A tankless heater can free up closet space in a condo, but a compact unit is not automatically an easy fit. Electrical capacity, gas venting, and building rules matter as much as the heater’s dimensions.
These 10 options span smaller electric units, higher-output models, and one indoor natural-gas choice. Use the guide below to narrow the field before asking a qualified installer what your condo can support.
Best 10 Tankless Water Heaters for Condos Picks for 2026
Best Smart Controls
Westinghouse 14kW WiFi Electric Heater
- WiFi, voice control, and temperature memory
- 3.4 GPM at the stated 62°F-to-105°F test conditions
- Needs a dedicated 240V, 60A circuit
Best For: Condos with adequate electrical capacity and a preference for smart controls
Best Natural Gas Option
- Listed 4.42 GPM and 95,000 BTU output
- LED touchscreen with 95°F–140°F settings
- Needs permitted gas, venting, and 120V power
Best For: Condos approved for an indoor natural-gas installation
Best Precise Temperature Control
- Specified ±1°F temperature control
- Up to 3.38 GPM; compact wall-mount design
- Requires 60A circuit and at least 150A panel capacity
Best For: Electrically compatible condos prioritizing stable temperature
Best Higher-Output Electric
- 18kW output; listed flow up to 4.4 GPM
- Self-modulating with digital temperature control
- Verify electrical capacity and 3/4-inch NPT plumbing
Best For: Condos equipped for a higher-output 240V electric heater
Best for Wi-Fi Control
WINTEMP WN18 18kW Electric Tankless Heater
- Remote Wi-Fi temperature control
- Self-modulating, up to 4.3 GPM
- Needs two 40A double-pole breakers
Best For: Condos with suitable electrical service and a preference for remote controls
Best Compact 13kW Option
- Compact 8.25-by-12.62-inch face
- 1°F digital temperature adjustments
- Confirm conflicting listed flow rates
Best For: Smaller hot-water loads where wall space is tight
Best Slim 18kW Design
- Slim 3.18-inch wall profile
- Advertised maximum of 4.9 GPM
- Requires two 40A double-pole breakers
Best For: Condos prioritizing a shallow cabinet and multiple water-use points
For Higher Demand
Rheem RTEX-24 24kW Electric Tankless Heater
- Up to 5.9 GPM listed flow
- No venting; 3.5-inch depth
- Needs three 40-amp breakers
Best For: Condos with higher demand and sufficient electrical capacity
For One or Two Fixtures
14kW 240V Electric Tankless Heater
- Listed 3.3 GPM flow
- Under-sink or wall installation
- Requires one 60-amp breaker
Best For: One or two usage points with a suitable 240V circuit
For Lower Demand
Rheem RTEX-11 11kW Electric Tankless Heater
- Up to 2.68 GPM listed flow
- Compact, vent-free wall mount
- Needs one 50-amp breaker
Best For: Lower-demand setups with compatible electrical service
Best Smart Controls – Westinghouse 14kW WiFi Electric Heater
Among tankless water heaters for condos, this compact Westinghouse model stands out if you want app and voice control without giving up floor space. Its 14kW output is rated at 3.4 GPM when raising 62°F inlet water to 105°F, so actual flow depends on your incoming water temperature.
Best For: Condos with suitable electrical capacity where convenient temperature control and a compact wall-mounted unit matter most.
Pros:
- WiFi app control, Alexa and Google Home compatibility, and temperature memory after an outage.
- Measures just 12.59 inches high by 9.56 inches wide by 3.28 inches deep.
- ETL certified; removable inlet filter and rotor simplify periodic cleaning.
Cons:
- Requires a dedicated 240V, 60A double-pole breaker and 6 AWG wiring.
- Its stated 3.4 GPM performance assumes relatively warm 62°F inlet water.
Check your condo’s electrical capacity and installation rules before buying. If those work, the smart controls and small footprint make this a practical choice for managing hot water in a tight space.
Best Natural Gas Option – APUS 95,000 BTU Indoor Heater
For shoppers comparing tankless water heaters for condos with an existing natural-gas setup, this APUS unit offers a listed 4.42 GPM flow rate and 95,000 BTU heating capacity. Its slim wall-mounted body may help in a tight utility area, but gas and venting requirements make installation approval especially important.
Best For: Condos where natural gas and an appropriate indoor venting arrangement are already permitted.
Pros:
- Listed 4.42 GPM flow rate and 0.66 GPM minimum activation flow.
- LED touchscreen adjusts the temperature from 95°F to 140°F.
- Compact 20.55-by-13.27-by-5.91-inch design; vent pipe is included.
Cons:
- Requires a suitable natural-gas supply, venting arrangement, and 120V power.
- Gas installation may not be allowed under a condo building’s rules.
This is the fuel-specific pick when electrical heater capacity is a concern. Confirm the building’s gas and venting permissions and have the installation requirements reviewed before counting on its stated multi-fixture performance.
Best Precise Temperature Control – ORBEK 14kW Electric Heater
The ORBEK is a compact contender among tankless water heaters for condos when steady shower temperature is a priority. It lists up to 3.38 GPM and uses an LED display for setting temperatures from 86°F to 140°F, but its electrical requirements need checking first.
Best For: Condos with a compatible electrical panel whose owners want a small electric unit with digital temperature adjustment.
Pros:
- Built-in control chip is specified to maintain temperature within 1°F.
- Measures 14.2 inches high by 9.5 inches wide by 3.1 inches deep.
- ETL certified, with listed leakage, over-temperature, and dry-heating protections.
Cons:
- Requires a 240V, 60A two-pole breaker, 6 AWG wiring, and a panel with at least 150A total capacity.
- Its listed 3.38 GPM is a maximum; available flow will vary with the required temperature rise.
ORBEK’s temperature controls and narrow profile suit a space-conscious installation, provided an electrician confirms the condo can accommodate the dedicated circuit and panel requirement.
Best Higher-Output Electric – Rheem RTEX-18 18kW Heater
If you’re comparing tankless water heaters for condos and need more listed electric output, the Rheem RTEX-18 offers 18kW and a flow rating of up to 4.4 GPM. Its self-modulating power control adjusts to demand, though actual hot-water flow depends on the temperature rise needed.
Best For: Condos with electrical capacity for an 18kW heater and demand that justifies a higher-output electric model.
Pros:
- Up to 4.4 GPM listed flow rate.
- Digital thermostatic control with a display and stated 1°F accuracy.
- Self-modulating operation and field-serviceable copper heating elements.
Cons:
- Its 18kW, 240V load calls for careful review of the condo’s electrical capacity and installation requirements.
- Uses bottom 3/4-inch NPT water connections, which may require plumbing changes when replacing a different unit.
This Rheem makes sense when the smaller 14kW options look limiting and the electrical setup supports the step up. Have an installer verify circuit and plumbing compatibility before choosing it for a condo.
Best for Wi-Fi Control – WINTEMP WN18 18kW Electric Tankless Heater
Among tankless water heaters for condos, the WINTEMP WN18 stands out if you want remote temperature control and have room in your electrical panel for an 18kW unit. Its wall-mounted body measures 11.1 by 19.2 by 4 inches.
Best For: Condo owners who want Wi-Fi temperature adjustments and have an electrician-confirmed installation path.
Pros:
- Wi-Fi control lets you adjust the temperature remotely.
- Self-modulating operation adjusts power to water flow and incoming temperature.
- ETL certified, with leakage, overheat, and dry-fire protection.
Cons:
- Requires two 40A double-pole breakers and two runs of 8/2 AWG wiring; the manufacturer recommends 150A household service.
- The stated 4.3 GPM maximum will vary with incoming water temperature and the temperature rise needed.
This is a strong choice when connected controls matter, but verify electrical capacity and expected shower performance before ordering.
Best Compact 13kW Option – Rheem RTEX-13 Tankless Heater
If you’re comparing tankless water heaters for condos with limited wall space, the Rheem RTEX-13 is an 8.25-by-12.62-inch option with a digital temperature display. Its 13kW rating makes it worth evaluating for a more modest hot-water load than the 18kW models here.
Best For: Condos with a suitable 240V electrical setup and a focused hot-water demand.
Pros:
- External temperature controls adjust in 1°F increments.
- Self-modulating power control responds to demand.
- Two copper immersion heating elements are field-serviceable; 1/2-inch NPT adapters are included.
Cons:
- Its listed 54A draw still calls for careful electrical planning.
- The notes give conflicting flow figures: up to 3.17 GPM in the bullets and 4.8 GPM in the details, so confirm performance before purchase.
The RTEX-13 favors straightforward controls and a small footprint; match its verified flow at your required temperature rise to the fixtures you intend to run.
Best Slim 18kW Design – NOVIEEX DS-18 Tankless Heater
For shoppers weighing tankless water heaters for condos, the NOVIEEX DS-18 pairs an 18kW rating with a slim, 3.18-inch-deep wall-mounted body. The manufacturer lists up to 4.9 GPM and positions it for two to three water-use points.
Best For: Condos needing a shallow installation profile and planning to use more than one fixture, subject to electrical and flow checks.
Pros:
- Measures 11.14 by 15.86 by 3.18 inches.
- LED display and 1°F temperature adjustments across a stated 77°F–140°F range.
- Adaptive heating adjusts to incoming-water changes; listed protections include over-temperature cutoff and leakage protection.
Cons:
- Requires two 40A double-pole breakers and two sets of 8 AWG wiring with a ground wire.
- The advertised 4.9 GPM is a maximum, not a guaranteed flow at every incoming-water temperature.
Its shallow cabinet may help in a crowded utility area, but have an electrician confirm the required circuits and check how much hot water it can deliver at your local temperature rise.
For Higher Demand – Rheem RTEX-24 24kW Electric Tankless Heater
Among tankless water heaters for condos, the Rheem RTEX-24 is the higher-output choice here: its 24kW rating and listed flow of up to 5.9 GPM make it worth considering when more than one fixture may need hot water. Its slim, wall-mounted body saves floor space and needs no venting.
Best For: Condos with higher hot-water demand and an electrical setup that can accommodate the required circuits.
Pros:
- Listed output of up to 5.9 GPM for multiple-fixture use.
- Digital temperature settings from 80°F to 140°F in 1°F increments.
- Compact, 3.5-inch-deep design requires no venting.
Cons:
- Requires three 40-amp double-pole breakers, three sets of #8 AWG copper conductors, and a recommended minimum 200-amp household service panel.
- Actual hot-water performance depends on proper sizing and installation.
Check available panel capacity with a qualified installer before choosing this model; its higher output comes with the most demanding wiring requirements of these three options.
For One or Two Fixtures – 14kW 240V Electric Tankless Heater
If you’re comparing tankless water heaters for condos with limited installation space, this 14kW model offers a compact under-sink or wall-mount option. Its listed 3.3 GPM flow and stated support for one or two simultaneous usage points put it between the two Rheem models in rated power.
Best For: A kitchen-and-bathroom setup where the hot-water demand fits a 14kW unit and a 60-amp circuit is available.
Pros:
- Compact design can be installed under a sink or on a wall.
- LED controls adjust from 86°F to 131°F in 1°F increments.
- Includes leakage and overheating protection plus automatic shutoff.
Cons:
- Requires a dedicated 60-amp breaker and 240V power.
- Its stated one-to-two-point use may not suit heavier simultaneous demand.
Confirm the available circuit and expected fixture use before buying. The compact format is appealing, but matching the heater to your demand matters more than its small footprint.
For Lower Demand – Rheem RTEX-11 11kW Electric Tankless Heater
For shoppers considering tankless water heaters for condos with more modest hot-water needs, the Rheem RTEX-11 is the lowest-power option in this group. It offers up to 2.68 GPM in a compact, wall-mounted design that does not require venting.
Best For: Lower-demand condo installations where the available electrical service meets this model’s requirements.
Pros:
- Requires one 50-amp double-pole breaker rather than multiple breaker circuits.
- Small 8.25-by-12.63-inch listed face dimensions save wall space.
- Digital temperature settings run from 80°F to 140°F in 1°F increments.
Cons:
- Listed flow of up to 2.68 GPM offers less headroom for simultaneous use than the other two models.
- Requires #8 AWG copper conductors and a recommended minimum 100-amp household service panel.
This is a practical smaller-unit candidate, but don’t assume its multi-fixture description guarantees adequate flow for every combination of taps. Size it to your actual demand and verify the wiring before installation.
How We Picked the Best Tankless Water Heaters for Condos
We considered the listed power ratings, fuel types, and stated flow rates across these 10 models, then focused on the questions condo buyers need to resolve: whether the building permits the installation, whether existing utilities can support it, and how much hot water the household needs at once. A product’s advertised maximum flow is not a guarantee of the same performance in every home; incoming water temperature and the temperature you select affect usable flow. Verify current specifications and installation requirements before buying.
Quick Comparison: Tankless Water Heaters for Condos
For one fixture or lighter demand: Start with the Rheem 11kW and RTEX-13, then compare the 14kW options from Westinghouse, ORBEK, and the listed sink-and-shower model. For potentially higher simultaneous demand: Compare the Rheem 18kW, the listed 18kW WiFi model, NOVIEEX 18kW, and Rheem RTEX-24 24kW—provided your electrical service can accommodate them. For an approved gas installation: APUS is the natural-gas option in this lineup. These are starting points, not fixture-count guarantees.
Key Buying Factors for Tankless Water Heaters for Condos
Building Approval and Installation Location
Check condo association rules and local permit requirements first. Ask whether a heater can be installed in the intended location and whether changes to wiring, plumbing, gas piping, or venting are allowed. A small cabinet footprint does not eliminate clearance and access requirements.
Electrical Service or Gas Infrastructure
Every electric model listed operates at 240V, but wattage alone does not tell you whether it will fit your panel. Have a licensed electrician check the required circuits, breaker sizes, wire sizing, and available service capacity using the manufacturer’s instructions. The APUS gas model instead requires a suitable natural-gas supply and code-compliant indoor venting; do not assume an existing condo vent or shared shaft can be used.
Real-World Hot-Water Demand
Add up the flow rates of fixtures you expect to run together, then compare that demand with manufacturer performance data at the temperature rise your location requires. Colder inlet water means a heater must do more work to reach your chosen outlet temperature, reducing the flow it can deliver. A unit that handles one shower comfortably may struggle when someone opens a sink at the same time.
Who Should Buy Which Tankless Water Heaters for Condos?
Single occupant or one-at-a-time use: Investigate an 11kW, 13kW, or 14kW electric model if its published performance matches your inlet temperature and shower flow. Households wanting more overlap: Consider an 18kW or 24kW model only after confirming both its hot-water performance and the electrical work required. Condos already equipped for an approved individual gas appliance: Compare the APUS against the building’s fuel and venting rules. If your panel, gas setup, or association rules cannot support the installation, keeping or replacing a conventional tank may be the more practical choice.
