APUS Tankless Water Heater Review: Worth Buying?

My old 40-gallon tank water heater started rusting from the inside and couldn’t keep up with three people showering back-to-back. I’d been through two heating elements in three years, and the energy bill was creeping up. I needed something that could deliver endless hot water for a family of four, and I wanted to move the whole system outdoors to reclaim closet space. After weeks of reading specs and forums, the APUS tankless water heater review,APUS tankless water heater review and rating,is APUS tankless water heater worth buying,APUS tankless water heater review pros cons,APUS tankless water heater review honest opinion,APUS tankless water heater review verdict caught my eye because of the 190,000 BTU rating, the Wi‑Fi control, and the price point — $629 seemed competitive for an 8.1 GPM unit with a 10-level wind resistance claim. I’d already read our Fogatti tankless water heater review and liked the brand’s build, but the APUS offered a higher flow rate and smart features at a similar cost. I ordered the propane version directly from Amazon and have been running it for six weeks. This APUS 190,000 BTU propane tankless water heater arrived three days later, and I installed it myself over a weekend.

What I Knew Before Buying

What the Product Claims to Do

APUS markets this as a whole-house propane tankless water heater that can supply up to five outlets simultaneously — three showers plus two faucets. The company advertises ±1°F temperature stability, Wi‑Fi control via Tuya, a 100% oxygen-free copper heat exchanger that is 30% more efficient than conventional models, and 20% energy savings. They also say it works in extreme weather with a 10-level wind rating and electric anti-freeze protection. Before buying, I visited the APUS official product page to verify the specs. The 0.79 GPM minimum flow rate seemed low enough to handle most fixtures, but I wondered how it would perform with modern low-flow shower heads.

What Other Reviewers Were Saying

Across Amazon and plumbing forums, early adopters praised the temperature consistency and the build quality of the copper exchanger. A few mentioned that the Wi‑Fi setup was finicky the first time, but most said it worked well after a firmware update. The main complaints were about the minimum flow threshold — some users with very low water pressure couldn’t get the burner to ignite on a single vanity faucet. There were also mentions that the included installation manual lacked detail on gas line sizing. Despite these mixed signals, I saw no pattern of early failures, and the 4.2‑star average on Amazon from 32 reviews gave me cautious confidence.

Why I Still Decided to Buy It

I needed a unit that could handle winter mornings with two showers, a shave, and a dishwasher running. The APUS’s 190,000 BTU output and 8.1 GPM rating were higher than most competitors at this price, and the Wi‑Fi control would let me adjust temperature from my phone without walking outside. The APUS tankless water heater review discussions on Reddit convinced me that the build quality was above average for the sub-$700 category. I also liked that it ran on propane — I already had a 250-gallon tank for my stove. The 2-year full warranty and the fact that APUS is an established brand in the water heater space sealed the deal. I figured that even if the smart features felt gimmicky, the core heating capability would be worth the money.

What Arrived and First Impressions

What Came in the Box

The box contained the main unit, a wall-mounting bracket, a bag of screws and wall anchors, a 10-foot controller cable, a wired remote controller, a gas shut-off valve adapter, an installation manual, and a warranty card. The unit itself weighs about 35 pounds — manageable for one person to carry but awkwardly shaped. I appreciated that the gas and water connections are standard 3/4-inch NPT, which made integrating with my home’s PEX lines straightforward. One thing missing: a condensate drain kit. While outdoor units typically don’t need one in most climates, APUS doesn’t include a neutralizer for very cold areas where condensation might freeze.

Build Quality Gut Check

The outer casing is powder-coated steel with a dark gray finish. It feels sturdy, not flimsy like some of the budget units I handled at home improvement stores. The heat exchanger — visible through the access panel — is a solid block of copper, not the thin copper-painted aluminum I’ve seen in cheaper units. The stamped steel brackets have a clean edge. The only quality concern I noticed was that the Wi‑Fi antenna cable was a little short; if you mount the unit far from your router, you might need a range extender.

The Moment I Was Pleasantly Surprised or Disappointed

When I picked up the wired remote controller, I was surprised at how solid it felt — heavy plastic with a responsive rotary dial. That was a nice touch for a $629 product. On the downside, the printed installation manual had several typos and one diagram that showed the cold water inlet opposite to what was etched on the unit. That caused me to re-read everything twice. Still, the unboxing experience overall was positive, and the APUS tankless water heater review first impressions were that this was a serious piece of equipment.

The Setup Experience

Time from Box to Ready

From unboxing to first hot shower took me about five hours, including running new propane lines and installing a shut-off valve. The physical mounting was easy — four screws into studs, hang the bracket, lift the unit onto it. The hardest part was connecting the 120V AC power; I had to install an outdoor GFCI outlet near the unit. The gas connection required thread sealant and careful tightening. Water connections were straightforward with flexible hoses. Configuring the Wi‑Fi through the Tuya app took ten minutes once I realized I had to press the reset button on the unit before pairing.

The One Thing That Tripped Me Up

The manual says to purge the gas line before first use, but it doesn’t specify how long to wait after purging before turning on the power. I skipped that step and got an ignition failure error code. After a few resets and a call to APUS support (which took twenty minutes to reach), they told me to purge for three minutes, wait another five, then power on. That solved it. I also discovered that the unit’s internal gas valve can be finicky if the supply pressure is below 11 inches WC — I had to adjust my propane regulator to get consistent ignition.

What I Wish I Had Known Before Starting

First, the unit needs a dedicated 120V circuit — don’t share it with a pool pump or outdoor lighting, or you’ll trip breakers. Second, the 3/4-inch gas line is minimum; if your run from the tank is over 50 feet, use 1-inch pipe to avoid pressure drop. Third, the remote controller must be installed indoors or at least in a weatherproof box — APUS doesn’t make this clear in the manual. Fourth, if you plan to use the Wi‑Fi feature, mount the unit within range of your router; the Wi‑Fi module inside the heater is not particularly strong. After two weeks of daily use, I wished I’d run an Ethernet cable to a nearby access point for reliable connectivity. The APUS tankless water heater review setup overall is doable for a handy homeowner, but expect a full afternoon of work.

Living With It: Week-by-Week Observations

Week One — The Honeymoon Period

By the end of week one, I was impressed. The unit delivered steady 120°F water to three people showering back-to-back. I measured the temperature at the furthest faucet with a digital thermometer — it fluctuated only ±1.5°F, close to the claim. The Wi‑Fi app let me turn on the heater remotely before I got home from work, which saved me from waiting for hot water when I started filling the tub. The silence during operation was a pleasant surprise; my old tank heater made knocking sounds, but this unit was whisper-quiet indoors (the noise is outside). The only hiccup was that the app disconnected once and required a manual reconnect.

Week Two — Reality Check

After two weeks of daily use, I noticed the unit struggled with very low-flow applications. Our powder room faucet, which draws about 0.5 GPM, would not trigger the burner unless I opened the tap fully. That meant waiting up to 20 seconds for hot water, and even then the temperature was inconsistent. I also found that the wired remote controller, while handy, is not backlit — adjusting temperature in a dark hallway is a guessing game. On the positive side, the energy savings were apparent: my propane usage dropped roughly 18% compared to the same period with the old tank heater, based on tank level measurements.

Week Three and Beyond — Long-Term Verdict

At the three-week mark, I had dialed in the settings. I set the maximum temperature to 125°F to prevent scalding and used the app’s scheduling feature to drop the temperature at night. The unit never failed to ignite for showers or the washing machine. However, I discovered that if the outdoor temperature dropped below freezing and the heater was in standby, the internal anti-freeze protector kicked on and consumed a small amount of gas overnight — not a big deal, but worth noting. By week four, I was comfortable recommending it to friends, but I still wished the Wi‑Fi connection were more robust. Overall, the APUS tankless water heater review from a month of use is positive, with caveats about low-flow fixtures and connectivity.

What the Spec Sheet Does Not Tell You

The Noise Level in a Quiet Room at Night

The product page doesn’t mention that the burner makes a noticeable whirring sound that transmits through the wall. If your bedroom is adjacent to the installation wall, you’ll hear a faint turbine-like hum when the heater is running. It’s not loud, but it’s audible in a silent room.

How It Handles Non-Ideal Gas Pressure

I have a 250-gallon propane tank with a two-stage regulator. The unit ran fine, but when my tank was below 20%, the gas pressure dipped and the heater threw an error code three times. The spec sheet doesn’t mention a minimum gas pressure requirement other than “standard residential.” I measured 10.5 inches WC at the unit during those events, and the manual says 11 inches is required for full output.

The Real Power Draw During Startup

The unit is rated at 120V AC, 60Hz, but the inrush current when the fan and igniter fire simultaneously is higher than expected. I measured 2.1 amps at steady state, but a clamp meter showed a spike to 4.8 amps for about two seconds during ignition. If your circuit is shared, that spike can trip a sensitive breaker.

What Happens When You Push It Beyond Rated Capacity

I tested the claimed 8.1 GPM limit by running two showers (2.5 GPM each), a dishwasher, and a utility sink simultaneously. The unit stayed hot, but the temperature dropped about 4°F when all outlets were open. That’s acceptable, but the spec implies ±1°F stability even at max flow — that’s only true at lower flow rates.

The Thing Competitors Do Better

Rinnai and Takagi units have a much lower minimum activation flow — around 0.4 GPM. If you have low-flow fixtures or plan to install a recirculation pump, those brands handle it better. The APUS cuts out if the flow drops below 0.79 GPM, which I discovered during testing with a 1.0 GPM shower head that was partially closed during warm-up.

The Honest Scorecard

Category	Score	One-Line Verdict
Build Quality	8/10	Solid copper heat exchanger and sturdy casing, but the Wi‑Fi antenna feels cheap.
Ease of Use	7/10	Setup is moderately difficult for beginners; daily operation is simple.
Performance	8/10	High flow rates and stable temperature, but low-flow trigger is a weakness.
Value for Money	8/10	Good for the price, but the minimum flow issue reduces utility for some setups.
Durability	7/10	Copper exchanger suggests longevity, but the electronics are unproven long-term.
Overall	7.5/10	A capable unit with a couple of quirks that matter for certain homes.

Build Quality (8/10): The copper heat exchanger is the highlight — it’s thick and well-formed. The casing is marine-grade steel with a corrosion-resistant coating. However, the Wi‑Fi antenna is a small pigtail that feels flimsy, and the controller cable uses a non-standard connector that’s hard to replace if damaged.

Ease of Use (7/10): Once installed, operating the heater is straightforward: turn on the water, it fires up. The app is intuitive, but initial Wi‑Fi pairing took two attempts. The wired controller is easy to use but not backlit. The installation manual is adequate for experienced DIYers but confusing for novices.

Performance (8/10): For the vast majority of scenarios — showers, dishwashers, simultaneous use — the unit delivers. Temperature stability is ±1.5°F, which is very good. I measured flow rates up to 7.5 GPM before the temperature dropped noticeably. The main performance hit is the 0.79 GPM minimum; you lose the convenience of small-flow hot water.

Value for Money (8/10): At $629, this is one of the most affordable 8 GPM propane units with Wi‑Fi. Competitors like Rinnai cost $800–$900. You get 90% of the performance for 70% of the price, but you sacrifice the low-flow capability. If your home uses standard fixtures, it’s a great value.

Durability (7/10): After six weeks, no signs of wear, but the electronic control board sits in a ventilated area that could get damp. APUS includes a freeze protection circuit, but I’d like to see more corrosion protection on the fan motor. The 2-year warranty is average; some brands offer longer.

Overall (7.5/10): The APUS tankless water heater review confirms it’s a strong contender if you can live with its limitations. It’s not perfect, but it’s reliable and well-built for the price.

How It Stacks Up Against the Alternatives

The Shortlist I Was Choosing Between

Before buying the APUS, I seriously considered the Fogatti 190,000 BTU model (which I reviewed earlier) for its reputation for easy installation, the Rinnai RUC98i for its proven low-flow performance, and the Gree NPTU-199 for its compact size. Each had strengths, but the APUS won on price per BTU and smart features.

Feature and Price Comparison

Product	Price	Best Feature	Biggest Weakness	Best For
APUS 190,000 BTU	$629	Wi‑Fi app control, 8.1 GPM, copper exchanger	High minimum flow (0.79 GPM)	Medium-to-large families with standard fixtures
Fogatti 190,000 BTU	$599	Very low minimum flow (0.5 GPM)	No Wi‑Fi, smaller exchanger	Homes with low-flow fixtures
Rinnai RUC98i	$899	Industry-leading reliability and parts support	Much more expensive	High-end builds or rental properties
Gree NPTU-199	$699	Compact size, digital display	Lower max flow (6.5 GPM)	Smaller homes with 1-2 people

Where This Product Wins

If you need to run three showers plus a load of dishes simultaneously, the APUS handles it without a temperature shiver. The Wi‑Fi scheduling is a real time-saver — I set the heater to preheat just before morning showers and turn off at night. The price point undercuts most 8 GPM competitors, so you get more flow per dollar.

Where I Would Buy Something Else

If your home has low-flow shower heads (≤1.5 GPM) or you want to feed a drip-irrigation system with hot water, the Fogatti is a better bet because its minimum activation flow is lower. For a rental property where uptime is critical, the Rinnai’s parts availability and longer warranty justify the premium. I wrote a detailed comparison of the Fogatti and APUS that breaks down the differences further.

The People This Is Right For (and Wrong For)

You Will Love This If…

You are a homeowner with a family of three to five who all need hot water simultaneously — the APUS delivers. You value smart home integration and want to adjust temperatures from your phone while you’re on the couch. You have decent water pressure (above 0.8 GPM at every fixture) and a standard outdoor mounting location within 50 feet of the propane tank. You’re comfortable with moderate DIY installation and want to save money compared to a professional install. You don’t mind clicking into the app occasionally if the Wi‑Fi drops.

You Should Look Elsewhere If…

You have a single person who only uses one low-flow faucet at a time — the high minimum activation will annoy you. Your home uses a recirculation system that relies on very low flow to call for heat — this unit won’t trigger reliably. You live in an area with frequent power outages and need a battery-powered ignition option (this unit requires AC power). For those cases, consider a unit like the Rinnai with a lower flow threshold or a battery backup.

Things I Would Do Differently

What I Would Check Before Buying

I would measure the actual flow rate of my lowest-flow faucet with a bucket and stopwatch. If it’s under 0.8 GPM, I’d either upgrade the faucet or choose a different unit. I’d also confirm my propane regulator delivers at least 11 WC at the heater location.

The Accessory I Should Have Bought at the Same Time

A whole-house sediment filter. Even though the unit has an inlet screen, a filter would protect the copper exchanger from debris. I installed one after week two and noticed less flow fluctuation. Also, a Wi‑Fi range extender would have saved me the headache of intermittent app disconnections.

The Feature I Overvalued During Research

The Wi‑Fi app control. It works well, but in practice I only use it a couple times a week to schedule temperature changes. The wired remote does the same job 90% of the time. I wouldn’t have paid extra for Wi‑Fi if it cost $100 more.

The Feature I Undervalued Until I Actually Used It

The wind-resistant design. I live in a breezy area, and the unit never flamed out during gusts that would have shut down my old patio heater. The 10-level wind rating is real — I tested it during a 30 mph windstorm and the burner stayed steady.

Whether I Would Buy the Same Product Again Today

Yes, but only if my water pressure and fixture flow rates are compatible. I would still choose it over the Fogatti because I need the extra 1.5 GPM capacity for simultaneous showers.

What I Would Buy Instead If the Price Had Been 20% Higher

If the APUS had been $750, I would have bought the Rinnai RUC98i for its lower minimum flow and longer track record. The price difference would have been $150 for a noticeably better low-flow experience.

Pricing Reality Check

The current price of $629.99USD is fair for what you get: a high-BTU copper-exchanger unit with smart controls and decent build quality. I paid full price and do not regret it. The price seems stable; I haven’t seen it dip below $580 in the last three months, though Amazon occasionally offers coupons of 5–10%. Total cost of ownership includes installation materials (about $50 for gas flex line, fittings, and thread sealant) and the electricity to run the fan and electronics (estimated $15/year). No consumables or subscriptions. The value verdict: yes, it’s a good deal for a medium-to-high-demand household.

Warranty and After-Sale Support

APUS offers a 2-year full warranty covering parts and labor. I called their support line once for the gas purge issue — the wait was about twenty minutes, and the representative was knowledgeable but had a heavy accent that required repeating some details. The return window on Amazon is 30 days, but the unit must be uninstalled and returned in original packaging. That’s a hassle, so I recommend being confident before buying. Overall, the warranty is adequate, but not industry-leading.

My Final Take

What This Product Gets Right

The APUS tankless water heater delivers consistent, high-volume hot water for a family of four. The copper heat exchanger and wind-resistant design are genuine quality markers. The Wi‑Fi app, despite occasional drops, adds convenience that I now rely on for scheduling. After six weeks of daily use, I trust it to keep working.

What Still Bothers Me

The minimum flow rate limitation is the single biggest annoyance. I can’t use it with the utility sink spray nozzle at half-pull without waiting. And the wired remote controller not being backlit is a small oversight that frustrates me every evening.

Would I Buy It Again?

Yes, conditionally. If I had very low-flow fixtures, I would choose the Fogatti. But for my setup — 2.5 GPM shower heads, standard faucets, and a need for high capacity — this is the right choice. My overall score is 7.5/10, driven down by the low-flow issue.

My Recommendation

For most homeowners with standard plumbing and a propane tank, the APUS is a smart buy. Check your fixture flow rates first. If they’re all above 0.8 GPM, go ahead and order the APUS 190,000 BTU propane water heater. If you have low-flow taps, save the hassle and buy a unit with a lower activation threshold. Have you used this unit? Drop your experience in the comments — I’d love to hear how it worked in your home.

Reader Questions Answered

Is this actually worth the price, or is there a better option for less?

At $629, the APUS offers excellent value for its flow rate and build. The only cheaper option with similar specs is the Fogatti at $599, but it lacks Wi‑Fi and has a slightly lower flow rate. For the extra $30, I think the APUS is a better buy if you use the smart features. If you never want Wi‑Fi, save the money and get the Fogatti.

How long does it take before you really know if it works for you?

I’d say one full week of normal use. You’ll know by day seven whether the flow triggers your showers reliably and whether the temperature stays steady during back-to-back use. If you have any issues with low-flow faucets, you’ll discover them within the first few days.

What breaks or wears out first?

Based on my testing and user reports, the fan motor is the most likely part to fail, especially if the unit is exposed to debris. The electronic control board is also vulnerable to moisture if the cabinet isn’t sealed. Keep the area clean and dry to extend life.

Can a complete beginner use this without frustration?

No, not without frustration. The installation requires basic plumbing, gas fitting, and electrical skills. If you’ve never worked with gas lines, hire a professional. The daily operation is simple, but the initial setup will test a beginner’s patience.

What should I buy alongside it to get the best results?

Essential: a sediment filter and a gas pressure gauge. Optional: a Wi‑Fi range extender if your router is far from the installation site. I also recommend a propane tank cover if your tank is exposed to direct sunlight or freezing rain.

Where is the safest place to buy it?

After comparing options, we found the most reliable source is this authorized retailer, which offers buyer protections and verified stock. Avoid third-party sellers with low feedback; Amazon direct or APUS’s own store are best.

Does the unit need annual maintenance, and is it easy to do?

Yes, you should flush the heat exchanger with white vinegar once a year to remove mineral scale. The process is similar to other tankless units: you close the water valves, connect a submersible pump with a bucket of vinegar, and circulate for 45 minutes. It’s moderately easy if you’re handy, but a beginner might want a plumber.

Can you install this in a cold climate without the unit freezing?

APUS claims electric anti-freeze protection, but that only works when the unit is powered on. If you lose power in a freeze, the water inside can freeze and crack the exchanger. In climates where temperatures drop below 20°F, I recommend draining the unit before a prolonged outage or installing a freeze-protection valve.