can lead to gas leaks, fire hazards, or carbon monoxide risks.

Operation

Once installed and powered on, the APUS heater operates automatically when a hot water tap is opened. The flow sensor detects water movement and triggers the burner to heat the water instantly. You can adjust the target temperature either by pressing buttons on the wired remote (if you chose to mount it) or through the Tuya smart app on your phone. The app also allows you to monitor usage and set schedules if needed. The temperature range is 95°F to 149°F, and the unit claims to hold the set temperature within ±1°F.

Maintenance

Routine maintenance is minimal but important for long-term performance. The manufacturer recommends periodically flushing the heat exchanger with a descaling solution (white vinegar or a commercial descaler) to remove mineral buildup, especially if you have hard water. Frequency depends on water hardness—every 6 to 12 months is common. Additionally, you should inspect the air intake and vent for debris, and check for any gas leaks around connections. The unit’s self-diagnostic system will alert you to error codes, which are explained in the manual.

Troubleshooting

Common issues include the heater not igniting (check gas supply and power), reduced flow (possible mineral scale or a clogged filter), or temperature fluctuations (often due to incorrect flow rate or pressure changes). The manual includes a troubleshooting chart. If the unit displays an error code, note the code and refer to the manual or contact APUS support. For persistent problems, contacting a qualified technician is the safest route.

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Performance & User Experience

The APUS 190,000 BTU water heater is marketed as a whole-home solution, and based on its specs, it has the potential to supply multiple fixtures simultaneously. With 8.1 GPM, it can handle up to three showers (each using roughly 2.0-2.5 GPM) plus a couple of faucets, provided the incoming water temperature isn’t too cold. In colder climates, the temperature rise (the amount the heater can warm the water) becomes a limiting factor. A 190,000 BTU propane heater can typically raise the water temperature by about 50-60°F at 8.1 GPM. If your groundwater is very cold (e.g., 40°F), you may need to reduce flow to achieve a comfortable 110°F shower temperature. This is common for all tankless heaters.

As of the writing of this review, the product has accumulated 42 customer ratings with an average of 4.3 out of 5 stars. Many users praise the compact size and the convenience of the WiFi remote control. Some mention that the app setup was straightforward. However, a few reviews note that the unit can be noisy when the burner is running, and that the WiFi connection can be intermittent if the heater is far from the router. Since outdoor installation often places the heater away from the main house, signal strength may be a real consideration.

The smart staged combustion technology is said to deliver 20% energy savings over standard water heaters. While this is a manufacturer claim, it aligns with the general efficiency of tankless systems compared to tank heaters. Real-world savings will depend on your usage patterns and utility rates. The 100% oxygen-free copper heat exchanger is a high-end component that should resist corrosion better than some alternatives, potentially extending the unit’s lifespan.

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Pros and Cons

Pros

High flow rate (8.1 GPM) suitable for moderate to large households
WiFi and remote control offer convenient temperature management
Compact, low-profile design for outdoor mounting
Low minimum flow rate (0.79 GPM) helps activation with low water pressure
Weather-resistant construction with wind rating and anti-freeze protection
100% oxygen-free copper heat exchanger for durability
2-year full warranty on components

Cons

Propane-only model; natural gas version sold separately
Requires 120V AC power – won’t work during a power outage
WiFi performance may be affected by distance from home router
Outdoor installation only; not suitable for indoor use without venting kit
Some users report noise during operation
Customer reviews are still limited (42 ratings at time of writing)
Professional installation required (adds to overall cost)

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Comparison With Alternatives

To put the APUS model in context, here’s how it compares with a few well-known tankless water heaters in a similar BTU class.

Feature	APUS 190,000 BTU	Rheem RTG-199DV	Rinnai RL94i
BTU	190,000	199,000	199,000
GPM	8.1	8.4	9.4 (varies by temperature rise)
Gas Type	Propane only (natural gas version available)	Propane or Natural Gas (dual certified)	Propane or Natural Gas (dual certified)
Smart Control	Tuya App + wired remote	Built-in WiFi (EcoNet app)	Wired remote (WiFi module optional)
Installation	Outdoor only	Outdoor or Indoor with vent kit	Outdoor or Indoor with vent kit
Warranty	2 years	5 years heat exchanger; 1 year parts	5 years heat exchanger; 1 year parts

Rheem and Rinnai are established brands with longer warranties and wider compatibility (indoor/outdoor, dual gas). The APUS offers competitive specs at a typically lower purchase price, but with a shorter warranty. If you value brand reputation and a proven track record, the alternatives might be worth considering. However, if you’re looking for a budget-friendly outdoor propane solution with smart features, the APUS is a strong contender.

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Who Should Buy This Product?

Ideal Users

Homeowners who already use propane and want an outdoor tankless heater
Households with 2-4 people and moderate simultaneous hot water demand
Those who prioritize smart home integration and app-based temperature control
People with adequate exterior wall space for mounting
Budget-conscious buyers seeking a high-BTU unit without paying for a premium brand

Not Ideal For

Homes with very cold groundwater that requires a high temperature rise (may need to restrict flow)
Those who want an indoor installation without extra venting
Users who prefer a natural gas connection (separate model needed)
Large families with high simultaneous water use (5+ people) – may want 199,000 BTU or higher
Anyone who cannot arrange professional installation

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Expert Tips

Size the unit correctly. Use a tankless sizing calculator to determine the required GPM based on your peak simultaneous usage and groundwater temperature. The 8.1 GPM rating assumes a 35°F temperature rise; your needs may differ.
Install a whole-house sediment filter. This protects the heat exchanger from debris and reduces mineral scaling, extending the life of the unit.
Flush the system annually. Even if the manufacturer says every 6-12 months, hard water areas benefit from more frequent descaling. Use a pump and white vinegar or a commercial descaler.
Optimize WiFi placement. If the heater’s outdoor location is far from your router, consider a WiFi extender or mesh network to maintain a stable connection for the Tuya app.
Check the gas line size. A 190,000 BTU propane heater requires an adequate gas supply line. A smaller line may cause insufficient gas flow, leading to poor performance. Consult a professional.

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Common Mistakes

Ignoring the minimum flow requirement. At 0.79 GPM, this heater can run on low-pressure systems, but if your home has very low flow (e.g., 0.5 GPM), it may not activate. Test your faucets’ flow rates first.
Undersizing for cold climates. If your incoming water temperature is below 50°F, the unit may not reach your desired output temperature at full flow. You may need to lower the flow rate or choose a higher BTU unit.
Installing without a gas shutoff valve nearby. Local codes typically require a visible gas valve; ensure your installer includes one for safety and maintenance.
Using undersized T&P (temperature and pressure) relief valve. The heater comes with a T&P valve, but if you replace it, use one rated for the heater’s output.
Neglecting grounding. The 120V AC connection must be properly grounded to avoid electrical shock or damage to the control board.
Forgetting to register the warranty. Many warranties require online registration within a set period. Do it immediately after installation to ensure coverage.

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Where to Buy

The APUS 190,000 BTU tankless water heater is available through online retailers, with the most common source being Amazon. For the most current information, including stock availability and customer reviews, you can visit the product page using the following link.

View Product on Amazon

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Final Verdict

The APUS 190,000 BTU tankless water heater offers a compelling package for homeowners seeking a propane-powered outdoor unit with smart features and solid performance specs. Its 8.1 GPM flow rate and precise temperature control make it a viable option for whole-home use in moderate climates. The inclusion of a Tuya-compatible app and wired remote adds convenience that many users appreciate.

On the downside, the shorter warranty (2 years compared to 5+ years from some rivals) and outdoor-only installation may limit its appeal for some buyers. Additionally, the relatively small number of customer reviews means long-term reliability is less proven. However, given the competitive pricing and robust feature set, this unit is worth strong consideration if it matches your home’s setup.

In short, the APUS 190000 BTU tankless water heater review shows it’s a capable, modern option that can meet the hot water demands of many households. We recommend it for those who are comfortable with outdoor installation and want a smart, efficient propane water heater without overspending.

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FAQ

Can the APUS 190,000 BTU water heater be installed indoors?

No, this specific model is designed for outdoor installation only. APUS does offer indoor models, but this unit requires outdoor mounting to ensure proper ventilation.

Does this water heater work with natural gas?

This model is factory-set for liquid propane. There is a separate natural gas version (likely with a different model number). Check the product listing carefully before purchasing.

How do I control the temperature through the app?

After installation, download the Tuya smart app, create an account, and pair the heater with your phone. The app allows you to adjust the temperature from 95°F to 149°F, set schedules, and monitor usage.

What happens during a power outage?

Since the unit requires 120V AC to operate the control board and ignition system, it will not function during a power outage. If you need hot water in emergencies, a battery backup or generator is required.

Is the WiFi necessary for basic operation?

No. You can use the included wired remote controller instead of the app. The heater will still operate normally without WiFi; the app simply adds convenience features.

How often should I descale the heat exchanger?

For most homes, descaling every 6 to 12 months is recommended. In areas with very hard water, more frequent flushing may be needed to prevent mineral buildup.

Does the heater come with a warranty?

Yes, APUS offers a 2-year full warranty on all components. You should register the product online after installation to activate the warranty.

Can this unit be used with a tank or booster?

It is designed as a standalone tankless unit. However, some installers may use it in conjunction with a storage tank for large commercial applications. For typical residential use, it works without a tank.

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