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Eccotemp 45H-NG Outdoor Natural Gas Tankless Water Heater

Original price $699.00 - Original price $718.95
Original price
$699.00 - $718.95
Current price $699.00


On backorder until 31st May 2023; Backorder dates can change at any time.

140,000 BTU heater for homes with up to 2 bathrooms

Eccotemp 45H-NG Outdoor Natural Gas Tankless Water HeaterThe 45H is the outdoor equivalent of the 45HI Eccotemp indoor tankless water heater. It is designed to provide hot water to standard three bedroom, two bathroom homes. The 45H-NG is for outdoor Natural Gas installations only. For Liquid Propane applications, please see the 45H-LP.

Rated at an impressive 6.8 GPM, the 45H is adaptable to split systems, which can further increase hot water delivery speed and efficiency. The 45H is the ideal choice for standard sized homes, thanks to its fully automated control system.


• Natural gas powered
• 110 volt UL listed power cord
• CSA certified for use in USA and Canada
• Power vented: includes internal exhaust fan
• Integrated freeze protection (Will not prevent freezing in all conditions. See manual.)
• Digital remote with diagnostics and simple controls


• Water/gas connections: 3/4 inch water inlet/outlet and gas inlet
• Flow Rate:
→ 35° rise at 6.8 GPM
→ 50° rise at 5.0 GPM
→ 70° rise at 3.4 GPM
• Minimum gas rate: 19,800 BTUs
• Maximum gas rate: 140,000 BTUs
• Weight: 38 lbs
• Dimensions: 24" x 15" x 5"
• Energy rating: 82%
• Energy Factor: 0.80
• 5 year warranty on parts. 10 year warranty on heat exchanger
• Hot water capacity: 0.8 to 6.8 GPM
• Minimum water pressure: 14 psi
• Minimum water flow rate: 0.75 GPM
• Power requirements: 110V AC, 60Hz, 2 Amps

Use & care manual

Frequently Asked Question ("FAQ")

Q1: What is the difference between the 40H and the 45H?
A1: The 45HI has a lower turn-on flow rate of 0.8 GPM, is smaller and lighter, and has updated self-diagnostics. The 45HI maintains the same connections and water heating capacity as the 40H.

Q2: Can I convert this from natural gas to propane?
A2: No, sorry, according to Eccotemp.

Q3: Is the heated output water potable (drinkable)?
A3: Yes. Eccotemp has tested the heated output water as acceptable according to water safety standards.

Q4: The manual states, "Unit not recommended for elevations in excess of 2,000 feet". Really? That's very low.
A4: Elsewhere Eccotemp states that the maximum elevation is 3000 ft. Using it at higher elevations will likely result in the error code E8 indicating insufficient oxygen mix for combustion. has other heaters that will work at higher elevations. Please ask if you need assistance with a selection.