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The best propane tankless water heater for cold climates keeps hot water flowing when the air outside turns bitter, and the picks here cover portable propane heaters and whole-house gas units for exactly that job. We compared what each listing states: flow, heat output, freeze protection and warranty terms. A portable propane heater suits a cabin or RV, while a larger gas unit suits a house with several outlets running at once.
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Quick picks
Best Overall GEARPASS 6.3 GPM Heater: 6.3 GPM, 160,000 BTU and a 2-year warranty stated Check price on Amazon
Best Portable Forimo 20L Propane Heater: 5.26 GPM and 68,000 BTU with CSA approved regulator Check price on Amazon
Most Compact VANSTON 6L Propane Heater: 9 lbs with a folding handle and 1.45 GPM Check price on Amazon
Whole House Pick Rheem RTG 7.0 GPM Heater: 7.0 GPM natural gas heater with CSA certification and freeze protection Check price on Amazon
Electric Alternative Rheem RTEX-11 Heater: 11kW electric heater with 2.68 GPM and no venting needed Check price on Amazon
The kits we chose
| # | Product | Solar Score | Buy |
|---|---|---|---|
| 1 | Forimo 20L Propane Heater | 9.6/10 | Buy on Amazon |
| 2 | GEARPASS 6.3 GPM Heater | 9.6/10 | Buy on Amazon |
| 3 | VANSTON 6L Propane Heater | 9.5/10 | Buy on Amazon |
| 4 | Rheem RTG 7.0 GPM Heater | 9.3/10 | Buy on Amazon |
| 5 | Rheem RTEX-11 Heater | 9.2/10 | Buy on Amazon |

Forimo 20L Propane Heater
A portable 20L propane tankless heater with 5.26 GPM, a CSA approved regulator and anti-freezing protection.
Pros
- 5.26 GPM output with a 68,000 BTU/hour maximum power output stated
- CSA approved regulator with flame failure, anti-freezing and overheating protection
- Needs only 3.6 PSI of water pressure to run
- 5 spray modes on the shower head with a 59-inch hose and a 5-foot gas regulator
Cons
- No warranty term is stated
- Propane only: it cannot run on natural gas
- Runs on 2 D-cell batteries, so the ignition needs batteries in the box
- Size of 17.12 by 7.87 by 26.77 inches needs a tall spot to mount or stand
Detailed Review
The listing states a 20L propane tankless heater with 5.26 GPM, a maximum power output of 68,000 BTU/hour and a maximum temperature rise of 167°F, needing only 3.6 PSI of water pressure. The regulator is CSA approved, and the heater states flame failure, anti-freezing and overheating protection. The size is stated as 17.12 by 7.87 by 26.77 inches, and the heater runs on 2 D-cell batteries. The kit includes a 5-foot gas regulator, a shower head with 5 spray modes, a 59-inch stainless steel hose and a shower holder. The maker gives two widths, 7.87 and 17.12 inches; check before ordering.
Who it's for: cabin and RV owners who want a portable propane heater with strong flow and CSA approved parts. Who should skip it: anyone who needs a warranty term on the listing, or a heater that runs on natural gas.
Its Solar Score of 9.6/10 comes from performance 30/35, build 21/25, value 21/25, safety 8/10 and warranty 0/5: 80 of 100 points, placed on our 9.2 to 9.8 scale.
Key Specifications
| Flow | 5.26 GPM |
|---|---|
| Power | 68,000 BTU/hour |
| Pressure | 3.6 PSI minimum |
| Size | 17.12 x 7.87 x 26.77 inches |
Taken from the seller's listing on 14 November 2026. Capacity and output figures are rated by the manufacturer.
Safety and Warranty
What this listing states. CSA approved regulator, flame failure device, anti-freezing and overheating protection stated, so safety scores 8 of 10. No warranty term, so warranty scores zero. See How We Pick.
Follow the manual. Connect and use the product as the maker describes, stay within every stated rating, and read the manual before first use.
This is general buying information, not professional advice. Follow each product manual and local rules, and see our Safety Disclaimer.

GEARPASS 6.3 GPM Heater
An indoor propane tankless heater with 6.3 GPM, 160,000 BTU and a 2-year warranty stated.
Pros
- 6.3 GPM output with 160,000 BTU heating capacity stated
- LED touchscreen with temperature control between 95°F and 140°F
- Oxygen-free copper heat exchanger with a stainless steel housing
- 2-year warranty stated, with G 1/2-inch water and gas connections
Cons
- No freeze protection is stated
- Propane only, and indoor use needs proper ventilation and exhaust installation
- Needs 110-120V AC power, so it is not a battery-only outdoor unit
- Indoor direct vent design means the install needs a vent route through a wall
Detailed Review
The listing states a propane tankless heater with up to 6.3 GPM and 160,000 BTU of heating capacity, for propane (LPG) only, with a water pressure range of 2.9 to 116 PSI. It has an LED digital display with touch control, an oxygen-free copper heat exchanger and a stainless steel housing, with G 1/2-inch water and gas connections and a 2.36-inch horizontal vent pipe. Input voltage is 110-120V AC through a US standard plug, and the maker states a 2-year warranty. The maker gives two top temperatures, 140°F and 149°F; check before ordering.
Who it's for: homeowners who want high propane flow indoors with a touchscreen and a 2-year warranty. Who should skip it: anyone who needs stated freeze protection, or a heater that runs without mains power.
Its Solar Score of 9.6/10 comes from performance 32/35, build 22/25, value 21/25, safety 0/10 and warranty 3/5: 78 of 100 points, placed on our 9.2 to 9.8 scale.
Key Specifications
| Flow | 6.3 GPM |
|---|---|
| Power | 160,000 BTU |
| Temperature | 95-140°F control |
| Pressure | 2.9-116 PSI |
Taken from the seller's listing on 14 November 2026. Capacity and output figures are rated by the manufacturer.
Safety and Warranty
What this listing states. No safety listing, protection or rating is stated, so safety scores zero. 2-year warranty stated. It does not say everything a buyer needs, such as who pays return shipping, so warranty scores 3 of 5. See How We Pick.
Follow the manual. Connect and use the product as the maker describes, stay within every stated rating, and read the manual before first use.
This is general buying information, not professional advice. Follow each product manual and local rules, and see our Safety Disclaimer.

VANSTON 6L Propane Heater
A portable 6L propane tankless heater with 1.45 GPM, freeze protection and a folding handle.
Pros
- 1.45 GPM of hot water within 5 seconds, per the maker
- 37,500 BTU/hr output with temperature adjustable up to 167°F
- Safety system with overheat, low-flow, dry-fire, freeze and flame failure protection
- 9 lbs with a folding handle, plus a shower head, gas regulator and mounting hardware
Cons
- No warranty term is stated
- 1.45 GPM suits a single shower, not several outlets at once
- Works from 7 PSI, so very low pressure sources may not start it
- Portable outdoor design, not a whole-house heater
Detailed Review
The listing states a portable 6L propane tankless heater with 1.45 GPM and up to 37,500 BTU/hr, giving hot water within 5 seconds and temperature adjustable up to 167°F. It weighs 9 lbs with a folding handle, works from 7 PSI up to 145 PSI, and states a safety system with overheat, low-flow, dry-fire, freeze and flame failure protection. Setup is stated at within 10 minutes, and the box includes a shower head, gas regulator, connectors and mounting hardware. The maker gives two weights, 9 lbs and 12.0 pounds; check before ordering.
Who it's for: campers and cabin owners who want a light portable propane heater for a single shower. Who should skip it: anyone who needs high flow for several outlets, or a warranty term on the listing.
Its Solar Score of 9.5/10 comes from performance 28/35, build 20/25, value 20/25, safety 7/10 and warranty 0/5: 75 of 100 points, placed on our 9.2 to 9.8 scale.
Key Specifications
| Flow | 1.45 GPM |
|---|---|
| Power | 37,500 BTU/hr |
| Pressure | 7-145 PSI |
| Temperature | Up to 167°F |
Taken from the seller's listing on 14 November 2026. Capacity and output figures are rated by the manufacturer.
Safety and Warranty
What this listing states. Overheat, low-flow, dry-fire, freeze and flame failure protection stated, so safety scores 7 of 10. No warranty term, so warranty scores zero. See How We Pick.
Follow the manual. Connect and use the product as the maker describes, stay within every stated rating, and read the manual before first use.
This is general buying information, not professional advice. Follow each product manual and local rules, and see our Safety Disclaimer.

Rheem RTG 7.0 GPM Heater
A natural gas tankless heater with 7.0 GPM, 160,000 BTU and CSA certification for whole-house use.
Pros
- 7.0 GPM at a 35°F temperature rise with 160,000 BTU/hr output
- CSA Certified with freeze protection, flame failure protection and a multi-point safety system
- LeakGuard leak detection and prevention stated
- Digital LED control with precision ±1°F adjustments
Cons
- Natural gas only: it cannot run on propane
- Indoor installation with a direct vent system, so it needs a vent route
- 1 Year Labor coverage is short beside the 15-year heat exchanger term
- 46.5 pounds and a wall-mount design need a sturdy mounting point
Detailed Review
This is a natural gas heater, not a propane heater. The listing states 7.0 GPM at a 35°F temperature rise with 160,000 BTU/hr output, for 2-3 simultaneous showers, with a 0.82 UEF. It is CSA Certified, with built-in freeze protection, flame failure protection and a multi-point safety system, plus LeakGuard leak detection and prevention. The digital LED panel adjusts temperature in ±1°F steps, and the size is stated as 10.27 by 13.5 by 24.2 inches at 46.5 pounds. Coverage is stated as 15 years on the heat exchanger and 5 years on parts, with 1 year on labor.
Who it's for: homes on a natural gas line that want whole-house tankless hot water with strong safety cover. Who should skip it: anyone who needs propane, since this heater runs on natural gas only.
Its Solar Score of 9.3/10 comes from performance 19/35, build 20/25, value 12/25, safety 8/10 and warranty 4/5: 63 of 100 points, placed on our 9.2 to 9.8 scale.
Key Specifications
| Flow | 7.0 GPM at 35°F rise |
|---|---|
| Power | 160,000 BTU/hr |
| Efficiency | 0.82 UEF |
| Weight | 46.5 pounds |
Taken from the seller's listing on 14 November 2026. Capacity and output figures are rated by the manufacturer.
Safety and Warranty
What this listing states. CSA Certified, freeze protection, flame failure protection and LeakGuard leak detection stated, so safety scores 8 of 10. 15-year heat exchanger and 5-year parts warranty stated. It does not say everything a buyer needs, such as who pays return shipping, so warranty scores 4 of 5. See How We Pick.
Follow the manual. Connect and use the product as the maker describes, stay within every stated rating, and read the manual before first use.
This is general buying information, not professional advice. Follow each product manual and local rules, and see our Safety Disclaimer.

Rheem RTEX-11 Heater
An 11kW electric tankless heater with up to 2.68 GPM, digital controls and no venting required.
Pros
- 11kW electric heat with up to 2.68 GPM for multiple fixtures
- Digital thermostatic controls in 1-degree increments from 80°F to 140°F
- No venting required, with a compact 12.63 by 8.25 by 3.63 inch size
- 5-Year Leak and 1-Year Parts warranty stated
Cons
- Electric, not propane: it needs a 240V supply and a 50-amp breaker
- 2.68 GPM covers multiple fixtures but trails the gas heaters here on flow
- Needs a minimum 100-amp household electrical service panel
- No freeze protection is stated
Detailed Review
This is an electric heater, not a propane heater. The listing states an 11kW tankless electric heater on 240V, with up to 2.68 GPM and digital thermostatic controls in 1-degree increments from 80°F to 140°F. It needs a 50-amp double-pole breaker, a set of #8 AWG copper conductors with ground, and a recommended minimum 100-amp household electrical service panel. No venting is required, and the size is stated as 12.63 by 8.25 by 3.63 inches. Coverage is stated as 5 years on leaks and 1 year on parts. A licensed electrician should install it.
Who it's for: homes with 240V capacity and a 100-amp panel that want compact electric hot water without venting. Who should skip it: anyone who needs propane heat, or a cabin without a 240V supply.
Its Solar Score of 9.2/10 comes from performance 18/35, build 20/25, value 16/25, safety 0/10 and warranty 3/5: 57 of 100 points, placed on our 9.2 to 9.8 scale.
Key Specifications
| Power | 11 kW, 240V |
|---|---|
| Flow | Up to 2.68 GPM |
| Temperature | 80-140°F, 1-degree increments |
| Breaker | 50-amp double-pole, #8 AWG |
Taken from the seller's listing on 14 November 2026. Capacity and output figures are rated by the manufacturer.
Safety and Warranty
What this listing states. No safety listing, protection or rating is stated, so safety scores zero. 5-Year Leak, 1-Year Parts warranty stated. It does not say everything a buyer needs, such as who pays return shipping, so warranty scores 3 of 5. See How We Pick.
Follow the manual. Connect and use the product as the maker describes, stay within every stated rating, and read the manual before first use.
This is general buying information, not professional advice. Follow each product manual and local rules, and see our Safety Disclaimer.
As an Amazon Associate I earn from qualifying purchases.
More picks to compare
Forimo 18L Propane Heater4.74 GPM propane heater with CSA approved regulator for camping trips.Check on Amazon
QERPRE 4.3 GPM Heater4.3 GPM propane heater for 2-3 water points with multi-protection.Check on Amazon
LiberLive 6L Propane Heater1.58 GPM portable heater with CSA certification and a 1-year warranty.Check on Amazon
Rheem RTG 7.0 GPM Propane7.0 GPM outdoor propane heater with freeze protection and CSA certification.Check on Amazon
VELPAX 4.76 GPM Heater4.76 GPM outdoor propane heater with a remote control panel.Check on Amazon
Numbers side by side
| Heater | Solar Score | Flow | Heat output | Freeze protection | Warranty | Amazon |
|---|---|---|---|---|---|---|
| Forimo 20L Propane Heater | 9.6/10 | 5.26 GPM | 68,000 BTU | Anti-freezing protection | Not stated | View on Amazon |
| GEARPASS 6.3 GPM Heater | 9.6/10 | 6.3 GPM | 160,000 BTU | Not stated | 2 Year | View on Amazon |
| VANSTON 6L Propane Heater | 9.5/10 | 1.45 GPM | 37,500 BTU | Freeze protection | Not stated | View on Amazon |
| Rheem RTG 7.0 GPM Heater | 9.3/10 | 7.0 GPM | 160,000 BTU | Freeze protection | 15-year exchanger, 5-year parts | View on Amazon |
| Rheem RTEX-11 Heater | 9.2/10 | 2.68 GPM | 11 kW | Not stated | 5-Year Leak, 1-Year Parts | View on Amazon |
We copied each rating from the seller’s listing as the brand states it; data date 14 November 2026.
Where the points went
The Solar Score weighs performance, build, value, safety and warranty. For a tankless water heater, safety means CSA approval and stated freeze, flame failure and overheat protection; a heater that states none of those scores zero on that line, whatever its flow. 3 of the 5 heaters state a warranty term, and only the GEARPASS heater states a 2-year term. How we pick explains the weights.
| Product | Solar Score | Perf. /35 | Build /25 | Value /25 | Safety /10 | Warranty /5 |
|---|---|---|---|---|---|---|
| Forimo 20L Propane Heater | 9.6 | 30 | 21 | 21 | 8 | 0 |
| GEARPASS 6.3 GPM Heater | 9.6 | 32 | 22 | 21 | 0 | 3 |
| VANSTON 6L Propane Heater | 9.5 | 28 | 20 | 20 | 7 | 0 |
| Rheem RTG 7.0 GPM Heater | 9.3 | 19 | 20 | 12 | 8 | 4 |
| Rheem RTEX-11 Heater | 9.2 | 18 | 20 | 16 | 0 | 3 |
We place weighted points on a scale whose ends are 9.2 and 9.8. Because the mapping is straight, a unit with more points never shows less.
How to choose the best propane tankless water heater for cold climates
Start with flow and heat output
Flow sets how many outlets run at once, and heat output sets how far the heater lifts cold incoming water. The Rheem natural gas heater states 7.0 GPM at a 35°F temperature rise with 160,000 BTU/hr, and the GEARPASS propane heater states 6.3 GPM with 160,000 BTU. The forimo portable states 5.26 GPM with 68,000 BTU/hour, the VANSTON portable states 1.45 GPM with 37,500 BTU/hr, and the Rheem electric states up to 2.68 GPM from 11kW. For the wider propane comparison, see our best propane tankless water heater guide.
| Heater | Flow | Heat output |
|---|---|---|
| Forimo 20L Propane Heater | 5.26 GPM | 68,000 BTU |
| GEARPASS 6.3 GPM Heater | 6.3 GPM | 160,000 BTU |
| VANSTON 6L Propane Heater | 1.45 GPM | 37,500 BTU |
| Rheem RTG 7.0 GPM Heater | 7.0 GPM | 160,000 BTU |
| Rheem RTEX-11 Heater | 2.68 GPM | 11 kW |
Freeze protection matters most in cold climates
The forimo heater states anti-freezing protection, the VANSTON heater states freeze protection, and the Rheem natural gas heater states built-in freeze protection. The GEARPASS heater and the Rheem electric heater state no freeze protection, which is the gap that matters most for a cold-climate buyer. The VANSTON safety system also lists dry-fire and low-flow protection beside freeze protection, and the forimo heater adds flame failure and overheating protection. For the tank against tankless choice, see our propane tankless vs tank water heater guide.
Propane, natural gas or electric
3 of the 5 heaters here run on propane only: the forimo, GEARPASS and VANSTON models. The Rheem RTG heater runs on natural gas, so it suits a house with a natural gas line and not a propane cabin. The Rheem RTEX-11 runs on electricity, needs a 240V supply with a 50-amp breaker and a minimum 100-amp panel, and needs no venting at all. Match the fuel to what your cabin or house already has before comparing flow figures. For the solar against propane comparison, see our solar water heater vs propane tankless water heater guide.
Check the install needs before you buy
The GEARPASS heater is an indoor direct vent unit that needs proper ventilation and exhaust installation, and it plugs into a 110-120V AC outlet. The Rheem natural gas heater installs indoors with a direct vent system, and its listing says professional installation is required. The Rheem electric heater needs a 240V circuit, and a licensed electrician should install it. The portable propane heaters are simpler: the forimo heater runs on 2 D-cell batteries, and the VANSTON heater states setup within 10 minutes with its shower head, gas regulator and mounting hardware in the box.
Sizing Notes
- Match flow to outlets: 7.0 GPM for 2-3 simultaneous showers on the Rheem natural gas heater, 6.3 GPM on the GEARPASS heater, 5.26 GPM on the forimo heater and 1.45 GPM on the VANSTON heater.
- Match heat output to the rise you need: 160,000 BTU on the GEARPASS and Rheem natural gas heaters, 68,000 BTU/hour on the forimo heater and 37,500 BTU/hr on the VANSTON heater.
- Check freeze protection first in cold climates: anti-freezing protection on the forimo heater, freeze protection on the VANSTON and Rheem natural gas heaters, none stated on the GEARPASS and Rheem electric heaters.
- Check power and venting: 110-120V AC and direct vent on the GEARPASS heater, 240V with a 50-amp breaker on the Rheem electric heater, direct vent indoors on the Rheem natural gas heater.
FAQ: power away from the grid
Which heaters here run on propane?
The forimo, GEARPASS and VANSTON heaters run on propane only. The Rheem RTG heater runs on natural gas, and the Rheem RTEX-11 runs on electricity.
Which pick has the highest flow?
The Rheem natural gas heater, at 7.0 GPM with a 35°F temperature rise. The highest propane flow here is the GEARPASS heater at 6.3 GPM, ahead of the forimo heater at 5.26 GPM.
Which heaters state freeze protection?
The forimo heater states anti-freezing protection, the VANSTON heater states freeze protection, and the Rheem natural gas heater states built-in freeze protection. The GEARPASS and Rheem electric heaters state none.
What power does the GEARPASS heater need?
It runs on 110-120V AC through a US standard plug, and it needs proper ventilation and exhaust installation indoors.
Which pick states a 2-year warranty?
The GEARPASS heater, with a 2-year warranty stated. The Rheem natural gas heater states 15 years on the heat exchanger and 5 years on parts, with 1 year on labor, and the Rheem electric heater states 5 years on leaks and 1 year on parts.
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