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

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

Eccotemp 45HI-LP Indoor Liquid Propane Tankless Water Heater


• Liquid propane powered
• 110 volt UL listed power cord
• 10 year warranty on heat exchanger
• CSA certified for Canadian and USA use
• Power vented: includes internal exhaust fan
• Integrated freeze protection (Will not prevent freezing in all conditions. See manual.)
• Optional: Digital remote with diagnostics and simple controls


• Water/gas connections: 3/4 inch water inlet/outlet, gas inlet
• Venting: 4" diameter pipe
• Flow Rate:
→ 35 degree rise: 6.8 GPM
→ 50 degree rise: 5.0 GPM
→ 70 degree rise: 3.4 GPM
• Minimum gas rate: 19,800 BTUs
• Maximum gas rate: 140,000 BTUs
• Weight: 38 lbs
• Dimensions: 22" x 15" x 6"
• Energy rating: 82%
• Energy Factor: 0.80
• 5 year warranty on parts
• Hot water capacity: 0.8 - 6.8 GPM
• Minimum water pressure: 14 psi
• Minimum water flow rate: 0.75 GPM
• Power requirements: 120V AC, 60Hz, 2 Amps

Download here the Use & care manual.

Venting: If you need to buy Z-Vent parts, browse our Venting section at the top of this web page. FYI, this heater allows for a maximum vent run of 20 feet, subtracting 4 feet for each 90° elbow in the run.

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 to natural gas from 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.