Skip to content

Eccotemp 45HI-LP + Vertical Vent Kit, Indoor Propane Tankless Water Heater

Original price $917.00 - Original price $936.95
Original price
$917.00 - $936.95
Current price $917.00


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

140,000 BTU heater for homes with up to 2 bathrooms
plus Through-Roof Vent Kit for Liquid Propane

Eccotemp 45HI-NG Indoor Natural Gas 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 vertical bundle.

All the basic venting pieces for a standard vertical to roof installation are included.

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 + Vertical Vent Kit, Indoor Propane Tankless Water Heater


• LPG propane powered
• 110 volt UL listed power cord
• 10 year warranty on heat exchanger, 5 year on parts
• CSA certified for use in Canada and USA
• 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"
• 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: 39 lbs
• Dimensions: 22" x 15" x 6"
• Energy rating: 82%
• Energy Factor: 0.80
• Hot water capacity: 1.2 - 6.8 GPM
• Minimum water pressure: 14 psi
• Minimum water flow rate: 0.75 GPM
• Power requirements: 120V AC, 60Hz, 2 Amps

Download the Use & care manual here.

Included: Vertical Vent Kit with 4" Diameter Single Walled Stainless Steel

Made in USA by Z-Flex Z-Vent with lifetime warranty. Includes all the basic components for a quick and easy installation.

Your installation will probably require additional Z-Vent pieces to reach your ceiling and roof, as follows:
≈ Determine how many additional feet to reach the roof. Buy that length of straight pipe.
Condensation drain pipe may be required depending on your water heater manual guidelines and building code.

Contact us if you need to buy additional Z-Vent parts or assistance, or browse our Venting section at the top of this web page.

Note this heater allows for a maximum vent run of 20 feet, subtracting 4 feet for each 90° elbow in the run.

Included pieces

  • qty 1 4" diameter Universal Appliance Adapter
  • qty 1 4" backflow preventer (included in the UAA above)
  • qty 1 4" Vertical drain pipe
  • qty 1 4" adjustable roof flashing. Unless you specify differently, we will ship the normal 30° roof slope flashing.
  • qty 1 4" top support, storm collar
  • qty 1 4" rain cap

The USA-made stainless steel is AL-294C alloy with a lifetime warranty from Z-Flex, and is Category II/III and UL approved.

FAQ ("Frequently Asked Question")

Q1: Can I convert this to natural gas from propane?
A1: No, sorry, according to Eccotemp.

Q2: Is the heated output water potable (drinkable)?
A2: 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.