Canada-wide gas boiler information · On-site service in Greater Vancouver, BC
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Comparison
Verdict in brief
The TK-540P-NIH and TK-540P-NEH are the indoor and outdoor natural-gas versions of the same condensing tankless water heater: both fire 15,000 to 199,000 BTU/h with 10 GPM and 3/4" NPT connections, but the indoor model prints 0.93 UEF at 71 lb while the outdoor model prints 0.95 UEF at 69 lb.
Published manufacturer figures. Input and output are kept separate; blanks mean the manufacturer did not publish that value.
| Specification | Takagi TK-540P-NIH | Takagi TK-540P-NEH |
|---|---|---|
| Input, minimum | 15,000 BTU/h | 15,000 BTU/h |
| Input, maximum | 199,000 BTU/h | 199,000 BTU/h |
| Uniform Energy Factor (UEF) | 0.93 UEF | 0.95 UEF |
| Maximum flow rate | 10 GPM | 10 GPM |
| Weight | 71 lb | 69 lb |
| Installation | Indoor | Outdoor |
The TK-540P-NIH and TK-540P-NEH share the same rating row on Takagi's specification sheet TRGSS00116: 15,000 to 199,000 BTU/h on natural gas, 10 GPM maximum flow, 15–150 PSI water pressure and 3/4" NPT hot/cold and gas connections in a 23-5/8 × 17-3/4 × 11-1/4 in cabinet. Both are condensing tankless water heaters with integrated recirculation pumps — DHW-only appliances, not boilers.
The differences are efficiency and package: the indoor NIH prints 0.93 UEF and 71 lb and ships with integrated temperature and pump controls, advanced diagnostics and a factory-installed power cord; the outdoor NEH prints 0.95 UEF and 69 lb, ships with a wall-mount temperature remote controller and is ENERGY STAR qualified.
Elevation certification also differs: indoor models are certified to 10,100 ft and outdoor models to 6,000 ft per the specification sheet. Both support Easy-Link with up to three other T-H3 units and common venting up to 8 units.
Takagi
The Takagi TK-540P-NIH is a condensing tankless water heater — a DHW-only appliance, not a boiler — firing 15,000 to 199,000 BTU/h on natural gas with 0.93 UEF and up to 10 GPM.
Takagi
The Takagi TK-540P-NEH is a condensing tankless water heater — a DHW-only appliance, not a boiler — firing 15,000 to 199,000 BTU/h on natural gas with 0.95 UEF and up to 10 GPM.
The outdoor NEH prints 0.95 UEF against the indoor NIH's 0.93, and the specification sheet marks the outdoor pair as ENERGY STAR qualified.
No. Indoor models include integrated temperature and pump controls with advanced diagnostics and a factory-installed power cord; outdoor models ship with a wall-mount temperature remote controller.
No. They are condensing tankless water heaters with integrated recirculation for domestic hot water only; Takagi's catalogue contains no boiler line.
A consultation includes a heat-loss review so the size is right the first time.
On-site service in Greater Vancouver, BC. ROMA lists “Open 7 days” on its site; call to confirm same-day availability.
Sources and verification
Facts checked September 9, 2026. Last updated September 9, 2026. Technical reviewer: not yet assigned.