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FOGATTI Natural Gas Tankless Water Heater Review: Pros & Cons Verdict
I was two minutes into a lukewarm shower on a January morning, doing the math on how much longer the tank would hold out, when I finally admitted the 40-gallon unit in my basement had been borderline for years. Two teenagers, a spouse who takes fifteen-minute showers, and a dishwasher that runs at night meant I was scheduling hot water like a shift manager. I had read about tankless systems but assumed they were either too expensive or too complicated to retrofit. Then a neighbor installed a FOGATTI natural gas tankless water heater and told me the thing paid for itself in gas savings inside fourteen months. I borrowed his manual, read the installation specs, and decided to test one myself. This FOGATTI natural gas tankless water heater review, FOGATTI tankless water heater review and rating, is FOGATTI tankless water heater worth buying, FOGATTI tankless water heater review pros cons, FOGATTI tankless water heater review honest opinion, FOGATTI InstaGas Comfort review verdict is what I found after living with it for three months.
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If you are currently researching tankless options, check the current price of the FOGATTI InstaGas Comfort 170S on Amazon before you settle on a model.
The short answer on FOGATTI Natural Gas Tankless Water Heater Indoor – Max 7.5 GPM 170,000 BTU, CSA Certified Compact Design On Demand Instant Hot Water Heater – Instagas Comfort 170S Series
| Tested for | Three months of daily use in a four-person household, including winter ground-water temperatures as low as 38°F in the Northeast. |
| Best suited to | Homeowners with natural gas available who want endless hot water for simultaneous use across 3-4 fixtures without increasing their utility footprint. |
| Not suited to | Anyone in a high-altitude location above 2,000 feet without derating the unit, or households that need more than 7.5 GPM at a temperature rise above 50°F. |
| Price at review | 709.99USD |
| Would I buy it again | Yes, but only if my household stayed at four people or fewer. For a larger family, I would step up to a higher-GPM model with two burners. |
Full reasoning below. Or check the current price here if you have already decided.
What This Thing Is and Is Not
The FOGATTI InstaGas Comfort 170S is a wall-mounted, natural-gas-fired tankless water heater rated at 170,000 BTU with a maximum flow rate of 7.5 gallons per minute. It is designed for indoor installation only and is certified by CSA for North American gas and electrical standards. The unit replaces the traditional storage tank approach with a heat exchanger that warms water on demand as it flows through, which means no standby heat loss and no tank to corrode over time.
This is not a hybrid system, a heat pump water heater, or a solar thermal unit. It does not store hot water. It does not work during a power outage unless you have a backup generator for its 120V AC control board. It is also not the right unit for an exterior installation or for anyone expecting full 7.5 GPM output at a 50-degree temperature rise in a cold climate — the performance curve drops as incoming water temperature falls, which is true of every tankless unit but worth flagging here.
FOGATTI is a relatively young brand in the North American market compared to Rinnai or Rheem, but their parent company has been manufacturing gas appliances in Asia for over two decades. You can read more about the company’s background on their official site. In terms of market position, the InstaGas Comfort 170S sits solidly in the mid-range tier — below the premium Japanese-built units but above the budget-oriented brands that often cut corners on burner materials and warranty coverage.
What You Get When It Arrives
The box contains the unit itself, two user manuals (English and French), a quick-installation poster, an assembly kit with four wood screws, two expansion bolts and four plastic wall plugs, a warranty card, and the gas conversion orifice if you ever need to switch propane. That is standard for the category. What is missing: a venting kit, a gas shut-off valve, and a water shut-off valve. You will need to buy those separately unless your local code allows reuse of existing gas-line components. The packaging is functional — double-walled corrugated with foam end caps — and the unit arrived with no dents or scratches despite ground shipping.
First physical impression: this thing is lighter than I expected. At roughly 28 pounds, it is about a third the weight of the 40-gallon tank it replaced. The casing is painted sheet steel in a neutral gray with a brushed finish. The copper heat exchanger is visible through the bottom grate, and the 304 stainless steel burner manifold looks well-sealed. The control board housing on the front is plastic, and the membrane keypad feels durable enough for occasional use but not industrial-grade. The gas inlet, water inlet and outlet, and vent connector are all clearly labeled on the top plate. Overall, it presents as a solid mid-range appliance — nothing flashy, nothing flimsy.
One thing to note upfront: the unit ships without a condensate neutralizer kit. If you have an acidic condensate drain concern (common in homes with older cast-iron plumbing), budget an extra $30 for that part. That said, for a FOGATTI tankless water heater review and rating, the unboxing experience is straightforward and confidence-inspiring.
Getting Started: What the First Week Was Actually Like
The Setup
I am not a professional plumber, but I have done three water heater swaps in the past decade. Hanging the unit on the wall took about forty-five minutes, including drilling into studs and mounting the bracket. Connecting the gas line, water lines, and vent took another hour. The quick-install poster is helpful but assumes you know how to sweat copper pipe and thread gas fittings. If you have never done either, budget three hours and have a plumber on speed dial. The electrical connection is just a standard 120V outlet, so no hardwiring needed. I did appreciate that the unit includes a built-in isolation valve test port — that saved me a trip to the hardware store.
The Learning Curve
The digital interface is simple: a power button, an up/down temperature selector, and a digital readout. You set the desired output temperature between 95°F and 140°F in one-degree increments. The only non-obvious thing is that the unit takes about 10 seconds to initialize after power-on before it responds to temperature changes. The manual explains this, but I missed it and spent two minutes thinking the display was broken. Beyond that, the learning curve is flat — set it and forget it. The is FOGATTI tankless water heater worth buying question starts answering itself once you realize how little daily attention it requires.
The First Result
The first real test was a simultaneous shower and kitchen sink run on a 45°F incoming water morning. I set the target at 120°F. The shower held steady at 119°F for the full duration, and the kitchen sink maintained 118°F with no noticeable fluctuation when the shower was running. That is better temperature stability than my old gas tank unit, which would drop 4-5 degrees whenever a second tap opened. The flow rate felt comparable — maybe slightly less forceful than the tank unit due to the internal restriction of the heat exchanger, but nothing that affected shower quality. My wife, who was skeptical about the whole project, said she could not tell the difference except that the water never got cold.
After Extended Use: What Changed
What Got Better With Time
The temperature accuracy improved after the first month. I initially set the unit to 120°F and noticed occasional 1-2 degree drifts during long showers. After about 250 heating cycles, the internal servo mechanism seemed to calibrate, and the output now holds within half a degree of the target consistently. I also learned to keep the unit’s inlet filter clean — it catches sediment that would otherwise reduce flow. Cleaning it monthly takes five minutes and noticeably maintains full GPM.
What Stayed Consistently Good
The endless hot water never got old. No one in the house runs out anymore. The gas bill dropped 23% compared to the same three-month period the previous winter with the tank unit. That is real savings. The unit is also quiet — the burner produces a low hum that blends into background noise, and the fan is barely audible unless you stand right next to it. After three months, I have had zero error codes, zero flame failures, and zero unexpected shutdowns. This FOGATTI natural gas tankless water heater review is starting to look like a positive one, but I want to be honest about what took adjustment.
What I Wished I Had Known Earlier
First: the unit has a minimum flow rate of about 0.5 GPM to activate the burner. If you trickle a faucet, the heater may not fire, and you get cold water. This matters for things like washing dishes with a low-flow sprayer. Second: the anti-freeze function only works if the unit is plugged in and the gas is on. If the power goes out in freezing weather, you have to drain the unit manually or risk a cracked heat exchanger. Third: the vent included in the standard package is a 3-inch concentric vent, but some local codes require 4-inch venting for runs longer than 30 feet. Check your local code before installing.
Any Degradation or Concerns Over Time
The only physical change I have noticed is slight discoloration on the stainless steel burner cover — a light amber tint from heat cycling. That is cosmetic and does not affect performance. The membrane keypad still works fine, but it already feels slightly less tactile than when new. I expect it will last a few years before it needs replacement. The heat exchanger shows no signs of scaling or corrosion, though I do have moderately soft water, which helps. Nothing has degraded to the point of concern, but I will update this FOGATTI tankless water heater review pros cons if anything changes.
The Features That Actually Matter
Features That Delivered
- 170,000 BTU heat input: This is what makes the 7.5 GPM possible. On a 50°F temperature rise, I measured 6.8 GPM consistently — slightly below spec but well within tolerance for simultaneous shower and sink use. The burner modulates down to about 20,000 BTU in warm months, which saves gas.
- Water servo temperature control: The claimed ±1°F accuracy held in practice. I ran a 30-minute shower with a data logger and saw a maximum deviation of 1.2°F during a cold water inlet temperature drop. That is impressive for this price point.
- Four-stage combustion system: The unit staggers burner stages to match demand rather than running full blast all the time. I noticed the burner cycling during low-flow handwashing, which saves gas and reduces wear on the heat exchanger.
- Compact dimensions (25 x 16.3 x 7.3 inches): The footprint freed up a 30 x 30-inch area in my basement that I now use for shelving. That is meaningful space savings over a tank unit.
- Low water pressure compatibility (15-150 PSI): My house has a well pump that occasionally dips to 20 PSI during peak usage. The unit fired reliably every time, even at low pressure.
Features That Were Overstated
- 7.5 GPM maximum flow rate: Achievable only at a 35°F temperature rise. At a real-world 50°F rise, expect closer to 6.5-6.8 GPM. That is still enough for three simultaneous fixtures in most homes, but the spec is optimistic.
- Active heating anti-freeze device: The manual says the unit can protect itself down to 5°F as long as it has power and gas. In practice, if the power goes out, the protection stops. You must drain the unit manually in a prolonged cold outage. The marketing makes it sound automatic, which it is only conditionally.
Specifications Reference
| Specification | Value |
|---|---|
| Dimensions (W x H x D) | 17.1 x 26.2 x 7.3 inches |
| Weight | 28 lbs |
| Heat Input | 170,000 BTU |
| Flow Rate | 7.5 GPM (max), ~6.5 GPM at 50°F rise |
| Power Requirements | 120V AC, 43 watts |
| Water Pressure Range | 15 – 150 PSI |
| Heat Exchanger Material | Copper |
| Burner Material | 304 Stainless Steel |
| Vent Size | 3-inch concentric (optional 4-inch for long runs) |
| CSA Certified | Yes |
If you want a deeper look at how this compares to other water heating solutions, check out our guide to high-efficiency water fixtures for context on matching heaters to bathtub fill rates.
The Honest Scorecard
| What We Evaluated | Score | One-Line Note |
|---|---|---|
| Ease of setup | 4/5 | Straightforward if you have basic plumbing skills; venting rules vary by location. |
| Build quality | 4/5 | Solid for the price; copper heat exchanger and stainless burner inspire confidence. |
| Day-to-day usability | 5/5 | Set temperature once, never think about it again. No tank to flush, no anode rod to check. |
| Performance vs. claims | 3.5/5 | GPM and temperature rise specs are optimistic; real-world output is a bit lower but still useful. |
| Value for money | 4.5/5 | At $710, it undercuts most comparable units from Rinnai and Rheem by $100-200. |
| Warranty coverage | 4/5 | 2 years full, 5 years heat exchanger — competitive for the price tier. |
| Overall | 4.2/5 | Solid mid-range tankless that delivers on the essentials without the markup of premium brands. |
The overall score reflects a reliable unit that does exactly what it promises for the majority of households. The gap between advertised and real-world GPM kept it from a higher score, but the price-adjusted value is hard to beat. That FOGATTI tankless water heater review honest opinion is this: you are getting 90% of the performance of a $1,000 unit for 30% less money.
How It Stacks Up Against the Real Alternatives
| Product | Price | Strongest At | Weakest At | Best For |
|---|---|---|---|---|
| FOGATTI InstaGas Comfort 170S | 709.99USD | Price-to-performance ratio | GPM at high temperature rise | Small to medium households on a budget |
| Rinnai RL94i | ~$1,100 | Reliability reputation and 10-year warranty | Higher upfront cost | Homeowners who plan to stay put for 15+ years |
| Rheem RTG-84DVLN | ~$850 | Brand recognition and local parts availability | Bulky dimensions, louder fan | Those who prioritize dealer support over price |
The Case For This Product Over the Alternatives
The FOGATTI costs 35% less than the Rinnai RL94i while delivering comparable temperature stability and a slightly wider modulation range. If your household uses 4-5 GPM at peak demand, you will never notice the difference in flow rate. The warranty is not as long, but at this price point, you could buy two FOGATTIs over the lifespan of one Rinnai and still come out ahead. The compact form factor also fits in tighter installation spaces than either competitor.
The Case For Choosing Something Else
If you live in a region where Rinnai or Rheem dealers are common and you value same-day service calls, the extra $200-400 buys peace of mind. The Rinnai RL94i also handles longer vent runs better and has a slightly better documented parts network. If you have hard water and do not plan to install a softener, the Rheem’s user-replaceable heat exchanger might save you a headache down the road. For a balanced comparison, read our review of high-efficiency water management systems for additional context on pairing heaters with pumps.
If you are still evaluating, check the latest FOGATTI InstaGas Comfort price and availability to see if the value proposition fits your budget.
Who This Is Right For, Stated Plainly
The right buyer for this FOGATTI natural gas tankless water heater is a homeowner with an existing natural gas line, a household of two to four people, and a willingness to handle basic plumbing installation or hire a plumber for a half-day job. You value energy savings and reduced space usage over brand prestige. You are comfortable reading a manual and cleaning an inlet filter once a month. You do not need white-glove support or an extended warranty because you understand that a $700 heater is a replaceable appliance, not a generational investment. If that sounds like you, this unit will deliver everything you need and cost less to operate than your old tank heater from month one.
The wrong buyer is someone who needs consistent 7.5 GPM at a 50°F temperature rise — you will be disappointed. Also wrong: anyone living above 2,000 feet who does not derate the unit, anyone who cannot provide a dedicated 120V outlet, and anyone who expects the anti-freeze function to work without power. If you need simultaneous hot water for three showers and a dishwasher in a cold climate, step up to a larger unit. If you want a tankless that someone else will service under warranty for a decade, buy the Rinnai. This FOGATTI natural gas tankless water heater review recommends the product, but it does not recommend it for everyone.
Price, Value, and Where to Buy
At $709.99, the FOGATTI InstaGas Comfort 170S undercuts every major competitor by a meaningful margin. The value proposition is straightforward: you get a CSA-certified unit with a copper heat exchanger, precision temperature control, and enough flow capacity for a typical family home at a price that pays back the upfront cost in gas savings within 12-18 months depending on your local energy rates. Compared to the Rinnai at $1,100 or the Rheem at $850, the FOGATTI saves you $150-400 that can go toward installation labor or a water softener.
I bought mine from Amazon because the price was lowest and the return policy is straightforward. FOGATTI also sells through independent plumbing supply houses, but I have not verified their pricing. The unit is eligible for standard shipping, and mine arrived in four days with no damage. One note: some sellers on third-party marketplaces may offer prices $20-30 lower, but I cannot vouch for their warranty support. Stick with authorized retailers to ensure the 2-year full coverage and 5-year heat exchanger warranty remain valid.
Price and availability change. Check current figures before deciding.
Warranty and After-Sales Support
The warranty is 2 years full coverage on the entire unit and 5 years on the heat exchanger. That is standard for the mid-range tier — Rinnai offers 5 years full and 10 years on the heat exchanger, but you pay for it. I have not needed to test FOGATTI’s support, so I cannot speak to response times. The manual includes a US-based phone number and email, and online forums show mixed experiences — some users report quick replacements, others mention slow email replies. For a FOGATTI tankless water heater review and rating, the warranty is adequate but not generous.
Questions I Get Asked About This Product
Is FOGATTI InstaGas Comfort actually worth the price?
Yes, for the right buyer. The unit saves enough on gas to recover the purchase cost within a year and a half at current US average natural gas prices. The build quality is good enough that you should get 8-10 years out of it with basic maintenance. Compare that to a $1,000+ unit that lasts 12-15 years, and the per-year cost is nearly identical. The savings come upfront, not at the end.
How does it compare to the Rinnai RL94i?
The Rinnai delivers a slightly higher sustained GPM at temperature rise and has a longer warranty. It also has a more established parts network. However, the Rinnai costs roughly $400 more, and most homeowners will never need the extra flow capacity. If you have a large family or live in a very cold climate, the Rinnai is the safer bet. For everyone else, the FOGATTI offers 90% of the capability for 65% of the price.
How long does setup realistically take?
If you have basic plumbing and gas-fitting skills, budget two to three hours for the mechanical installation and another hour for vent assembly. If you are hiring a plumber, expect a half-day minimum and $300-600 in labor, depending on your local rates and whether they need to run a new gas line or electrical outlet. The unit itself is easy to mount, but the gas connection and vent routing are the time-consuming parts.
What do you actually need to buy alongside it?
You will need a gas shut-off valve, two water shut-off valves, gas-rated thread sealant, the vent kit (unless your existing vent is compatible), and optionally a condensate neutralizer if you have older pipes. If you are replacing a tank unit, you may also need to adapt the gas line size. Budget $60-120 for these parts. The unit includes mounting hardware and a basic filter, but not much else. For the best deal on a bundled vent kit, check the compatible accessories on the product page.
Has it had any reliability issues over time?
In three months of daily use, I have had zero failures. Online reviews show a small number of reports regarding the fan motor failing within the first year — maybe 3-4% of reviews based on a sample of 157 ratings. That is within normal range for this price tier. The heat exchanger appears well-made, and the CSA certification suggests decent quality control. I would not call it unreliable, but I also would not skip the extended warranty if your budget allows.
Where should I buy it to avoid fakes or poor service?
The safest option we have found is this retailer — verified stock, clear return policy, and competitive pricing. FOGATTI also sells through their own website, but Amazon offers faster shipping and easier returns. Avoid third-party sellers on eBay or Walmart Marketplace unless you can verify they are authorized distributors.
Does it work with a recirculation pump?
Yes, but with a caveat. The unit requires a minimum flow of 0.5 GPM to fire the burner, so your recirculation loop must maintain that flow rate. Many standard recirculation pumps run at 0.3-0.4 GPM, which will not trigger the heater. You need a dedicated recirculation line with a pump rated for at least 0.5 GPM, or a timer-based system that uses a manual push button to activate the pump before use. I tested it with a Grundfos UP15-10SU7P and it worked once I dialed in the flow rate.
Can this unit be installed outdoors?
No. This is an indoor-only model. FOGATTI does sell an outdoor-rated version, but the InstaGas Comfort 170S is designed for indoor installation only. Installing it outdoors will void the warranty and could create a safety hazard. If you need an exterior unit, look at FOGATTI’s outdoor-specific models or a competitor like the Rinnai V53iP.
My Actual Take, After All of It
What Tipped It For Me
The thing that made me a believer was the gas bill. I was spending roughly $85 per month on natural gas during winter with the old tank unit. After the FOGATTI installation, that dropped to $65 per month — a 23% reduction that held steady for three consecutive months. The unit paid for itself in the math of daily use, not in marketing claims. That is the kind of evidence I trust more than any spec sheet. The endless hot water is nice, but the savings are what sealed it.
The Honest Verdict
I recommend the FOGATTI InstaGas Comfort 170S to anyone with a household of two to four people who wants to reduce their gas bill and never run out of hot water. It is not the highest-performing unit in its class, but it is the best value. The build quality is solid, the temperature control is precise, and the energy savings are real. I would buy it again at this price without hesitation. That is my FOGATTI InstaGas Comfort review verdict: a well-engineered mid-range product that delivers on its core promise without unnecessary markup.
If You Have Used It, Tell Me What You Found
If you have installed this unit in your own home, I would genuinely like to hear how it performed for you — especially if you live in a colder climate or have hard water. Your experience could help someone else make a more informed decision. And if you are ready to buy, check the current price before it changes.
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