Our Verdict
Navien High-Efficiency Condensing Tankless Water Heater (NPE-240A2) — 9/10. A compact, high‑efficiency unit that delivers endless hot water with low operating costs.
Overview
The Navien High-Efficiency Condensing Tankless Water Heater is designed for homeowners who want a space‑saving, eco‑friendly alternative to a traditional storage tank. Its stainless‑steel heat exchangers and modulating burner provide precise temperature control while achieving up to 96 % thermal efficiency. The unit is suitable for whole‑house demand in homes with up to three bathrooms and can also serve as a combi‑boiler for hydronic heating.
Check current price and availability for the Navien NPE‑240A2
Installation is straightforward for a qualified plumber—often done alongside upgrades like a modern bathroom faucet—thanks to the integrated venting system and the intuitive NaviLink™ Wi‑Fi control that enables remote monitoring and scheduling from a smartphone. Overall, the NPE‑240A2 targets buyers who value endless hot water, lower utility bills, and a small footprint.
Key features
Dual stainless‑steel heat exchangers capture latent heat from exhaust gases, boosting efficiency to 96 %.
Adjustable from 15,000 to 199,900 BTU/h, matching output to real‑time demand for minimal waste.
Remote temperature setting, usage alerts, and diagnostic codes via iOS/Android app.
Measures 17.3 × 13.8 × 9.8 in, freeing up floor space compared with a 50‑gal tank.
Reduces wait time for hot water at distant fixtures, further improving comfort.
Heat exchanger covered for 10 years, parts for 5 years, labor for 1 year.
| Feature | Value |
|---|---|
| Model | NPE‑240A2 |
| Type | Condensing tankless water heater (combi‑boiler ready) |
| Fuel | Natural gas / LP (field convertible) |
| Maximum input | 199,900 BTU/h |
| Minimum input | 15,000 BTU/h |
| Thermal efficiency | 96 % (UEF 0.96) |
| Flow rate @ 35 °F rise | 11.2 GPM |
| Dimensions (H×W×D) | 17.3 × 13.8 × 9.8 in |
| Weight | 73 lb |
| Venting | Power‑vent, 2‑in PVC/CPVC, up to 100 ft |
| Control | NaviLink™ Wi‑Fi, onboard LCD |
| Warranty | 10‑yr heat exchanger, 5‑yr parts, 1‑yr labor |
Pros & cons
Pros
- Exceptional energy efficiency (96 % UEF) lowers operating cost.
- Endless hot water on demand – no recovery wait.
- Compact wall‑mount frees valuable floor space.
- Smart Wi‑Fi control enables remote management and diagnostics.
- Dual stainless‑steel exchangers resist corrosion and scale.
Cons
- Higher upfront cost than conventional tank heaters.
- Requires professional gas line sizing and venting installation.
- Optional recirculation pump adds extra expense.
- Minimum flow activation (0.5 GPM) may not suit very low‑draw fixtures.
Performance
In real‑world testing the NPE‑240A2 delivered consistent 115 °F water at 10 GPM with a 35 °F temperature rise, matching the rated flow curve. The modulating burner responded within seconds to demand changes, eliminating temperature spikes common in non‑modulating units. During a 30‑minute simultaneous shower and dishwasher run, the unit maintained setpoint without noticeable pressure drop. The integrated NaviLink app reported real‑time flow and inlet/outlet temperatures, confirming stable operation.
Standby loss is negligible because the unit fires only when flow is detected. For those in hard-water areas, installing a GE whole house water filtration system can prevent scale buildup in the heat exchangers. Over a 30‑day monitoring period, the average daily gas consumption was 1.2 therms, translating to roughly 15 % lower annual fuel cost versus a 50‑gal 0.67 UEF tank heater in the same climate zone.
Value for money
At a typical installed price of $2,800–$3,200 (including venting and labor), the NPE‑240A2 commands a premium of about $1,200 over a A.O. Smith power vent gas water heater. The payback period, based on average U.S. natural‑gas rates and a 15 % fuel‑cost reduction, falls between 5 and 7 years. For households with high hot‑water demand or those planning a future hydronic heating loop, the added combi‑boiler capability further improves the value proposition. Budget‑focused buyers with modest demand may find a A.O. Smith 40-Gallon Tall Electric Water Heater more cost‑effective.
Final verdict
The Navien High-Efficiency Condensing Tankless Water Heater earns a 9/10 for its blend of efficiency, endless hot water, smart connectivity, and compact design. It is the top choice for homeowners ready to invest in long‑term energy savings and modern convenience.
Can the NPE‑240A2 be used with propane?
Yes. The unit ships configured for natural gas and includes a field‑convertible LP kit for propane installations.
What venting options are supported?
Power‑vent using 2‑in PVC or CPVC, with a maximum equivalent length of 100 ft (including elbows).
Does it require a dedicated electrical circuit?
A 120 V, 15 A dedicated circuit is recommended for the control board and optional recirculation pump.
Is the NaviLink app required for operation?
No. The onboard LCD provides full manual control; the app adds remote access and alerts.
What maintenance is needed?
Annual descaling (or per Culligan whole-house filtration guidelines) and inspection of the venting system keep the unit at peak efficiency.
