Best Propane Tankless Water Heaters For Cold Climates

Cold incoming water makes a propane tankless water heater work harder: the colder the water entering the unit, the more heat it must add to reach your set temperature. That can reduce the flow you get while several showers or fixtures are running. The options below include outdoor models with listed freeze protection and an indoor model that needs venting, but no built-in feature removes the need to plan for freezing weather, power loss, and proper installation.

Use each unit’s flow rate as a starting point, not a promise of the same output in every climate. Before you buy, check the manufacturer’s sizing guidance against your winter inlet-water temperature, household demand, fuel supply, and installation location.

Quick Comparison

Our Picks: Best Propane Tankless Water Heaters For Cold Climates reviews

1. Rheem RTG Series: A Strong Outdoor Option for Higher Household Demand

The Rheem RTG is an outdoor liquid propane model listed at 7.0 GPM at a 35°F temperature rise. Its product information says it can support two to three simultaneous showers, making it a candidate for a larger household that wants to save indoor space. It has a digital temperature control, wall-mount design, and listed freeze and flame-failure protection.

There is an important detail to confirm before ordering: the product information is inconsistent. The title identifies a liquid propane outdoor model, while parts of the description refer to natural gas or indoor installation. The listed BTU output also differs between sections. Check the exact model number, fuel type, installation requirements, and full technical specifications with Rheem or a qualified installer before purchase.

For a cold-weather installation, the built-in freeze protection is useful, but it should not be treated as a guarantee against freeze damage. Outdoor piping and the unit still need to be installed and protected according to the manufacturer’s instructions. Its listed 7.0 GPM is also tied to a 35°F rise; colder inlet water may mean less usable flow than the headline figure suggests.

Pros:

• Outdoor design avoids the need for indoor venting.
• Listed 7.0 GPM flow rate at a stated 35°F temperature rise.
• Freeze and flame-failure protection are listed.
• Long heat exchanger and parts warranty terms are included in the product information.

Cons:

• Product details conflict on fuel type, installation type, and BTU output, so verify specifications before buying.
• As with other outdoor units, freeze protection does not replace proper cold-weather installation and shutdown planning.

Verdict: Consider the Rheem for a larger home if its specifications are confirmed for your fuel and installation, but resolve the listing’s conflicting details before placing an order.

2. CAMPLUX WA686M: High Listed Capacity and an Indoor Remote

The CAMPLUX WA686M is an outdoor propane heater rated at 199,000 BTU and up to 8.4 GPM. The listing describes it as suitable for several water points at once, but the stated maximum depends on inlet temperature and flow conditions. For a home with cold winter water, compare the manufacturer’s output figures at a temperature rise close to your own needs rather than relying only on the maximum GPM.

Convenience features include an indoor remote with a 32.8-foot cable, temperature adjustment, and listed protections for freezing, overheating, flame failure, and other operating conditions. Its weather-resistant outdoor design can free up indoor space. The product information also specifies 3/4-inch NPT connections, a 120-volt plug, and a one-year limited warranty.

Some owners describe straightforward setup and dependable hot water in everyday use. That experience is encouraging, but it does not replace professional installation or confirm performance in every climate. The unit’s freeze protection needs power to operate, so plan how you will protect or drain the heater and exposed water lines if the power goes out or the home will be vacant.

Pros:

• High listed output of 199,000 BTU and up to 8.4 GPM.
• Indoor remote allows temperature adjustment from inside the home.
• Outdoor installation saves indoor space.
• Multiple safety protections and a CSA certification are listed.

Cons:

• The one-year limited warranty is shorter than the listed coverage for several competing models.
• Maximum flow may not reflect output with very cold incoming water.

Verdict: The CAMPLUX is worth considering if you want a high-capacity outdoor unit and an indoor control, provided its cold-water output and warranty suit your needs.

3. Westinghouse 8.1 GPM: A High-Capacity Outdoor Model with a Wired Controller

This Westinghouse outdoor propane model is listed at 180,000 BTU and up to 8.1 GPM. The manufacturer describes it as suitable for several fixtures running at once and specifies an adjustable temperature range of 95°F to 158°F. A wired digital controller and self-modulating gas and water controls are intended to help maintain a steady outlet temperature as demand changes.

For cold-climate use, the listing’s freeze protection is a useful feature, and the outdoor format keeps the unit out of the home. The heater requires 120-volt AC power and standard 3/4-inch NPT residential plumbing connections, according to the product information. It also lists a two-year limited warranty for the unit and an extended five-year warranty for the heat exchanger.

Owners have described reliable temperature control and straightforward connections in their own installations. Still, the listed 8.1 GPM should not be read as guaranteed winter flow. If your incoming water is very cold or several showers run together, ask an installer to check whether the unit can meet your required temperature rise and demand.

Pros:

• Listed 180,000 BTU output and up to 8.1 GPM.
• Freeze protection and a wired digital controller are included.
• Temperature range extends from 95°F to 158°F.
• Heat exchanger warranty is listed at five years.

Cons:

• Requires a 120-volt power supply, including for electronic controls and freeze protection.
• Cold incoming water can reduce the flow available at the desired temperature.

Verdict: This Westinghouse is a compelling option for households seeking high listed capacity and a wired controller, as long as a professional confirms its output for your winter conditions.

4. APUS 5.43 GPM: An Indoor Choice for Moderate Household Demand

The APUS is an indoor propane model rated at 120,000 BTU and up to 5.43 GPM. Its product information presents it as an option for a household using a couple of showers and another fixture, though actual performance depends on the temperature rise and combined flow. A listed low-flow start of 0.66 GPM may also help it respond to smaller draws.

The compact wall-mounted design includes an LED touchscreen, temperature adjustment from 95°F to 149°F, and a vent pipe in the included components. Its freeze protection is listed as activating near 41°F. The manufacturer also advises fully draining the unit below that temperature or during extended non-use. That makes the installation location and your ability to drain the system important parts of the buying decision.

The APUS differs from the other four picks because it is designed for indoor installation, so venting and clearances must be handled correctly. Its smaller listed capacity may suit a modest home, but it is less suited to heavy, simultaneous demand than the higher-output outdoor models. Confirm venting, fuel-line sizing, and cold-weather procedures with a qualified installer.

Pros:

• Indoor design avoids placing the heater cabinet outdoors.
• Listed 120,000 BTU output and up to 5.43 GPM.
• Freeze protection and automatic shutoff features are specified.
• Vent pipe and installation components are listed as included.

Cons:

• Lower listed capacity than the other models in this group.
• Requires correct indoor venting and draining when freezing conditions or extended non-use call for it.

Verdict: Choose the APUS if you need an indoor propane unit for moderate demand and can meet its venting and freeze-management requirements.

5. Rinnai V53DeP: A Compact Outdoor Heater from an Established Brand

The Rinnai V53DeP is a compact outdoor propane heater with a listed 5.3 GPM flow rate. It is designed to save indoor space and heat water on demand, while its scale-detection feature is intended to help with maintenance. The smaller capacity makes it a better fit for a modest household or lower simultaneous demand than for a large home running multiple showers and appliances together.

Some owners describe successful use in cold conditions, including an outdoor installation, but that does not establish a guaranteed operating limit or mean the unit can safely withstand every freeze. The product information does not clearly list built-in freeze protection for this model. Ask Rinnai or your installer what protection is required for your location and how to drain or protect the unit during a freeze or power outage.

Warranty information in the product details is not fully consistent: it includes different summaries for the heat exchanger and labor coverage. The listed residential terms refer to registration within 90 days and say labor coverage changes if the product is not registered. Confirm the exact warranty for the specific model and installation before purchase.

Pros:

• Compact outdoor design saves indoor floor space.
• Listed 5.3 GPM output may suit smaller households.
• Scale detection is included in the product description.
• Rinnai lists extended warranty terms, subject to conditions and registration.

Cons:

• Lower listed capacity than the higher-output alternatives.
• Freeze protection is not clearly specified in the product information, and warranty summaries differ.

Verdict: The Rinnai may suit a smaller household seeking a compact outdoor unit, but confirm cold-weather protection and the applicable warranty before choosing it for a freezing climate.

How to Choose a Propane Tankless Water Heater for a Cold Climate

Size the heater for your winter temperature rise

Start with the temperature of your incoming water during the coldest part of the year and the hot-water temperature you need. The difference is the temperature rise the heater must provide. A larger rise puts more demand on the unit, so its maximum flow rate may not be available at your target temperature. Ask the manufacturer or installer for flow data at a temperature rise that matches your home rather than comparing maximum GPM alone.

Estimate how many fixtures may run together

Think about your busiest use, such as two showers running while a sink or dishwasher is in use. Add the expected flow from those fixtures and compare it with the heater’s output at your required temperature rise. If your household often uses several fixtures at once, a higher-capacity model may be a better starting point, but the cold-water performance still needs to be checked.

Plan for freeze protection and power interruptions

Many models use powered freeze protection, but that protection may not work during an outage. Outdoor units also have exposed connections and piping that need careful placement and protection. Follow the exact installation and shutdown instructions for the selected model. If the home may be left unheated or without power, ask your installer how to drain or otherwise protect the heater and water lines.

Choose indoor or outdoor installation based on your home

An outdoor unit can avoid indoor venting and preserve interior space, but it is exposed to weather and may need more careful freeze planning. An indoor unit avoids an outdoor cabinet but requires approved venting, clearances, and a suitable location. Confirm local code requirements and the manufacturer’s instructions before deciding where the heater can go.

Confirm propane supply and electrical needs

Tankless heaters need a propane supply that can meet the appliance’s demand. Have a qualified professional check the gas line, connections, and propane setup against the unit’s requirements. Also check whether the heater needs 120-volt power for ignition, controls, or freeze protection. The models in this guide list electrical requirements, so do not assume a tankless unit works without household power.

Check warranty details and service needs

Compare the warranty on the heat exchanger, parts, and labor, and read any registration conditions. Regular maintenance and water quality can also affect long-term operation. Ask about descaling or flushing requirements for your water conditions, and confirm that qualified service is available for the model you choose.

Frequently Asked Questions

Does a propane tankless water heater work well in a cold climate?

It can, if it is correctly sized for the winter temperature rise and installed according to the manufacturer’s instructions. Cold incoming water can reduce the flow available at your target temperature, so check performance figures for your conditions before buying.

Will freeze protection keep an outdoor unit safe in a power outage?

Do not assume so. Powered freeze protection may not operate without electricity. Ask the manufacturer or installer how to protect or drain the unit and exposed piping during outages, severe cold, or extended time away.

Is a higher GPM rating always better?

No. A listed maximum GPM does not show how much hot water the unit can deliver at your winter temperature rise. Compare output at the temperature rise and simultaneous fixture demand you expect in your home.

Should I choose an indoor or outdoor propane heater?

That depends on your available space, venting options, local rules, and freeze exposure. Outdoor models can avoid indoor venting, while indoor models need the correct venting and installation clearances. Either type requires following the manufacturer’s cold-weather instructions.

Do these heaters need electricity?

Several models in this guide list a 120-volt power requirement. Electricity may operate controls, ignition, or freeze protection. Verify the exact model’s electrical needs and plan for what happens if power is interrupted.

Can I install a propane tankless water heater myself?

Professional installation is the safer choice. The work involves propane connections, water plumbing, and—on indoor models—venting. A qualified installer can also check gas supply, local code requirements, and cold-weather protection.

Final Recommendation

For a household that needs higher listed capacity, the Westinghouse and CAMPLUX are worth comparing, but their maximum flow claims should be checked against your winter inlet temperature. The APUS is a more modest-capacity indoor option, while the Rinnai may fit a smaller household if its cold-weather protection is suitable. The Rheem could be a strong outdoor candidate, but its product information contains conflicting specifications that should be resolved first. In every case, choose based on verified cold-water output, proper propane supply, and a clear plan for freezing weather and power loss.