Answering the search for dependable gas direct vent water heaters, this guide highlights five solid options suited to different households. These units provide on-demand hot water with venting designed for indoor or outdoor installation and vary in flow and BTU capacity to match family size and usage. Ideal buyers include small to mid-size homes, larger households needing higher GPM, and installers seeking direct vent efficiency. Below, compare each model’s strengths, best uses, and limitations to help you choose wisely.
Product Quick Reference
- Rheem RTG-70DVLN-3 High Efficiency: Indoor tankless unit, up to 7.0 GPM, 160,000 BTU.
- MIZUDO 180,000 BTU: Indoor tankless, up to 7.9 GPM, WiFi control, CSA certified.
- ORBEK Natural Gas Tankless: Outdoor unit, up to 5.1 GPM, 120,000 BTU, CSA certified.
- A. O. Smith Tankless Water Heater: Indoor, up to 8.0 GPM, 190,000 BTU, X3 scale tech.
- EXCEL Vent-Free Tankless: Propane, 1.6 GPM startup, vent-free design.
Rheem RTG-70DVLN-3 High Efficiency Indoor Tankless Gas Water Heater
This indoor tankless heater delivers up to 7.0 GPM at 160,000 BTUs for compact homes with multiple simultaneous hot water needs, such as showers and laundry. Best for small to mid-size homes with moderate hot-water demand and a preference for compact installation. The unit’s high efficiency helps reduce energy waste, though its GPM ceiling may limit simultaneous usage in very large households.
MIZUDO 180,000 BTU Natural Gas Tankless Water Heater
With up to 7.9 GPM and 180,000 BTU, this model targets larger families and higher hot-water usage points. It includes a sealed combustion system to maintain indoor air quality and CSA-certified protections such as freeze prevention and auto-relight. Choose this if you need robust flow across multiple outlets and value safety features. A limitation is the higher BTU class, which may require a suitable venting setup and professional installation.
ORBEK Natural Gas Tankless Water Heater (Outdoor)
Designed for outdoor installation with 120,000 BTU and 5.1 GPM, this unit suits homes needing on-demand water without indoor exhaust concerns. It emphasizes safe operation with anti-dry burning and anti-flameout protections and uses an advanced control system to minimize temperature fluctuation. Best for outdoor setups or homes prioritizing space flexibility. Limitation: outdoor use requires weatherproofing and protection from extreme conditions.
A. O. Smith Tankless Water Heater – 8 GPM Indoor
This indoor model supports up to 8.0 GPM and 190,000 BTU with X3 scale prevention technology. It aims at consistent hot water and longer component life due to a high-quality copper heat exchanger. Best for larger households or homes with higher simultaneous water use where stability and long-term durability matter. Tends to be a stronger fit when you want higher flow and reliable water temperature control. The trade-off is a larger footprint and higher installation requirements for venting.