Propane Tankless Water Heater

Propane Tankless Water Heater

This makes the propane tankless water heater the go-to hot water solution for off-grid homes, rural properties, cabins, RVs, and any location beyond the natural gas line. By burning propane on demand, these units provide continuous hot water for showers, sinks, and appliances without the standby energy loss of a tank, without a natural gas connection, and in indoor, outdoor, and portable configurations to match the installation.

A propane tankless water heater (also called a propane on-demand or propane instant water heater) is available in whole-home indoor and outdoor models, compact portable and RV units, and off-grid configurations that operate without electricity. They range in output from small point-of-use units through whole-house models rated for multiple simultaneous fixtures, measured in gallons per minute (GPM) of hot water delivery. Because propane stores in a standard refillable tank, a tankless propane water heater brings on-demand hot water anywhere: no utility gas line, no waiting for a tank to reheat, and no running out of hot water mid-shower.

The Trade Table carries propane tankless water heaters from Eccotemp, Marey, PrecisionTemp, and other leading brands, covering indoor whole-home units, outdoor models, and portable and off-grid configurations that deliver endless propane-fueled hot water for homes, cabins, RVs, and remote properties.

Propane Tankless Water Heater | On-Demand LP Hot Water for Home, Cabin, RV & Off-Grid

A propane tankless water heater heats water on demand by firing a propane burner the moment a hot water tap opens. Cold water flows through a heat exchanger, the burner heats it instantly, and hot water flows continuously for as long as the tap runs. When the tap closes, the burner shuts off, so there's no energy wasted keeping a tank of water hot around the clock. This on-demand operation, combined with propane fuel, makes the unit ideal for anywhere without natural gas: the propane comes from a standard refillable tank, so the heater works off the utility grid entirely for gas, and many models also run without electricity for true off-grid capability.

Indoor propane tankless water heaters install inside the home and vent combustion gases outside through a dedicated vent, serving as the whole-home hot water source for houses and cabins on propane. Outdoor propane tankless water heaters mount on an exterior wall and vent directly to the open air, eliminating indoor venting requirements, popular for cabins, additions, and warmer climates where freeze protection is manageable. Both indoor and outdoor whole-home models deliver the GPM output to run multiple fixtures, sized to the home's simultaneous hot water demand.

Portable propane tankless water heaters are compact, lightweight units that connect to a propane tank and a water source for hot water anywhere: camping, RV use, outdoor showers, cabins, and job sites. Many portable models are battery-ignition (running without any electrical hookup), making them fully self-contained for off-grid and mobile use. These units bring hot showers and washing water to places with no plumbing infrastructure at all, needing only propane, a water supply, and in some cases a couple of batteries for ignition. Compact point-of-use propane instant water heaters serve a single fixture where a full-size unit isn't needed.

Off-grid propane tankless water heaters are designed to operate without grid electricity, using battery ignition or hydro-powered ignition (powered by the water flow itself) rather than a 120V connection, so they deliver hot water on solar, battery, and propane-based off-grid systems. This is the key advantage of propane for off-grid living: unlike electric tankless water heaters that draw enormous electrical loads a solar/battery system struggles to supply, a propane on-demand water heater does its heating with propane and needs little or no electricity, making it the practical off-grid hot water choice.

Propane tankless water heaters are sized by GPM (gallons per minute) and by the temperature rise they can achieve at a given flow rate. A small point-of-use or portable unit might deliver 1.5 to 3 GPM, suitable for a single shower or sink, while whole-home models deliver 5 to 10 GPM to run multiple fixtures at once. Sizing depends on the number of simultaneous hot water fixtures and the incoming water temperature: colder climates require more output for the same flow because the unit works harder to raise the water temperature. The Trade Table helps size the right propane tankless water heater to the application and climate.

Propane Tankless Water Heater Options

• Indoor whole-home propane tankless water heaters
• Outdoor wall-mount propane tankless water heaters
• Portable propane tankless water heaters for RV and camping
• Off-grid propane tankless water heaters with battery or hydro ignition
• Point-of-use propane instant water heaters for single fixtures
• Whole-house models delivering 5 to 10 GPM for multiple fixtures
• Battery-ignition models that run without electricity
• Small propane tankless water heaters for compact spaces
• Eccotemp, Marey, and PrecisionTemp propane tankless units
• RV and mobile propane on-demand water heaters
• Freeze-protected models for cold-climate installation
• Liquid propane (LP) configurations for off-grid and rural use

Benefits of Propane Tankless Water Heaters

• Endless on-demand hot water, never runs out mid-shower
• Runs on liquid propane where natural gas isn't available
• No standby energy loss from keeping a tank hot
• Off-grid capable, many models run without electricity
• Compact, space-saving design versus tank water heaters
• Indoor, outdoor, and portable configurations
• Ideal for cabins, RVs, rural, and remote properties
• Propane fuels from a standard refillable tank
• Instant hot water heating as water flows
• Lower operating cost than keeping a tank heated 24/7
• Battery and hydro ignition options for no-electricity operation
• Long service life compared to tank water heaters

Common Uses for Propane Tankless Water Heaters

• Off-grid homes and cabins without natural gas or grid power
• Rural properties beyond the natural gas line
• RV, van, and mobile hot water
• Outdoor showers and camp washing stations
• Whole-home hot water on propane
• Additions and outbuildings needing hot water
• Cabins and vacation properties
• Hunting camps and remote job sites
• Replacing a propane tank water heater with on-demand
• Solar and battery off-grid systems needing low-electricity hot water
• Point-of-use hot water for a single remote fixture
• Warm-climate outdoor installations

Why Buy Propane Tankless Water Heaters from The Trade Table?

The Trade Table helps customers select the right propane tankless water heater based on installation type (indoor, outdoor, or portable), hot water demand (GPM needed for the number of simultaneous fixtures), off-grid requirements (battery or hydro ignition for no-electricity operation), climate (temperature rise needed and freeze protection), and application (whole-home, cabin, RV, or point-of-use). Our team provides guidance on sizing the unit's GPM to the fixtures and incoming water temperature, choosing between indoor and outdoor venting, selecting off-grid-capable ignition for solar and battery systems, and matching the heater to cabin, RV, and rural installations. We carry propane tankless water heaters from Eccotemp and other leading brands, part of our full tankless water heater lineup that also includes electric and natural gas options for other fuel needs.

Propane Tankless Water Heater FAQs

How much propane does a tankless water heater use?

A propane tankless water heater uses propane only when you're actually running hot water, rather than keeping a tank hot around the clock, so it's generally more propane-efficient than a propane tank water heater. Actual consumption depends on the unit's BTU rating, how much hot water you use, and the temperature rise required (colder incoming water uses more propane to reach the target temperature). As a rough guide, a typical whole-home propane tankless unit consumes propane at its rated BTU input only while firing, so a household using a moderate amount of hot water goes through far less propane than one continuously heating a standby tank. For off-grid and rural users monitoring a propane supply, the on-demand efficiency means a tank lasts longer between refills. The Trade Table can help estimate propane consumption for a specific unit and usage pattern.

What size propane tankless water heater do I need?

Sizing a propane tankless water heater depends on the flow rate you need (measured in gallons per minute, GPM) and your climate. First, add up the GPM of the fixtures you want to run simultaneously: a shower is roughly 2 to 2.5 GPM, a sink about 1 to 1.5 GPM. Then account for temperature rise: in colder climates, incoming water is colder, so the unit needs more capacity to reach shower temperature at the same flow. A single-shower cabin or RV might need only 1.5 to 3 GPM, while a whole home running multiple fixtures at once needs 5 to 10 GPM. Point-of-use and portable units cover single fixtures; whole-home models handle multiple. The Trade Table helps calculate the right GPM for your fixtures and climate.

How does a propane tankless water heater work?

A propane tankless water heater works by firing a propane burner the instant a hot water tap opens. Cold water flows through a heat exchanger, the propane burner heats it on the way through, and hot water flows continuously for as long as the tap runs. When you close the tap, the burner shuts off, so no energy is spent keeping water hot when you're not using it. The unit runs on liquid propane from a refillable tank, and depending on the model, ignition is handled by battery, a hydro-powered igniter driven by the water flow, or a standard electrical connection. This on-demand operation is what gives a propane tankless water heater its endless hot water and its efficiency advantage over a standby tank heater.

How does a propane tankless water heater work off-grid?

Propane tankless water heaters are well-suited to off-grid living because they do their heating with propane rather than electricity. Off-grid models use battery ignition (a couple of D-cell batteries spark the burner) or hydro-powered ignition (the water flow itself generates the spark), so they need no 120V grid connection at all. This is a major advantage over electric tankless water heaters, which draw very high electrical loads (often 100+ amps) that a solar and battery system can't practically supply. With a propane tankless unit, your off-grid system only needs to supply propane and water: the heating energy comes from the propane, not your batteries, so you get endless hot water without draining your off-grid power.

What's the difference between a propane and natural gas tankless water heater?

Both work identically, heating water on demand with a gas burner, but they use different fuels and are configured for those fuels. A propane (LP) tankless water heater runs on liquid propane from a refillable tank, ideal where there's no natural gas line: off-grid, rural, cabins, and RVs. A natural gas tankless water heater connects to a municipal natural gas line for unlimited fuel supply, ideal for homes with existing gas service. The units have different orifices and gas valve settings calibrated for each fuel's pressure and energy content, so they aren't interchangeable without a conversion kit. Choose propane if you don't have a natural gas line; choose natural gas if you do. Some models offer both configurations or field-convertible kits.

Can a propane tankless water heater be used in an RV?

Yes, portable and RV-specific propane tankless water heaters are a popular category, connecting to the RV's propane supply (or a portable propane tank) and water source to deliver on-demand hot showers and washing water. Many RV and portable models use battery ignition so they run without shore power, making them ideal for boondocking and off-grid camping. They're compact, mount inside an RV or set up portably at a campsite, and eliminate the small tank capacity of traditional RV water heaters by providing continuous hot water. Look for models designed for mobile or portable use with the appropriate GPM for RV fixtures and freeze protection if you camp in cold weather.

Do propane tankless water heaters need electricity?

It depends on the model. Many propane tankless water heaters, especially portable, RV, and off-grid models, use battery ignition or hydro-powered ignition and require no electrical connection at all, running entirely on propane and water. This is a key reason propane tankless heaters are favored for off-grid and mobile use. Other whole-home propane tankless models, particularly some indoor units with powered venting or electronic controls, do require a standard 120V connection for the fan and controls (though they still use propane for heating, so the electrical draw is minimal compared to electric tankless units). If you need a no-electricity unit for off-grid use, choose a model specifically designed with battery or hydro ignition and no electrical requirement.

Can you install a propane tankless water heater outdoors?

Yes, outdoor propane tankless water heaters are designed to mount on an exterior wall and vent combustion directly to the open air, eliminating the indoor venting that indoor models require. This simplifies installation and saves indoor space, making outdoor units popular for cabins, additions, and warmer climates. The main consideration is freeze protection: in climates where temperatures drop below freezing, an outdoor unit needs freeze-protection features (many include them) and proper precautions to prevent the water inside from freezing and damaging the unit. In warm climates, outdoor installation is straightforward. Always confirm the model is rated for outdoor installation and has appropriate freeze protection for your climate before installing outside.