Navien · NPE-S2 condensing tankless (NPE-180S2 / NPE-210S2 / NPE-240S2) · Gas tankless
Navien NPE-180S2
The Navien NPE-180S2 is the smallest of Navien's current S2 condensing tankless models: 10,000–150,000 BTU/h on natural gas or propane, UEF 0.96, and published flows of 8.4 GPM at a 35 °F rise and 4.3 GPM at a 67 °F rise.
Key figures
- Max input
- 150,000 BTU/h
- Flow at 35 °F (19.4 °C) rise
- 8.4 GPM (31.8 L/min)
- Uniform Energy Factor (UEF)
- 0.96
Flow figures depend on temperature rise; compare only at the same rise. Max flow is not guaranteed winter performance.
Navien NPE-180S2 in practice
The NPE-180S2 is the entry size of Navien's S2 platform, suited to the home or suite whose peak fits a 150,000 BTU/h input: 8.4 GPM (31.8 L/min) at a 35 °F rise and 4.3 GPM (16.3 L/min) at a 67 °F rise. Because the Metro Vancouver winter rise to a 49 °C shower approaches 40 °C (72 °F), the winter-class figure makes this a one-fixture-at-a-time unit in January for most homes.
It shares the S2 platform's forced-draft direct venting, 3/4 in connections and 120 V operation, and at 68 lb (30.8 kg) it is the lightest S2 model. Whether CANRO stocks this model for a given job is confirmed at consultation.
Best suited to
- Small houses, suites and laneway homes with sequential demand
- One-bathroom households wanting a compact current-generation condensing unit
- Conversions where the gas supply and vent route suit the smallest S2 input
Limitations to know
- Winter delivery at a 67 °F-class rise is 4.3 GPM: one fixture at a time in January
- Requires 120 V power; no hot water during an outage
- Needs a sealed 2 in or 3 in vent route and a condensate drain
- Navien's published resale policy voids warranty for internet or e-commerce purchases; supply runs through contractors
Applicability and support
- Model number
- NPE-180S2
- Variants on this page
- None
- Canadian availability
- available
- Production status
- current
- CANRO supplies
- Confirmed at consultation
- CANRO services
- Confirmed at consultation
- Recirculation
- Yes, external pump and piping required
- Warranty
- Not verified
The S2 platform supports Navien's recirculation configuration with an external pump or crossover accessory, as on the A2; energy consumption rises when recirculation is configured.
Where CANRO provides on-site service
On-site service is currently offered across Metro Vancouver: Vancouver, Burnaby, Richmond, Surrey, Coquitlam, North Vancouver, West Vancouver, New Westminster, Delta, Langley, Port Moody, Port Coquitlam, Maple Ridge, Pitt Meadows, White Rock, Tsawwassen; plus Anmore, Belcarra, Lions Bay, Bowen Island, Abbotsford with travel or ferry arrangements confirmed by phone. Everything else on this site is reference information you can use anywhere in Canada.
Specifications
Published specifications
Values as published by Navien. Manufacturer gallon and BTU/h figures are preserved with metric alongside; notes flag conflicting documents and missing figures. Groups expand for detail.
Flow (tankless) 4
| Specification | Value | Note |
|---|---|---|
| Flow at a 35 °F (19.4 °C) rise | 8.4 GPM (31.8 L/min) at 35 °F (19.4 °C) rise | Navien's published rating table. |
| Flow at a 45 °F (25 °C) rise | 6.5 GPM (24.6 L/min) at 45 °F (25 °C) rise | Navien's published rating table. |
| Flow at a 67 °F (37.2 °C) rise | 4.3 GPM (16.3 L/min) at 67 °F (37.2 °C) rise | Navien's published rating table; the winter rise in Metro Vancouver is in this range. |
| Minimum flow rate | 0.5 GPM (1.9 L/min) | Per Navien's specification table. |
Input 2
| Specification | Value | Note |
|---|---|---|
| Minimum gas input | 10,000 BTU/h | 2.9 kW. Natural gas and propane per Navien. |
| Maximum gas input | 150,000 BTU/h | 44.0 kW. Natural gas and propane per Navien. |
Efficiency 1
| Specification | Value | Note |
|---|---|---|
| Uniform Energy Factor (UEF) | 0.96 | Natural gas and propane per Navien's specification table. |
Venting and air 1
| Specification | Value | Note |
|---|---|---|
| Vent type | 2 in or 3 in PVC, CPVC, approved polypropylene or stainless steel; special gas vent type BH (Class II A/B/C) | Forced-draft direct vent per Navien; zero clearance to combustibles. |
Connections 2
| Specification | Value | Note |
|---|---|---|
| Gas connection | 3/4 in | NG supply pressure 3.5–10.5 in. w.c.; propane 8–13 in. w.c. |
| Water connections | 3/4 in cold inlet and hot outlet |
Electrical 1
| Specification | Value | Note |
|---|---|---|
| Electrical supply | 120 V AC, 60 Hz |
Physical 4
| Specification | Value | Note |
|---|---|---|
| Height | 27.4 in (696 mm) | |
| Width | 17.3 in (439 mm) | |
| Depth | 13.2 in (335 mm) | |
| Weight | 68 lb (30.8 kg) |
Operating limits 2
| Specification | Value | Note |
|---|---|---|
| Maximum altitude | 10,100 ft for natural gas and propane | Per Navien; the installation manual has the details. |
| Safety devices | Flame rod, air-pressure switch, ignition-operation detector and high-limit devices per Navien's specification table |
Manuals
Maintenance the manufacturer specifies
- Flush (descale) the heat exchanger periodically per Navien's maintenance guidance; scale damage is not covered by warranty.
- Clean the water inlet filter as part of the service interval.
- Check the condensate drain and trap for flow and blockage at service.
- Confirm the correct vent material and lengths from the installation manual before any vent work.
Fault codes documented for this model
None documented yet.
Services
Hot water and scalding
- Water above 49 °C at a tap can scald in seconds, and children and older adults are at most risk. BC's plumbing code limits shower and bathtub water to 49 °C.
- Storage tanks are normally kept hotter (Health Canada advises 60 °C) to limit Legionella growth, with a thermostatic mixing valve tempering the water to the fixtures.
- Never bypass or remove a mixing valve, thermostat or high-limit control to get hotter water.
Official guidance: Government of Canada on water temperature and scalds and HealthLinkBC.
Frequently asked questions
Is the NPE-180S2 sold in Canada?
Yes. Navien's Canadian site lists the NPE-S2 series with the NPE-180S2 among its residential water heaters.
Can the NPE-180S2 run two showers in winter?
At its 67 °F-rise rating of 4.3 GPM it cannot serve two shower-class fixtures at once in January; the honest option for that demand is a larger S2 model or a demand assessment.
What venting does the NPE-180S2 need?
The S2 platform's 2 in or 3 in PVC, CPVC, approved polypropylene or stainless venting (or BH special gas vent) as a forced-draft direct vent.
Questions about the Navien NPE-180S2?
Describe what the water heater is doing and get a straight answer about the next step.
On-site service in Metro Vancouver, BC. Call to check availability.
Sources and verification
- Navien — NPE-180S2 product page and specifications · Canadian source · accessed September 7, 2026
- Navien — Canadian site (NPE-S2 Series listed) · Canadian source · accessed September 7, 2026
Facts checked September 7, 2026. Last updated September 7, 2026. Technical reviewer: not yet assigned.