Propane tankless · Ranein

Ranein RH8K-LPG-FC-RATING 80,000 BTU Propane Tankless Water Heater

80,000 BTU/h propane tankless, about 2.7 GPM at a 45°F rise

3.6 GPM max80,000 BTU/h~1.8 GPM at 70°F risePropane

Updated October 2026

The short answer

A sensible propane tankless for one shower at a time in cold climates.

Delivers
80,000 BTU/h input.
Watch for
Needs a gas line sized for the load.
Suits
One shower at a time in cold climates.
Max flow (maker)
3.6 GPM
Input (maker)
80,000 BTU/h
Voltage
120 V AC
Fuel
propane
Material
Propane
Dimensions (seller)
13.8"W x 21.7"H
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What it delivers

The Ranein RH8K-LPG-FC-RATING 80,000 BTU Propane Tankless Water Heater is a propane tankless with a 80,000 BTU/h burner and a stated maximum flow of 3.6 GPM.

Worked out from its input, it delivers roughly 2.7 GPM when the water only has to rise 45°F, and 1.8 GPM at a 70°F winter rise: 1 shower at 2 GPM in summer, less than one 2 GPM shower in winter. Size it to your fixtures and climate.

Gas load at full fire: about 0.9 gallons of propane an hour. An older half-inch line that already feeds a furnace often can't spare that, so have a gas fitter check the pipe size and run.

Non-condensing indoor units run hot exhaust and vent in the maker's listed vent system (often stainless Category III), which costs more than plastic.

Other listed details: features: LED Display; material: Propane; model: RH8K-LPG-FC-RATING; warranty: 2 Year Manufacturer.

The listing gives dimensions of 13.8 in (W) x 21.7 in (H) and a weight of 18 lb.

Warranty, per the listing: 2 Year Manufacturer.

Right unit for this house?

Install it when

  • One shower at a time in cold climates
  • Propane homes
  • Replacing a gas tank heater

Look at another unit when

  • More than 1 winter shower at once
  • Homes without a gas line

Strengths and trade-offs

Strengths

  • 80,000 BTU/h input
  • Up to 3.6 GPM

Trade-offs

  • Needs a gas line sized for the load
  • Stainless venting costs more
  • Scale builds up without flushing

Install limits

  • Figures are the maker's or seller's own. Flow at a rise is our estimate from the input; gas, venting and electrical work needs a licensed professional.

Rated performance

Every figure below comes from the source shown in brackets. Where the maker doesn't state something, we say so instead of estimating.

Model numberRH8K-LPG-FC-RATINGRetailer
Dimensions (seller)13.8"W x 21.7"HRetailer
Features (seller)LED DisplayRetailer
Voltage120 V ACRetailer
Max flow (maker)3.6 GPMRetailer
Input (maker)80,000 BTU/hRetailer
Product weight18 lbRetailer
MaterialPropaneRetailer
Warranty2 Year ManufacturerRetailer
FuelpropaneRetailer

Rival units at this flow

More gas tankless water heaters rated for similar demand

Full gas tankless water heaters spec grid · Every Ranein unit in the catalog

Final verdict

A sensible propane tankless for one shower at a time in cold climates.

Buy this unit

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Prices change often; the button shows today's price.

Each button opens this exact model. We may earn a commission on tracked links; it never changes what we publish. Disclosure

Questions buyers ask

How many showers can the Ranein RH8K-LPG-FC-RATING 80,000 BTU Propane Tankless Water Heater run at once?
From its 80,000 BTU/h input we estimate about 2.7 GPM at a 45°F rise and 1.8 GPM at a 70°F rise, so 1 two-GPM shower with mild inlet water and 0 in a cold winter. The maker's flow chart for this model is the final word.
What size gas line does the Ranein RH8K-LPG-FC-RATING 80,000 BTU Propane Tankless Water Heater need?
At full fire it uses about 77 cubic feet of natural gas an hour or 0.9 gallons of propane. The pipe size depends on the length of the run and every other gas appliance on it; the maker's manual and a licensed gas fitter decide it.