APUS 190000 BTU Tankless Water Heater Review: Honest Verdict

Introduction

For homeowners tired of running out of hot water mid-shower or paying to heat a bulky tank all day, a tankless water heater can be a game-changer. The APUS 190,000 BTU Outdoor Tankless Water Heater promises whole-home on-demand hot water with smart controls and rugged outdoor durability. In this APUS 190000 BTU tankless water heater review, we’ll break down the specs, features, and real-world considerations to help you decide if this propane unit fits your home. Whether you’re replacing an old tank or building a new system, our honest verdict will give you the clarity you need.

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

The APUS 190,000 BTU tankless water heater is a propane-powered, outdoor-mounted unit designed to supply hot water on demand for an entire household. With a flow rate of 8.1 gallons per minute (GPM) and a heat output of 190,000 BTUs, it is engineered to handle multiple simultaneous showers and faucets. The unit includes WiFi and remote control for temperature adjustments and is built to withstand outdoor elements. It caters to homeowners who want to eliminate the standby energy losses of traditional tank heaters and want a compact, space-saving solution.

Key Features & Specifications

Feature	Specification
Power Source	Liquid Propane
BTU Rating	190,000 BTU
Flow Rate	8.1 GPM
Maximum Temperature	149°F
Voltage	120V AC
Mount Type	Wall-mounted (outdoor)
Smart Home Compatibility	Yes (Works with Tuya App)
Dimensions (W x H x D)	22.48 × 15.51 × 6.54 inches
Minimum Flow Rate	0.79 GPM
Temperature Accuracy	±1°F
Heat Exchanger Material	100% oxygen-free copper

The manufacturer claims the advanced heat exchanger is 30% more efficient than conventional models and offers 20% energy savings thanks to intelligent staged combustion. The unit also features wind-resistant construction (10-level wind rating) and electric anti-freeze protection for all-weather use. Safety protections include freeze, overheat, and flame failure safeguards.

What’s Included in the Box

According to the product details, the APUS tankless water heater comes with the following items:

• Tankless water heater unit
• Wired controller (optional) with cable
• Screws (optional) and closed-circuit terminals (optional)
• Installation and owner’s manual
• Expandable screw, wall anchors (6), mounting screws (4)

Note that the wired controller and cable are listed as “optional” – they are included in the package but not required for operation since the unit also supports the Tuya smart app. The box contains the essentials for wall mounting, but you will need to supply the propane line, 120V electrical outlet, and water connections (standard 3/4-inch NPT).

How to Use

Setup

This unit is designed for outdoor installation only (do not install indoors or in enclosed spaces). Mount it on a sturdy wall using the provided brackets and hardware. Connect the propane gas line and water lines using standard 3/4-inch connections. Plug the unit into a 120V AC grounded outlet. The manufacturer recommends professional installation by a licensed plumber or gas fitter to ensure safe operation and compliance with local codes.

Operation

Once installed, the water heater activates automatically when a hot water tap is opened. You can set the desired temperature using either the wired controller (included) or the Tuya smart app on your smartphone. The app allows remote adjustments and monitoring. The unit maintains a steady ±1°F temperature accuracy. During cold weather, the anti-freeze system engages automatically when temperatures drop near freezing.

Maintenance

Periodic maintenance is recommended to keep the unit operating efficiently. The manufacturer suggests:

• Flushing the heat exchanger with vinegar or a descaling solution every 6–12 months to remove mineral buildup (especially in areas with hard water).
• Inspecting the air intake and exhaust for debris or blockages.
• Checking gas and water connections for leaks annually.
• Cleaning the water inlet filter regularly.

Troubleshooting

If the unit does not ignite, check that the propane supply is open and the gas line is properly purged of air. Error codes are displayed on the control panel; refer to the manual for specific codes. Common issues include low water pressure (unit requires a minimum of 0.79 GPM) or incorrect gas pressure. For persistent problems, contact APUS customer support.

Performance & User Experience

Based on the specifications provided by the manufacturer, the APUS 190,000 BTU tankless water heater is designed to deliver up to 8.1 GPM at a given temperature rise. For a typical household, this flow rate can handle three showers and two faucets simultaneously if the incoming water temperature is not extremely cold. In colder climates where groundwater temperatures drop, the actual GPM may be lower. The minimum flow rate of 0.79 GPM means it can operate even with weak water pressure, which is helpful for older homes.

The inclusion of WiFi control via the Tuya app is a modern convenience, allowing users to adjust temperature settings from anywhere, set schedules, or monitor energy usage. The wired controller provides a local backup option. The ±1°F accuracy is a claimed feature that should provide consistent water temperature, though actual performance can vary with gas pressure fluctuations and simultaneous demand.

User reviews (4.3 out of 5 stars from 42 ratings as of writing) generally praise the unit’s build quality and hot water output, though some note that installation can be challenging without professional help. A few users mention that the app connectivity can be finicky at times. As with any outdoor tankless unit, performance may degrade in extreme cold or high wind conditions despite the 10-level wind rating.

Pros and Cons

Pros

• High flow rate (8.1 GPM) suitable for whole-home use
• Smart control via app and remote – convenient temperature adjustment
• Compact, outdoor design saves indoor space
• Efficient heat exchanger with energy-saving staged combustion
• Low minimum flow rate works with low water pressure
• Robust safety features and 2-year warranty

Cons

• Propane only; natural gas conversion may require extra parts (not specified)
• Outdoor installation only – not suitable for indoor mounting
• Requires 120V electrical outlet – not completely self-powered
• Smart app reliability can vary based on user reports
• Professional installation recommended adds upfront cost
• Limited number of customer reviews available (42 at time of writing)

Comparison With Alternatives

To help put the APUS 190,000 BTU model in context, here are three popular alternatives in the same category:

Feature	APUS 190K BTU	Rheem RTEX-13	EcoSmart ECO 27	Stiebel Eltron Tempra 36
Power Source	Propane	Electric	Electric	Electric
BTU / kW	190,000 BTU	13 kW	27 kW	36 kW
Flow Rate (GPM)	8.1	3.9	5.6	7.5
Smart Controls	App + wired remote	None	None	None
Installation	Outdoor only	Indoor	Indoor	Indoor
Heat Exchanger	Oxygen-free copper	Copper	Copper	Copper
Warranty	2 years	Limited lifetime	Limited lifetime	5 years

The APUS unit stands out for its propane fuel, high flow rate, and smart control features – making it a good choice for households that already use propane or want the efficiency of gas without needing a larger electric service. Electric models like the EcoSmart ECO 27 or Stiebel Eltron Tempra 36 are simpler to install in indoor spaces but may require significant electrical upgrades. The Rheem RTEX-13 is more suited for point-of-use applications rather than whole-home.

Who Should Buy This Product?

Ideal users:

• Homeowners with an existing propane supply who want to replace a storage tank water heater.
• Those building a new home where outdoor gas line installation is straightforward.
• People who want smart home integration – the Tuya app works with Alexa and Google Assistant (though not explicitly stated, it’s common for Tuya-compatible devices).
• Households with moderate to high hot water demand (up to 3 bathrooms) in warmer climates where incoming water temperature is not extremely low.

Not ideal for:

• Homes without a suitable outdoor mounting location protected from direct weather or with insufficient wind shelter.
• Those who prefer a no-electricity setup – the unit requires 120V AC power.
• Users with very cold groundwater (e.g., northern winters) – flow rate at 8.1 GPM may drop significantly at high temperature rises.
• Customers who want a longer warranty or have had negative experiences with app-based controls.

Expert Tips

• Before purchasing, measure the temperature rise needed: subtract incoming water temperature from your desired hot water temperature. Then use the flow rate table (found in the manual) to estimate actual GPM. For example, a 70°F rise may reduce flow to around 5 GPM.
• Install a water softener or inline sediment filter if you have hard water. Mineral buildup can reduce the lifespan of the heat exchanger.
• Use a gas pressure gauge to ensure the propane supply delivers adequate pressure (typically 11” WC for residential propane). Low pressure is a common cause of poor performance.
• Program a weekly descaling reminder – tankless heaters need more maintenance than tanks.
• Position the unit away from obstructions that could block airflow, keeping at least 2 feet of clearance on all sides.

Common Mistakes

1. Undersizing the gas line – Propane tankless heaters need a large gas supply. Using a line that is too small can cause the heater to struggle or shut off. Always consult a professional.
2. Ignoring the minimum flow rate – The unit won’t fire if flow is below 0.79 GPM. This can be problematic with low-flow showerheads or faucets. Test your existing flow.
3. Skipping the anti-freeze preparation – Even with electric anti-freeze protection, if the unit is exposed to prolonged subfreezing temperatures without power, water can freeze and damage the heat exchanger.
4. Mounting in a poorly ventilated area – Outdoor installation still requires that the unit is not enclosed or tightly boxed in. Combustion air must be available.
5. Not flushing the system before first use – Debris from new plumbing lines can clog the internal filter. Flush with water before connecting gas.

Where to Buy

The APUS 190,000 BTU tankless water heater is available on Amazon through the official listing. Click the button below to view current stock and details.

Final Verdict

After reviewing the specifications, features, and user feedback, the APUS 190,000 BTU tankless water heater appears to be a solid option for households that want a propane-powered, whole-home unit with smart controls. Its 8.1 GPM flow rate and low minimum activation make it versatile for various water pressure situations. The outdoor design frees up indoor space but does require proper site preparation.

We rate it as a good value for those who already have propane and want to upgrade to tankless technology, especially if they value the convenience of app control. However, for users in very cold climates or those seeking a simpler, no-electricity solution, alternatives like a well-insulated tank heater or an electric tankless unit might be more appropriate. The 2-year warranty is shorter than some competitors, so budget for potential out-of-warranty repairs. If you’re comfortable with professional installation and periodic maintenance, the APUS unit is worth considering.

Frequently Asked Questions (FAQ)

Does the APUS water heater work with natural gas?

The unit listed is designed for liquid propane. The product description mentions natural gas variants (e.g., 190,000 BTU Natural Gas Heater), but the specific model sold on Amazon as of this writing is propane only. Check the product page for alternate versions if you need natural gas.

Can this water heater be installed indoors?

No. The manufacturer specifies outdoor installation only. It is not certified for indoor use due to combustion venting requirements.

What size propane tank do I need?

For whole-home use, a standard 120-gallon or larger propane tank is typically sufficient. The heater’s consumption is about 190,000 BTU per hour max. A 500-gallon tank is common for extended use. Consult a propane professional for sizing.

Does the WiFi app require a subscription?

According to the product details, the Tuya app is free to download and use. No subscription fees have been mentioned. You will need a 2.4 GHz WiFi network (most smart home devices require this).

What is the expected lifespan of this unit?

With proper maintenance, tankless water heaters typically last 15–20 years. The APUS unit’s oxygen-free copper heat exchanger should resist corrosion, but lifespan depends on water quality and usage patterns.

How does the anti-freeze protection work?

The unit has an electric heating element that activates when internal temperatures approach freezing, as long as power is supplied. It does not rely on draining the unit. In severe conditions, additional insulation or enclosure may be needed.

Does it come with a mounting bracket?

The included accessories list mounting screws and wall anchors, but a separate mounting bracket is not listed. The unit appears to have mounting points on the back; follow the manual for direct wall attachment.

Can I use this water heater with a recirculation pump?

Most tankless heaters can work with a recirculation system, but the manufacturer should confirm compatibility. The minimum flow rate may prevent the pump from triggering the heater. A dedicated recirculation loop with a timer is often recommended.

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