Best Electric Condensing Tankless Water Heaters for Fast Hot Water
Choosing an electric condensing tankless water heater can deliver continuous hot water with high efficiency while saving space. This guide highlights five top options that balance performance, energy use, and ease of installation for American homes. We compare electric and gas-powered condensing models to help you select a unit that fits your usage, climate, and wiring readiness. A concise buying table is provided to help you compare across key specs at a glance.
| Product | Brand | Type | Max Flow (GPM) | Key Strength |
|---|---|---|---|---|
| Rheem RTEX-24 | Rheem | Electric | Up to 4.4 | High electrical demand with precise temperature control |
| Rinnai RX199iN | Rinnai | Gas Condensing | Up to 11.1 | Indoor/Outdoor versatility with Smart Sense control |
| Rinnai RX180iN | Rinnai | Gas Condensing | Up to 10 | Compact design with Wi‑Fi capable control |
| Rheem RTG-70DVLN-3 | Rheem | Gas Non-Condensing | 7.0 | Reliable performance for 2–3 bathroom homes |
| Rheem RTG-70XLN-3 | Rheem | Gas Non-Condensing Outdoor | 7.0 | Outdoor installation with rugged cabinet |
| Rheem RTGH-95DVLN-3 | Rheem | Gas Condensing | 9.5 | High efficiency with 120 V ignition |
Rheem RTEX-24 Electric Tankless
The Rheem RTEX-24 is a compact electric tankless unit designed for whole-home hot water in moderate demand homes. It uses three 40-amp double-pole breakers and a 240-volt supply, demanding substantial electrical capacity in the home’s panel. Features include a dial-style on/off control, adjustable digital temperature range from 80 to 140 degrees Fahrenheit, and performance influenced by incoming water temperature. This model is best suited for homes with sufficient electrical service and lower simultaneous hot water usage.
NEW Rinnai RX199iN Condensing
The Rinnai RX199iN is a versatile condensing tankless water heater that can be installed indoors or outdoors using Versa Vent. It operates with either propane or natural gas, guided by a Smart Sense gas control system. It’s capable of delivering up to 11.1 GPM, depending on climate and inlet water temperature. The unit features a modern interface, Quick Flush for easy maintenance, and a high energy-efficiency factor (UEF 0.98). Optional ControlR module enables WiFi control when available. Outdoor use requires the RX-OVC vent cap.
Rinnai RX180iN Condensing
The Rinnai RX180iN Condensing model provides up to 10 GPM and is suitable for indoor or outdoor installation with Versa Vent. Its Smart Sense gas control supports propane or natural gas, and it emphasizes a compact form factor with efficient energy use. Like the RX199iN, it includes a Quick Flush feature and a high UEF rating, making it a strong option for households seeking reliable hot water with flexible installation.
Rheem RTG-70DVLN-3
The Rheem RTG-70DVLN-3 is a non-condensing natural gas unit intended for indoor installation. It delivers about 7.0 GPM and uses 160,000 BTUs to provide hot water during peak demand. Its robust cabinet and straightforward mounting make it a practical choice for homeowners needing reliable performance without condenser-managed efficiency. It’s suited for spaces where a sturdy gas line and venting are readily available.
Rheem RTG-70XLN-3 Outdoor
The Rheem RTG-70XLN-3 is an outdoor, non-condensing tankless unit designed for natural gas with 7.0 GPM. Its weather-resistant cabinet is built for exterior installation, and it includes provisions for wall mounting by a qualified installer. This model is ideal for homes with outdoor spaces and buffered venting, providing steady hot water while withstanding environmental exposure.
Rheem RTGH-95DVLN-3
The Rheem RTGH-95DVLN-3 is a high-efficiency condensing gas model rated at 9.5 GPM. It features 199,900 BTU input and includes electric ignition for reliable startup. This indoor unit is designed to optimize energy use while delivering ample hot water for multiple simultaneous demands. Its condensing design helps maximize efficiency even in cooler inlet water conditions.
Buying Guide
When choosing an electric condensing tankless water heater or its closest gas-condensing alternatives, consider the following:
- Flow needs: Estimate the number of fixtures and simultaneous hot-water usage to select a GPM rating that avoids cold-water sandwiching.
- Electrical capacity: For electric models like RTEX-24, verify that your service panel can support the required amperage and that wiring is up to code with a licensed electrician involved.
- Ventilation and installation: Gas condensing units require proper venting and often space advice for indoor or outdoor placement. Check clearances and local code requirements.
- Energy efficiency: Condensing models typically achieve higher UEF ratings. Compare UEF or ENERGY STAR equivalents where available to maximize savings.
- Control features: WiFi-enabled or smart controls can improve monitoring and scheduling, but ensure compatibility with your home network and any ecosystem you prefer.
- Maintenance: Quick Flush or serviceability can simplify flushing and descaling, preserving performance and longevity.
- Fuel availability and cost: Propane/natural gas availability may affect choice and operating costs; electric options can be simpler in some new builds but require wiring upgrades.
- Budget and space: Outdoor units can save indoor space but may require weatherproofing; indoor units may need venting and room in cabinetry or utility areas.
In summary, electric models like the RTEX-24 suit homes with strong electrical service and moderate peak usage, while gas condensing units (Rinnai RX199iN, RX180iN, and Rheem RTGH-95DVLN-3) offer high flow and flexibility for larger households or locations where natural gas or propane is readily available. The outdoor options provide installation flexibility where indoor space is limited. Use the buying guide to weigh installation requirements, efficiency goals, and long-term operating costs.