The Best Tankless Water Heaters for the Home – Picks from Bob Vila

Hot water, minus the hulking tank. If you’re upgrading to an on-demand (aka tankless) water heater, you’ve probably seen the “Picks from Bob Vila” lists that homeowners swear by. Below, I synthesize those favorites with testing insights and buyer-guide data to help you choose fasterand shower longer. We’ll translate specs like GPM, BTU, and UEF into plain English, compare gas vs. electric, lay out true-to-life costs, and highlight models that keep families happy (and arguments about “who used all the hot water” to a minimum).

Top Picks at a Glance

• Best Overall: Rinnai RU180iN (high output, rock-solid reliability, great whole-home hot water)
• Best Bang for the Buck (Point-of-Use/Electric): Rheem RTEX-13 (budget-friendly for sinks/showers in smaller homes)
• Best Electric Whole-Home: Stiebel Eltron Tempra 36 Plus (auto-modulation, whisper-quiet, excellent temp stability)
• Best Whole-House (Non-Condensing Gas): Rinnai RE199iN (9.8 GPM class, strong all-around performer)
• Best Condensing Gas: Takagi High-Efficiency 199k BTU class (10 GPM class, condensing efficiency with serious flow)
• Best Mid-Size Gas: Rinnai RL75iN (solid 2-bath capacity in moderate climates)
• Editor’s Alternate (Condensing + Built-In Recirc): Navien NPE-240A2 (top-tier efficiency; smart recirculation options reduce “cold sandwich” waits)

How to Choose a Tankless Heater (Without Getting Lost in Acronyms)

1) Start with flow rate and temperature rise

Your hot-water demand is measured in GPM (gallons per minute). Add up simultaneous usese.g., one shower (2.0–2.5 GPM) + dishwasher (1.0–1.5) + sink (0.5) and you’re at ~3.5–4.5 GPM. Next, calculate “temperature rise”: desired outlet temp (say 120°F) minus your incoming water temp (varies by region). Colder climates need more BTUs for the same GPM; warmer climates can get away with lower BTUs or smaller electric units.

2) Gas vs. Electric

• Gas (natural gas/propane): Higher single-unit flow, better for big households, but needs proper venting (non-condensing uses metal; condensing often uses PVC) and adequate gas supply.
• Electric: Simple to install, ultra-efficient at point of use, and great where venting/gas isn’t practical. Whole-home models may require panel upgrades (e.g., 150–200A service) and multiple breakers.

3) Condensing vs. Non-Condensing (Gas)

Condensing units reuse heat from exhaust, improving efficiency (and often letting you vent with PVC). They cost more up front but cut operating costs and exhaust temps. Non-condensing units are cheaper initially and still deliver strong flow, but exhaust is hotter and venting may cost more.

4) Uniform Energy Factor (UEF) & Incentives

UEF is the standardized efficiency score. For certain federal incentives, look for high-UEF models (especially for gas condensing tankless). Your utility may also offer rebates; always check your ZIP code.

5) Recirculation & Wait Times

If your bathrooms are far from the heater, a model with built-in recirculation (or a compatible pump loop) can slash “tap-to-hot” delaysgreat for kids, guests, and your sanity.

6) Installation Reality Check

Swapping from tank to tankless can involve gas-line upsizing, vent changes, condensate drains (for condensing), and electrical updates (for electric). Budget for professional labor plus permits where required.

Bob Vila–Inspired Picks, Explained

Sizing Cheat Sheet (Real-World Examples)

• Small home / warm climate: 1 shower + sink (≈3 GPM total). Electric (e.g., Tempra 36) or mid-size gas unit works well. In cooler groundwater, lean gas or accept staggered usage.
• Family of four / mixed fixtures: Two showers + dishwasher (≈5–6 GPM). Go 180k–199k BTU gas condensing, or plan staggered fixtures with electric.
• Multi-bath morning rush: Three simultaneous showers (~6–7.5 GPM). 199k BTU condensing gas is the comfort play; add recirculation for faster delivery.

Maintenance & Lifespan

Expect 15–20 years with annual flushing/descaling (more often with hard water). Clean inlet screens, check venting/condensate, and keep the area dust-free. Consider a whole-home filter or scale inhibitor if you see mineral build-up on faucets; your heat exchanger will thank you.

What You’ll Really Spend

Unit price: Small electric point-of-use units can be a few hundred dollars; whole-home electric and mid-size gas typically land in the low-to-mid thousands; premium condensing gas tops the category. Installation: Replacing a tank with tankless often runs more than a simple tank swap because of venting, gas-line upsizing, electrical work, and condensate drains. Budget realistically, get multiple quotes, and ask about permits.

How to Maximize Efficiency (and Rebates)

• Pick the right size so the burner/elements don’t run flat-out all the time.
• Use low-flow showerheads and fix leaky faucetsGPM saved is BTUs saved.
• Choose high-UEF condensing gas or high-efficiency electric; check federal and local incentives.
• Add recirculation smartly (timer or demand-based) to avoid wasting energy.

FAQs

Is tankless worth it?

If you need long, back-to-back showers or simultaneous fixtures, tankless shinesno “tank runs cold” moments. They also save space and can cut standby losses. In very cold groundwater, size up or go condensing gas for best comfort.

Do I need a water softener?

Not always, but hard water speeds scale build-up. If you see white crust on faucets, consider scale control (cartridge or softener) and plan regular flushes.

DIY or hire a pro?

Gas and venting codes, condensate handling, and electrical service upgrades make pro installation the safer, faster pathplus it protects warranty coverage.

Conclusion

For many homes, the Rinnai RU180iN or RE199iN delivers worry-free whole-house hot water. If you prefer electric, the Stiebel Eltron Tempra 36 Plus is the polished, quiet pick. Want condensing efficiency and recirculation in one package? Navien NPE-240A2 is tough to beat. Match the GPM to your fixtures, consider your climate’s temperature rise, and budget for a professional installyou’ll get spa-level showers without a storage tank hogging your utility room.

SEO Wrap-Up

sapo: Shopping for a tankless water heater? This guide distills Bob Vila’s favorite models and blends them with expert testing notes so you can pick the right unit the first time. We explain gas vs. electric, condensing vs. non-condensing, and how to size by GPM and temperature rise. You’ll see real-world cost ranges, maintenance must-dos, and when built-in recirculation is worth it. Whether you’re chasing lower bills, faster hot water, or boththese picks and pointers will help you install with confidence.

Real-World Experiences & Pro Tips (500-Word Deep Dive)

What homeowners notice first: the “first-use delay.” Even the best tankless units need a few seconds to fire and purge cool water in the line. If your primary bath sits far from the utility room, add a demand-controlled recirculation kit or choose a model with built-in recirc. It’s the difference between “meh” and “magic” when you turn the tap.

About that morning rush: Families often underestimate concurrent demand. Two showers and a kitchen sink can stress a mid-size non-condensing model in cold climates. Size up to a 199k BTU condensing unit (or set house rules like staggering dishwasher runs). If you prefer electric, be realistic: in northern states with 40–50°F groundwater, an electric whole-home unit may require dialing back flow or raising fixture aerator efficiency.

Electrical surprises: Whole-home electric units are wonderfully simpleno venting, no gasbut many older panels lack the spare amperage. Pros routinely install new breakers and sometimes upgrade service. Costs vary wildly by region; get bids from both plumbers and electricians before you buy the unit so you don’t blow your budget after checkout.

Gas-line realities: Tankless burners are powerful. If you’re replacing a 40- or 50-gallon atmospheric tank with a 180k–199k BTU tankless, your existing ½-inch gas line may be too small for the run length. Pros will compute pressure drop and often upsize sectionsanother reason quotes for “simple swaps” balloon during site visits.

Hard water = hard life (for heat exchangers): A year in hard-water territory can coat heat exchangers, reduce flow, and cause temperature swings. Keep a bucket, pump, and descaler on hand (or pay the pro) for an annual flush. If water spots on glass are your norm, plan more frequent maintenance. Many owners install a scale-reduction cartridge downstream of the main shutoffcheap insurance for smooth temperature control.

Noise & placement: Most modern units are quiet, but not silent. On shared walls with bedrooms, even a gentle burner “whoosh” or fan spin-up can be noticeable at 2 a.m. when someone sneaks a shower. If possible, put the unit on a garage or utility wall, or add vibration pads and flexible connectors to reduce sound transmission.

Recirculation done right: Timers that run 24/7 waste energy. Motion-activated or push-button (demand) recirc keeps standby losses tiny while delivering near-instant hot water. In long rambler-style homes, a small dedicated return line plus demand control feels luxurious without torpedoing efficiency.

Venting & condensate tips: Condensing models vent cooler exhaust (often via PVC) but add a condensate drain. Neutralizing cartridges prevent acidic condensate from nibbling at drainscheap, easy, and good for code compliance. Keep vent runs short with gentle elbows and mind termination clearances (soffits, windows, property lines) to pass inspection the first time.

Smart settings pay off: Set outlet water temperature thoughtfully (e.g., 120°F) and let your fixtures mix less. That preserves flow capacity and reduces scald risk. Many units also support vacation/eco modes; use them. If you have a Wi-Fi module, monitor usage for a monthyou’ll learn your true peak GPM and can tweak habits accordingly.

When to consider two units: Large homes with long pipe runs or multiple luxury showers might be better served by two smaller units (zoned for east/west wings or up/down floors). The upfront cost rises, but so does comfort and redundancy; a failure doesn’t freeze your entire household.

Bottom line from the field: The happiest owners matched size to climate, added smart recirculation, and committed to simple annual maintenance. Do those three thingsand pick one of the proven models aboveand you’ll love life without a tank.