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APUS Tankless Water Heater Review: Pros & Cons

If you are shopping for a propane-powered tankless water heater that can handle a busy household without taking up indoor space, the APUS 190,000 BTU outdoor model deserves a close look. This APUS tankless water heater review breaks down the unit’s features, performance expectations, and overall value so you can decide if it matches your hot water needs.

Whether you are replacing an aging storage tank or installing a new system, an on‑demand water heater can save energy and deliver endless hot water. The APUS unit promises whole‑home output, smart controls, and all‑weather durability. Below we examine every aspect—from BTU rating to installation requirements—to give you an honest, balanced assessment.

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

The APUS 190,000 BTU propane tankless water heater is an outdoor‑mounted, on‑demand water heating unit designed for whole‑house use. It belongs to the category of gas tankless water heaters, which heat water only when a tap is opened, eliminating the standby energy losses of traditional storage tanks.

Target users include homeowners with propane fuel access who need a high flow rate (8.1 GPM) to run multiple showers, faucets, and appliances simultaneously. The unit features Wi‑Fi and remote control capability, making it a smart‑home friendly option. It is suited for climates where an outdoor installation is practical, though its wind‑resistant and anti‑freeze features broaden its usability.

Key Features & Specifications

Below is a breakdown of the most important aspects of the APUS tankless water heater, based on the manufacturer’s data.

Feature	Detail
Power Source	Liquid Propane
Heat Output	190,000 BTU
Flow Rate	8.1 GPM
Maximum Temperature	149°F
Minimum Flow for Activation	0.79 GPM
Voltage	120 V AC
Dimensions (W × H × D)	6.54 × 22.48 × 15.51 inches
Mount Type	Wall‑mounted (outdoor)
Connections	3/4″ NPT water & gas
Smart Features	Tuya App control, wired remote
Heat Exchanger Material	100% oxygen‑free copper
Safety	Freeze/overheat/flame failure protection
Warranty	2‑year full warranty on components

Whole‑Home Hot Water: The manufacturer states this unit can supply three showers plus two faucets simultaneously, thanks to the 190,000 BTU burner and 8.1 GPM flow rate. The low minimum flow of 0.79 GPM helps the heater operate even in homes with weaker water pressure.
Smart Temperature Control: You can adjust the temperature between 95°F and 149°F via the Tuya smartphone app or the included wired controller. The manufacturer claims ±1°F accuracy, which is helpful for consistent comfort.
Compact Outdoor Design: With a depth of just 6.54 inches, the unit takes up minimal space on an exterior wall. It requires a standard 120 V outlet and uses 3/4″ connections, which are common in most U.S. homes.
Advanced Heat Exchanger: The 100% oxygen‑free copper heat exchanger is said to be 30% more efficient than conventional models, and the staged combustion technology reportedly delivers 20% energy savings compared to standard gas water heaters. Keep in mind these are manufacturer claims—actual savings depend on usage and water temperature.
All‑Weather Performance: The water heater is built to withstand wind up to level 10 on the Beaufort scale and includes electric anti‑freeze protection. This makes it suitable for outdoor installations in regions with strong winds or cold winters.
Complete Safety Protection: Multi‑layer safety systems cover freeze protection, overheat prevention, flame failure shutdown, and more. The 2‑year warranty backs the entire unit.

What’s Included in the Box

When you open the box, you will find the following components according to the manufacturer:

APUS tankless water heater (model AP‑AWH‑W26LPG)
Wired remote controller (optional, but included)
Controller cable (optional)
Two screws for the controller (optional)
Closed circuit terminal (optional, likely for hardwiring)
Installation and owner’s manual
Expansion screw
6 wall anchors and 4 mounting screws

Notably, the water heater comes with mounting hardware, but you will need to supply your own gas line, water piping, a shut‑off valve, a pressure relief valve (if required by local code), and a 120 V outlet. A typical outdoor installation also requires a gas regulator and a drip leg, depending on local codes. Always consult a licensed professional for installation.

How to Use

Setup and Installation

This is an outdoor‑rated unit, meaning it should be installed on an exterior wall with proper clearance for ventilation and service access. The manufacturer recommends mounting the heater at least 24 inches above the ground and away from windows, doors, or vents to prevent exhaust gas recirculation. Because the unit requires a 120 V electrical connection, you will need an outdoor GFCI‑protected outlet within reach.

Gas and water connections use standard 3/4″ NPT fittings. A licensed plumber or gas fitter should handle the gas line connection and any necessary pressure adjustments. The propane conversion (if needed) is typically set from the factory for propane—double‑check the model before installation. The unit requires a dedicated vent‑free installation because it is designed for outdoor use; never install it indoors or in an enclosed space.

Operation

Once installed, operating the APUS water heater is straightforward. Turn on the gas supply and plug in the power cord. Open a hot water tap anywhere in the house. The unit will automatically ignite the burner when it detects water flow above 0.79 GPM. The temperature can be adjusted using the wired remote or via the Tuya app (iOS and Android). The display shows the current temperature setting and any error codes if maintenance is needed.

For the smart features, download the Tuya app, create an account, and pair the water heater using the Wi‑Fi setup mode (consult the manual for specific steps). The app allows you to change temperature, set schedules, and monitor usage from your phone.

Maintenance

Routine maintenance is similar to other tankless water heaters. The manufacturer suggests periodically cleaning the inlet water filter (located at the cold water inlet) to prevent debris from affecting flow. In hard‑water areas, descaling the heat exchanger every 6 to 12 months is advisable to maintain efficiency—use a vinegar or citric acid solution and follow the manufacturer’s instructions. The exterior can be wiped with a damp cloth; avoid abrasive cleaners.

Troubleshooting

If the unit fails to ignite or shuts off unexpectedly, common causes include:

Insufficient gas supply (check the propane tank level and regulator)
Low water pressure below 0.79 GPM
Frozen condensate drain or blocked air intake in cold weather
Error code on the display (refer to the manual)

If problems persist, contact APUS customer support or a qualified technician. Do not attempt to disassemble the burner assembly yourself.

Performance & User Experience

Based on the manufacturer’s claims and general tankless water heater knowledge, the APUS 190,000 BTU model should deliver a substantial amount of hot water. The 8.1 GPM flow rate at a 35°F rise (typical for warmer climates) can support multiple fixtures. However, in colder regions where incoming groundwater is lower, the actual flow rate at a higher temperature rise will be less. For example, at a 50°F rise, the flow may drop to about 5.5‑6.0 GPM, which is still adequate for two showers running concurrently.

The Wi‑Fi control through the Tuya app is a convenient feature, allowing you to preheat the water or adjust temperature from anywhere. User reviews on Amazon (4.3 out of 5 stars from 42 ratings) generally praise the build quality and ease of installation, though some note that the remote controller cable could be longer. The low minimum flow rate is a genuine advantage for homes with low water pressure, as it prevents the heater from cycling on and off.

Potential downsides include the need for a dedicated 120 V outlet—some competing models are battery‑ignited or use a small hydro‑generator. The outdoor‑only restriction means it cannot be installed in an attic or basement. Additionally, the unit’s 2‑year warranty is shorter than some high‑end brands that offer 5‑year or longer coverage on the heat exchanger.

Overall, the APUS unit appears to be a solid mid‑range option for those who already heat with propane and want a smart‑ready, weather‑resistant unit. As with any tankless water heater, proper sizing and installation are critical for performance.

Pros and Cons

Pros

High 190,000 BTU output provides ample hot water for a large household
Low activation flow (0.79 GPM) works with weaker water pressure
Wi‑Fi app control and wired remote offer flexible temperature management
Compact outdoor design saves indoor space
Oxygen‑free copper heat exchanger claimed to be efficient and durable
Wind‑resistant and anti‑freeze features enhance reliability in harsh weather
Comprehensive safety protections included

Cons

Requires a nearby 120 V outlet (not battery‑powered)
Outdoor installation only—not suitable for indoor use
Warranty is 2 years, shorter than some competitors’ offerings
Smart app may need occasional Wi‑Fi reconnection
Limited user reviews (42 at time of writing) so long‑term reliability is less established

Comparison With Alternatives

To help you evaluate the APUS tankless water heater, here is how it compares to a couple of well‑known alternatives in the same category.

Rinnai V65iP (Outdoor Propane Tankless)

The Rinnai V65iP offers 180,000 BTU and 6.5 GPM, slightly lower capacity than the APUS. It also features Wi‑Fi compatibility (Rinnai Control‑R) and has a longer warranty (5 years for labor, 10 years for heat exchanger). Rinnai is a market leader with a strong reputation. However, the APUS edges ahead in flow rate and includes a wired remote in the box. If you need higher simultaneous usage, the APUS may be a better fit; if long‑term warranty is a priority, Rinnai might be preferable.

EcoSmart ECO 27

The EcoSmart ECO 27 is an electric tankless water heater with 27 kW (about 92,000 BTU equivalent) and delivers up to 6.5 GPM depending on water temperature. It is compact and requires no gas line, but it needs a heavy‑duty 240 V circuit. For propane availability, the APUS is a more powerful option. Electric tankless units generally have lower flow rates in cold climates, so the APUS propane model is better suited for whole‑house demand.

For a broader overview of tankless water heater types, you may find this Department of Energy resource helpful.

Who Should Buy This Product?

Ideal Users

Homeowners with an existing propane supply who want to eliminate a storage tank
Those who need to run 3+ fixtures simultaneously (e.g., large families)
People looking for an outdoor unit with smart controls and remote access
Homes with low water pressure that still demand reliable ignition
Anyone who prefers a compact, wall‑mounted solution to free up indoor space

Not Ideal For

Homes without access to a 120 V outlet near the installation site
Indoor installations (the unit is not certified for indoor use)
Users who require a very long warranty period (2 years may be shorter than desired)
Those on natural gas—this specific model is propane; check for a natural gas version
Very cold climates where inlet water is below 40°F frequently—flow rates will drop significantly

Expert Tips

Size for your climate. In cold northern states, a 190,000 BTU unit may still struggle to deliver 8.1 GPM at a 60°F+ rise. Use a tankless sizing calculator to confirm your needs.
Install a whole‑house sediment filter. Propane tankless heaters benefit from clean water to prevent scale buildup on the heat exchanger. A 5‑micron filter before the unit helps extend its life.
Enable the “low flow” setting. If you have low water pressure, ensure the heater’s minimum flow setting is activated (often through the remote) to avoid cold water sandwiches.
Position the user remote conveniently. The wired remote can be mounted inside the home near a frequently used faucet for quick temperature adjustments.
Perform a yearly flush. Even with soft water, descaling once a year with a pump and vinegar solution helps maintain efficiency—especially if you live in a hard‑water area.

Common Mistakes

Installing without a gas line drip leg. This is required by most codes to catch debris from the gas line. Skipping it can lead to burner issues.
Oversizing without checking flow rates. A 190,000 BTU heater is powerful, but if your home’s incoming water temperature is very low, actual simultaneous use may be less than expected.
Neglecting the electrical requirement. The heater needs a continuous 120 V supply—hardwiring is possible, but many users forget to run a dedicated circuit.
Mounting too close to windows or doors. Exhaust gases can re‑enter the home; maintain minimum clearances as specified in the manual.
Assuming the app works without stable Wi‑Fi. The Tuya app relies on a 2.4 GHz Wi‑Fi signal. Weak signal near the heater can cause connection drops.

Where to Buy

The APUS 190,000 BTU propane tankless water heater is widely available online. For the most reliable purchasing experience, consider major retailers like Amazon. Buying through an authorized seller ensures you receive a genuine unit with the full manufacturer warranty.

View Product on Amazon

If you are considering other options, you can also explore tankless water heaters from brands like Rinnai, Rheem, or EcoSmart, but verify the specifications match your fuel type and installation requirements.

Final Verdict

The APUS 190,000 BTU propane tankless water heater offers a compelling combination of high capacity, smart features, and weather‑resistant design. Its 8.1 GPM flow rate and low activation threshold make it a strong performer for whole‑house use, especially in homes with moderate to low water pressure. The Wi‑Fi and remote control add convenience that many competing units at this price point lack.

That said, the 2‑year warranty and relatively low number of user reviews mean some caution is warranted—especially for buyers accustomed to longer coverage from established brands. The outdoor‑only installation is a limitation, but it also frees up interior space and suits many modern home layouts.

Overall, if you need a powerful propane tankless water heater with smart controls and you are comfortable with the warranty term, the APUS unit is a worthwhile option. We recommend having it professionally installed and performing regular maintenance to maximize its lifespan.

Frequently Asked Questions (FAQ)

Can the APUS tankless water heater be used indoors?

No. This model is designed and certified for outdoor installation only. Installing it indoors or in an unventilated space could create dangerous exhaust gas buildup.

Does the heater require a electrical outlet?

Yes. It needs a standard 120 V AC outlet (15‑amp circuit) to power the control board, fan, and ignition system. It does not run on batteries alone.

What is the minimum water flow needed to activate the burner?

The manufacturer specifies a minimum flow of 0.79 GPM. Below that, the heater may not turn on or may cycle.

Can the temperature be adjusted precisely?

Yes. The temperature range is 95°F to 149°F, adjustable in 1°F increments via the wired remote or the Tuya app.

Is this water heater compatible with natural gas?

This specific model (AP‑AWH‑W26LPG) is factory set for liquid propane. APUS offers a separate natural gas version; check the product listing to confirm fuel type before purchasing.

How do I clean the water filter?

Turn off the water and disconnect the cold water inlet union. Remove the mesh filter and rinse it under running water. Reinstall and tighten. This should be done every few months or as needed.

What does the warranty cover?

APUS provides a 2‑year full warranty on all parts and components for the original purchaser. This does not include labor for repairs. Always register your product with the manufacturer after purchase.

Can the unit be installed in freezing temperatures?

Yes. The heater has built‑in electric anti‑freeze protection that activates when internal temperatures drop near freezing. However, the water lines feeding the unit must also be insulated or heat‑traced to prevent freezing.

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