Compact non-condensing tankless water heaters can free up space while delivering steady hot water on demand. They’re a practical choice for buyers who want simpler installation, strong performance, and lower upfront cost than many condensing models.
Below, we’ve rounded up 10 options that stand out for flow rate, fuel type, and installation style, so you can quickly narrow down the best fit for your home and usage needs.
Best 10 Compact Non Condensing Tankless Water Heaters Picks for 2026
Outdoor Propane Space Saver
Rinnai RE160eP Non-Condensing Propane Tankless Water Heater
- Outdoor non-condensing propane unit
- Up to 6.1 GPM output
- Compact suitcase-sized design
Best For: Outdoor propane homes needing a space-saving whole-home heater
Indoor High-Flow Natural Gas
Rheem RTG 7.0 GPM Non-Condensing Water Heater
- Indoor natural gas tankless unit
- Up to 7.0 GPM output
- Hot-start programming reduces cold bursts
Best For: 2–3 bathroom homes needing high-flow indoor hot water
Quiet Apartment Compact Pick
GASLAND Compact Propane Tankless Water Heater
- Indoor propane model for small spaces
- Up to 4 GPM with stable temp control
- Ultra-quiet compact design
Best For: Apartments, tiny houses, and small homes needing quiet propane heat
Outdoor Natural Gas High Output
Rheem RTG 7.0 GPM Outdoor Non-Condensing Heater
- Outdoor natural gas tankless unit
- Up to 7.0 GPM output
- Freeze protection for outdoor use
Best For: Outdoor natural gas homes needing high output and freeze protection
Compact Whole-Home Propane Pick
180,000 BTU Smart Indoor Heater
- 7.9 GPM for 3 to 5 usage points
- Compact wall-mounted indoor design
- Wi-Fi control with CSA safety protections
Best For: Large families needing a compact propane whole-house heater
Reliable Indoor Gas Option
- Up to 6.5 GPM for household demand
- Compact indoor wall-mounted footprint
- Flexible venting with professional install recommended
Best For: Homes wanting a dependable indoor natural gas tankless unit
High-Flow Smart Indoor Choice
7.9 GPM WiFi Whole-Home Heater
- 7.9 GPM output for 3 to 5 fixtures
- ±1°F temperature stability with smart control
- Compact indoor design with freeze protection
Best For: Busy homes needing stable, app-controlled whole-home hot water
Premium High-Flow Smart Comfort
Rinnai RXP199iN 11.1 GPM with Pump
- Up to 11.1 GPM for whole-home demand
- Built-in Smart-Circ recirculation pump
- Indoor or outdoor install on NG or propane
Best For: Large households wanting high output and recirculation in a compact unit
Compact App-Control Whole-Home
Mizudo 199k BTU Indoor NG 10.3 GPM
- 10.3 GPM supports 5-7 fixtures
- WiFi/app control with remote scheduling
- Sealed direct vent indoor natural gas model
Best For: Large families needing stable whole-home hot water in a compact footprint
Space-Saving Smart Propane
- Compact wall-mounted propane unit
- Zero Cold Water Technology with smart seasonal control
- Built-in booster pump reaches 6.8 GPM
Best For: Smaller households wanting quick hot water and app control in a compact propane unit
Outdoor Propane Space Saver – Rinnai RE160eP Non-Condensing Propane Tankless Water Heater
If you want compact non condensing tankless water heaters for an outdoor propane setup, the Rinnai RE160eP is built around space savings and steady on-demand performance. It delivers up to 6.1 GPM, uses heat only when needed, and includes service reminders plus error codes on the LED screen for easier upkeep.
Best For: Outdoor propane homes that want a compact unit with strong whole-home hot water capacity.
Pros:
- Compact, suitcase-sized design saves space outdoors.
- Up to 6.1 GPM supports multiple fixtures at once.
- Non-condensing design heats only when necessary to conserve energy.
- LED display provides service reminders and error codes.
Cons:
- Outdoor installation limits placement options.
- Professional installation is recommended.
- WiFi control requires a separate Controlr module.
Overall, this is a practical pick if you need a compact propane model that balances space savings with enough output for typical family use. The warranty coverage is also strong, but the outdoor-only setup means it works best where installation conditions are already suitable.
Indoor High-Flow Natural Gas – Rheem RTG 7.0 GPM Non-Condensing Water Heater
Among compact non condensing tankless water heaters, the Rheem RTG Series is a strong indoor option for households that need steady hot water at higher demand. With up to 7.0 GPM, 160,000 BTUs, and hot-start programming, it is designed to handle back-to-back showers and other common peak-use situations.
Best For: 2–3 bathroom homes that want a compact indoor natural gas heater with high flow.
Pros:
- Up to 7.0 GPM suits multi-bathroom homes.
- 160,000 BTUs provide fast, reliable hot water.
- Hot-start programming helps reduce cold water bursts.
- Compact wall-mounted cabinet supports indoor installation.
Cons:
- Indoor installation requires proper venting and installer setup.
- Natural gas only, so it is not for propane homes.
- May be more capacity than small apartments need.
This model makes sense when your main goal is stronger flow without giving up the space-saving benefits of a tankless unit. It is best matched to homes that can use the added output and have a qualified installer handle the setup.
Quiet Apartment Compact Pick – GASLAND Compact Propane Tankless Water Heater
If you are shopping for compact non condensing tankless water heaters for a smaller living space, the GASLAND CG360LP is aimed squarely at apartments, tiny houses, and tight utility areas. It offers up to 4 GPM, stable temperature control, and ultra-quiet operation, all in a compact indoor propane design.
Best For: Apartments, tiny houses, and small homes that need quiet indoor propane hot water.
Pros:
- Compact 18.5″ x 12.2″ x 6.38″ footprint fits tight spaces.
- Up to 4 GPM can serve multiple points of use.
- Precision control keeps temperature within ±0.5°F of the setting.
- Ultra-quiet operation suits apartments and open-plan rooms.
Cons:
- 4 GPM is best for smaller households, not larger ones.
- Indoor propane setup may require more careful installation planning.
- Ceiling mount style may not suit every space.
For buyers prioritizing quiet operation and temperature consistency in a small footprint, this GASLAND model is an appealing fit. It is less about maximum capacity and more about delivering comfortable on-demand hot water in space-constrained homes.
Outdoor Natural Gas High Output – Rheem RTG 7.0 GPM Outdoor Non-Condensing Heater
For buyers comparing compact non condensing tankless water heaters for outdoor installation, the Rheem RTG Outdoor model delivers the same 7.0 GPM, 160,000 BTU performance in a weather-ready cabinet. It is designed for continuous hot water, includes hot-start programming, and adds freeze protection for outdoor use.
Best For: Outdoor natural gas installations that need high flow and freeze protection.
Pros:
- Up to 7.0 GPM supports busy households.
- 160,000 BTUs provide high-output performance.
- Freeze protection helps with outdoor installation.
- Hot-start programming helps reduce cold water bursts.
Cons:
- Outdoor installation narrows placement options.
- Natural gas only.
- Best suited to homes that need the higher flow rating.
This version is the better fit if you want the same output as the indoor Rheem model but prefer an outdoor mount. The added freeze protection makes it a more practical choice in climates where exposure is a concern, though it still needs the right gas setup.
Compact Whole-Home Propane Pick – 180,000 BTU Smart Indoor Heater
If you’re comparing compact non condensing tankless water heaters for a larger household, this Mizudo propane model is built for high-demand indoor use without taking much wall space. It delivers up to 7.9 GPM, supports 3 to 5 usage points, and uses a closed combustion design that draws external air to help preserve indoor air quality.
Best For: Large families wanting a space-saving propane unit with app control and strong whole-home output.
Pros:
- Up to 7.9 GPM and 180,000 BTU for whole-home hot water
- Compact 25″ x 16.3″ x 7.3″ design saves space versus tank heaters
- Wi-Fi/app control for remote monitoring and adjustments
- CSA-certified protection features including freeze prevention and dry-fire safeguard
Cons:
- Non-condensing design may not be the best fit for buyers prioritizing condensing efficiency
- Requires propane and indoor installation setup
- Minimum flow and freezing-weather performance depend on installation and water conditions
This is a practical choice if you want strong flow, smart controls, and a compact footprint in a propane tankless package. Its copper heat exchanger, safety protections, and 5-year heat exchanger warranty add to its appeal for residential whole-house use.
Reliable Indoor Gas Option – RUCS65IN 6.5 GPM Tankless
Among compact non condensing tankless water heaters, the Rinnai RUCS65IN is a straightforward indoor natural gas option built for efficient on-demand hot water. It offers up to 6.5 GPM, a compact wall-mounted form factor, and flexible venting options for homes that need a dependable space-saving setup.
Best For: Buyers who want a trusted indoor natural gas unit with solid flow and professional installation support.
Pros:
- Up to 6.5 GPM supports multiple appliances at once
- Compact indoor design saves space compared with tank heaters
- On-demand heating helps avoid standby energy use
- Flexible venting options expand placement possibilities
Cons:
- Professional installation is recommended
- Not as high-flow as some 7.9 GPM whole-home models
- Indoor natural gas setup may limit compatibility for some homes
This model makes sense if you value established brand support, energy-conscious operation, and a manageable footprint. Its 12-, 5-, and 1-year residential warranty coverage also adds reassurance for long-term use.
High-Flow Smart Indoor Choice – 7.9 GPM WiFi Whole-Home Heater
If you need compact non condensing tankless water heaters for a busy home, this Westinghouse natural gas model focuses on high output in a space-saving indoor design. It delivers up to 7.9 GPM and 180,000 BTU, supports 3 to 5 fixtures simultaneously, and adds Wi-Fi app control for easier day-to-day use.
Best For: Households that want strong flow, smart controls, and stable indoor performance for multiple fixtures.
Pros:
- 7.9 GPM and 180,000 BTU support whole-home use
- ±1°F temperature stability helps reduce hot-cold swings
- Wi-Fi/app and LED panel controls add convenience
- Compact wall-mounted design with freeze protection and copper heat exchanger
Cons:
- Indoor natural gas installation is required
- Non-condensing design may not appeal to shoppers focused on condensing models
- Best suited to homes that can use its 3/4″ NPT connection setup
This unit is a strong fit if you want stable temperature control and smart features without giving up a smaller footprint. Its CSA certification, variable-speed combustion fan, and overheat protection help round out a capable whole-home package.
Premium High-Flow Smart Comfort – Rinnai RXP199iN 11.1 GPM with Pump
If you’re comparing compact non condensing tankless water heaters, this model stands out for buyers who want very high output, flexible install options, and built-in recirculation. It’s a compact gas unit, but it is actually a condensing model, so it makes the most sense if your priority is performance, efficiency, and convenience rather than a true non-condensing design.
Best For: Large households that want a compact, high-capacity tankless unit with built-in recirculation and indoor/outdoor flexibility.
Pros:
- Up to 11.1 GPM and 199,000 BTU output for demanding whole-home use
- Smart-Circ intelligent recirculation helps reduce hot water wait times
- Indoor or outdoor installation with natural gas or propane compatibility
- Very high UEF .98 for an efficient condensing design
Cons:
- Not a non-condensing unit, despite fitting the compact tankless category
- Professional installation is recommended by the manufacturer
- Outdoor setup requires the RX-OVC vent cap
For shoppers who want a space-saving tankless heater with premium convenience features, this Rinnai is a strong long-term option. Just be sure its condensing design and installation requirements match your project before buying.
Compact App-Control Whole-Home – Mizudo 199k BTU Indoor NG 10.3 GPM
This compact non condensing tankless water heater is built for families that want strong whole-home hot water without taking up much space. With 199,000 BTU, 10.3 GPM, and WiFi/app control, it fits buyers looking for an indoor direct-vent gas heater with modern convenience and precise temperature stability.
Best For: Large families that want a compact indoor natural gas tankless heater with app control and stable output.
Pros:
- 10.3 GPM flow rate and support for 5-7 fixtures at once
- Smart WiFi/app control for remote temperature changes and scheduling
- 6-stage modulation keeps temperature within ±1°F
- Sealed direct vent design draws combustion air from outside
Cons:
- Requires a separately purchased 3″x5″ direct vent kit
- Indoor natural gas only, so it is less flexible than dual-fuel models
- Non-condensing design is less efficient than condensing alternatives
For buyers prioritizing compact size, app-based control, and steady hot water delivery, this Mizudo unit covers the essentials well. Its venting requirement and non-condensing design are worth noting, but the overall feature set is strong for a whole-house install.
Space-Saving Smart Propane – APUS 140k BTU 6.8 GPM Wi-Fi
If you’re shopping compact non condensing tankless water heaters for a smaller home or lighter whole-house demand, this APUS propane model is a practical fit. It combines a compact wall-mounted design with Wi-Fi app control, zero cold water technology, and a built-in booster pump for stronger flow.
Best For: Propane users who want a compact, app-controlled tankless heater with fast hot water and moderate whole-home capacity.
Pros:
- Compact 21.26 x 13.58 x 7.09 in. design saves space
- Zero Cold Water Technology and smart seasonal control for comfort
- Built-in booster pump raises flow up to 6.8 GPM
- Wi-Fi app control through Tuya for remote adjustments and monitoring
Cons:
- Lower output than larger whole-house tankless models
- Propane-only, so it is not a natural gas option
- Must be drained if stored in prolonged cold conditions below 41°F
This APUS is a good match if you want a compact unit with modern controls and enough capacity for everyday family use. Its smaller size and simple installation-friendly connection points are appealing, but buyers with heavier hot water demand may want a larger model.
How We Picked the Best Compact Non Condensing Tankless Water Heaters
We focused on models that balance size, output, and real-world usability. Priority went to units with enough BTU capacity and GPM for typical household demand, plus compact cabinets that make sense in tight utility spaces, garages, or indoor mechanical rooms.
We also considered fuel type, installation flexibility, temperature control, and whether the unit is better suited to one or multiple fixtures at once. For compact non-condensing tankless water heaters, the goal is not just saving space—it’s getting the right amount of hot water without overspending on capacity you won’t use.
Quick Comparison
In general, propane models can be easier to place where gas infrastructure is limited, while natural gas units often make sense for larger homes with steady demand. Higher GPM ratings are better for families running showers, laundry, and sinks at the same time. Outdoor-rated models can simplify venting, while indoor models may offer more placement options if venting is already planned.
Key Buying Factors for Compact Non-Condensing Tankless Water Heaters
Flow Rate and Household Demand
Match the unit’s GPM to your actual usage. A smaller household may be fine with a lower-flow model, while larger homes usually need higher output to avoid temperature drops when multiple fixtures run together.
BTU Rating and Recovery
BTU capacity affects how much hot water the heater can produce under load. If you live in a colder climate or need consistent performance at several outlets, choose a model with enough headroom for winter conditions and peak demand.
Fuel Type and Installation Location
Natural gas is common in many whole-home setups, but propane is a strong option for off-grid homes, additions, or spaces without gas service. Also confirm whether the unit is indoor or outdoor rated before you plan venting or mounting.
Controls, Temperature Stability, and Convenience
Digital controls, WiFi features, and tighter temperature regulation can make daily use easier. If comfort matters, look for stable output that minimizes hot-cold swings when taps open and close.
Who Should Buy Which Compact Non Condensing Tankless Water Heaters?
If you want the simplest value-focused setup, choose a compact unit sized for your actual fixture count rather than the biggest model available. Smaller households, cabins, and point-of-use applications can often save money with lower-GPM options. Larger families should prioritize higher BTU and GPM ratings, especially if multiple showers may run at once.
If you care most about flexible placement, compare indoor and outdoor units carefully. If you want easier upgrades and better efficiency, stick with compact non-condensing tankless water heaters that match your fuel source, venting plan, and peak hot-water demand.
