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

The APUS 190000 BTU tankless water heater is a propane-powered, whole-home instant water heater designed for outdoor installation. It can supply up to 8.1 gallons per minute (GPM) of hot water on demand, making it suitable for households needing simultaneous service to multiple fixtures—manufacturer claims it can handle three showers and two faucets at once. This unit is part of the growing market of high-BTU tankless water heaters aimed at replacing traditional storage tank heaters for improved efficiency and endless hot water.

Target users include homeowners seeking to upgrade from a tank water heater, those with existing propane supply, or anyone looking for a compact outdoor solution that doesn’t take up floor space inside. It’s also a candidate for vacation homes or rental properties where reliability and space savings matter.

If you’re researching whether this APUS propane water heater is the right fit for your home, this detailed review will help you weigh its features, potential drawbacks, and overall value.

Key Features & Specifications

The APUS 190,000 BTU unit comes with several noteworthy specifications and technologies. Below is a summary of the most important details as provided by the manufacturer.

Feature	Specification
Power Source	Liquid Propane (also available in Natural Gas models)
Heat Output	190,000 BTU
Flow Rate	8.1 GPM
Minimum Flow to Activate	0.79 GPM (ultra-low startup)
Temperature Range	95°F – 149°F
Temperature Accuracy	±1°F
Heat Exchanger Material	100% oxygen-free copper (manufacturer claims 30% more efficient than conventional)
Control Options	WiFi via Tuya app + wired remote controller (included)
Dimensions (W x H x D)	22.48 × 15.51 × 6.54 inches
Voltage	120V AC (standard outlet)
Wind Resistance Rating	10-level (manufacturer claim)
Anti-Freeze Protection	Electric (active freeze protection)
Warranty	2-year full warranty on components

Smart Temperature Control & WiFi Connectivity

The APUS tankless water heater integrates with the Tuya smart home platform, allowing you to adjust the outlet temperature remotely via a smartphone app. The included wired remote controller also provides local control with a temperature range of 95°F to 149°F. The manufacturer states ±1°F stability, which is in line with many modern tankless water heaters. Smart seasonal technology automatically adjusts the burner to match incoming water temperature, which could improve efficiency during warmer months.

Advanced Heat Exchanger & Combustion

The heart of the unit is an oxygen-free copper heat exchanger, which the manufacturer says is 30% more efficient than conventional water heaters. Combined with intelligent staged combustion, the system is claimed to deliver 20% energy savings compared to standard gas water heaters. While these figures come from the manufacturer, oxygen-free copper is generally considered a premium material that resists corrosion and improves heat transfer.

All-Weather Design

Designed for outdoor installation, the APUS unit features wind-resistant construction (up to a 10-level wind rating) and electric anti-freeze protection. This means the heater can continue operating in windy and cold conditions without the water inside freezing, provided the unit is installed correctly and has power.

Safety Protections

The water heater includes freeze protection, overheat protection, and flame failure safeguards. These are standard safety features for propane tankless water heaters, but the comprehensive coverage adds peace of mind. The 2-year warranty covers all components, which is a reasonable period for this product category.

What’s Included in the Box

According to the product details, the APUS 190,000 BTU tankless water heater comes with the following components:

1 × Tankless water heater unit
1 × Wired controller (optional installation)
1 × Controller cable
2 × Screws for controller (optional)
2 × Closed circuit terminals
1 × Installation and owner’s manual
1 × Expandable screw
6 × Wall anchors
4 × Mounting screws

The unit itself is compact and ready for wall mounting. The wired controller can be installed in a convenient indoor location, allowing you to change temperature settings without going outside. The manual provides step-by-step guidance for installation, but note that most jurisdictions require a licensed professional to connect gas lines.

How to Use

Setup

Outdoor installation requires mounting the unit on a wall with adequate clearance for ventilation. Connect the 3/4-inch water lines (inlet and outlet) and the propane gas line (also 3/4-inch). The heater needs a standard 120V AC electrical outlet to power the control board, fan, and anti-freeze features. A gas pressure regulator may be required depending on your propane tank setup. Because gas and water connections must meet local codes, professional installation is strongly recommended.

Operation

Once installed and powered, turn on a hot water faucet. The flow sensor detects the demand (minimum 0.79 GPM) and ignites the burner. The water is heated instantly as it passes through the copper heat exchanger. You can adjust the output temperature using the wired controller or the Tuya app. The unit will modulate the gas flow to maintain the set temperature within ±1°F.

Maintenance

Regular maintenance includes periodic descaling to remove mineral buildup, especially in hard water areas. The manufacturer recommends flushing the heat exchanger with a descaling solution according to the manual. Also check the air intake and exhaust vents for debris or obstructions. The unit’s freeze protection is electric, so it must remain powered to function.

Troubleshooting

Common issues may include failure to ignite (check gas supply and igniter), temperature fluctuations (possible undersizing for simultaneous demand), or error codes displayed on the controller. The manual provides a comprehensive error code list. For persistent problems, contact APUS customer support under the 2-year warranty.

Performance & User Experience

Based on the manufacturer’s specifications and available user feedback (4.3 out of 5 stars from 42 ratings at the time of writing), the APUS 190,000 BTU tankless water heater generally meets expectations for a mid-range propane unit. The high BTU rating enables it to handle multiple simultaneous uses in moderate climates. However, performance depends heavily on incoming water temperature and flow rate. In very cold climates, the effective flow rate will drop because the unit must raise the water temperature more.

The ultra-low minimum flow of 0.79 GPM is a plus for homes with low water pressure or when using low-flow fixtures. Many tankless heaters require at least 0.5-1.0 GPM to activate, so this spec puts it on par with or better than many competitors.

The WiFi control via Tuya app is a convenient addition, allowing you to preheat water remotely or adjust temperatures from your phone. Some users report that the app setup is straightforward, though connectivity depends on your home WiFi signal strength near the unit.

One point to consider is the noise level. Tankless water heaters produce a distinct burner roar, which is normal but may be audible near windows. Outdoor installation helps mitigate this.

Pros and Cons

Pros

High flow rate (8.1 GPM) – suitable for large families or simultaneous use of multiple showers and faucets.
Compact outdoor design – saves indoor space and eliminates the need for venting through the roof.
Smart control options – WiFi app and wired remote provide flexible temperature management.
Low activation flow – works with low-flow fixtures or weak water pressure.
Oxygen-free copper heat exchanger – enhances heat transfer efficiency and longevity.
All-weather protections – wind-resistant and electric anti-freeze suitable for outdoor installations.
2-year warranty – reasonable coverage for a tankless water heater in this price bracket.

Cons

Requires professional installation – gas line and electrical connections must comply with local codes; not a DIY project for most.
Performance varies with climate – in very cold climates, the effective GPM will be lower due to the high temperature rise needed.
Noise during operation – typical for tankless units but may be noticeable outdoors.
Limited user reviews – only 42 ratings at this time, making long-term reliability data sparse.
Potential app connectivity issues – some users report occasional disconnections or setup hurdles.
Electric power needed – the unit will not operate during a power outage without a backup generator.

Comparison With Alternatives

When evaluating the APUS 190,000 BTU model, it helps to compare it with other popular tankless water heaters in similar capacity and price ranges. Below are two well-known alternatives. Note: pricing is not included per review guidelines.

Feature	APUS 190,000 BTU (Propane)	Rinnai RU199iN (Natural Gas/Propane)	EcoSmart ECO 27 (Electric)
BTU / Power	190,000 BTU	199,000 BTU	27 kW (approx 92,000 BTU equivalent)
Max Flow Rate	8.1 GPM	9.5 GPM (at 45°F rise)	5.3 GPM (at 45°F rise)
Fuel Type	Propane only (or Nat Gas model available)	Natural Gas or Propane convertible	Electric
Controls	WiFi + wired remote	WiFi (optional) + wired remote	Digital push-button (no WiFi on basic model)
Heat Exchanger	Oxygen-free copper	Primary copper + secondary stainless steel	Stainless steel
Warranty	2 years	12 years (heat exchanger) / 5 years parts	Lifetime (on heating elements), 1 year parts

The Rinnai RU199iN is a market leader with a longer track record and a more comprehensive warranty, but typically higher cost. The EcoSmart ECO 27 is an electric alternative that doesn’t require gas lines, but its flow rate is significantly lower and may not support whole‑home demand in large households. The APUS sits in a value-focused position, offering competitive specs and smart features at a likely lower price point.

Who Should Buy This Product?

Ideal Users

Homeowners with an existing propane supply or willing to install a propane tank.
Families needing continuous hot water for multiple bathrooms and kitchen.
Those looking for an outdoor installation to save interior space.
Buyers interested in smart home integration and remote temperature control.
People in moderate climates where incoming water temperature is above 50°F most of the year.

Not Ideal For

Homes in extremely cold northern regions where incoming water temperature dips below 40°F—the flow rate may drop below 5 GPM under high demand.
Those who cannot arrange professional gas line installation.
Users who prefer a longer manufacturer warranty (the 2-year coverage is shorter than some competitors).
Apartment dwellers or homes without outdoor space for mounting.

Expert Tips

Proper sizing is critical. Before purchasing, calculate your peak simultaneous hot water demand (shower flow + faucet flow). If two shower heads use 2.5 GPM each and a faucet uses 1 GPM, you need at least 6 GPM. Factor in your ground water temperature—the colder the water, the lower the effective GPM.
Install a whole-house sediment filter. Tankless water heaters are sensitive to debris and scale. A 20-micron filter on the incoming cold water line can protect the heat exchanger.
Consider a recirculation pump. If you have a large home, hot water at distant fixtures may take time to arrive. Adding a dedicated recirculation loop or a pump can improve comfort.
Test the WiFi range. Since the unit is outdoors, ensure your home’s WiFi signal reaches the installation location. A mesh network or range extender may be necessary.
Use the wired controller for daily adjustments. The app is convenient for away-from-home changes, but the wired controller is faster for regular temperature tweaks.

Common Mistakes to Avoid

Incorrect gas line size. Using a gas line that is too small can cause insufficient pressure and poor performance. Check the manual for minimum pipe diameter (likely 3/4 inch).
Ignoring venting requirements. Although outdoor units don’t need chimney vents, they still require adequate clearance from windows, doors, and mechanical intakes to prevent exhaust recirculation.
Skipping the pressure regulator. Propane systems often require a two-stage regulator. Without it, the water heater may not receive stable gas pressure.
Not flushing annually. Mineral buildup inside the heat exchanger reduces efficiency and can cause early failure. Follow the manufacturer’s descaling instructions.
Mounting too close to the ground. Snow accumulation can block airflow or damage the unit. Install it at least 12 inches above expected snow level.
Assuming the unit works during a power outage. Tankless heaters with electric ignitions and controls will not operate without electricity. Consider a backup generator if this is a concern.

Where to Buy

The APUS 190,000 BTU tankless water heater is available on Amazon. This channel often provides fast shipping, easy returns, and customer reviews that can help you make an informed decision.

View Product on Amazon

Final Verdict

The APUS 190000 BTU tankless water heater delivers a compelling package of high flow rate, smart controls, and outdoor convenience at a competitive price point. Its oxygen-free copper heat exchanger and all-weather protections suggest it can withstand the elements, while the Tuya app adds modern flexibility. However, potential buyers should be aware that the 2-year warranty is shorter than industry leaders, and actual performance depends heavily on ground water temperature and installation quality.

For homeowners with propane access who value space savings and want to upgrade from a tank heater, this model is worth serious consideration. It is less suited for extremely cold climates or those seeking the longest warranty coverage. If you’re looking for a APUS tankless water heater worth buying, this unit ticks many boxes, but we recommend comparing it side‑by‑side with a Rinnai or Rheem if warranty length is a priority.

For a balanced APUS 190000 BTU review pros cons, this article has covered the strengths and weaknesses honestly. We encourage you to check recent user reviews to see if any common long-term issues have emerged as the product gains more installations.

Frequently Asked Questions

Does the APUS 190,000 BTU water heater work with natural gas?

The model reviewed runs on liquid propane, but the manufacturer also offers a natural gas version (likely the same unit with a different orifice). Always verify the specific model number before purchasing.

What is the minimum flow rate needed to activate the heater?

The manufacturer states a minimum flow of 0.79 GPM. This is low enough to work with most low-flow showerheads and faucets.

Can I install this water heater myself?

While the unit mounts easily, gas line and propane connections must comply with local codes and are best handled by a licensed plumber or gas fitter. Improper installation can be dangerous and may void the warranty.

Does the WiFi control work without the wired controller?

Yes, the Tuya app can operate independently. The wired controller is included as an alternative for local use.

How often should I flush the heat exchanger?

Manufacturer recommends flushing at least once a year, or more frequently in areas with hard water.

Will this water heater work in freezing temperatures?

The unit features electric anti-freeze protection that activates when temperatures drop near freezing. However, it requires continuous power. If the power goes out, the protection is disabled, and water in the heat exchanger could freeze.

What is the noise level like?

Tankless water heaters produce a moderate burner roar, comparable to a furnace. Outdoor installation reduces interior noise, but you may hear it near the unit.

Does it come with a temperature pressure relief valve?

The product details do not mention a T&P valve. Check local codes; a T&P valve may be required on the hot water outlet line to prevent overpressure.

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