Answering the question “which gas water heater should I buy?” this guide highlights practical, on-demand gas-powered options for homes and RVs. It features reliable valves, compact tankless models, and hybrid setups that suit different households. Best for homeowners replacing aging units, best for RV living, and best for budget-conscious buyers, these picks balance efficiency, safety, and ease of use. The top five products below are selected for relevance to older gas systems, compatibility considerations, and clear consumer guidance.
Product Overview Table
| Product | Best For | Key Benefit |
|---|---|---|
| Reliance Gas Control Valve 100112336 | Homeowners with older Reliance/A.O. Smith style heaters | Professional installation recommended; enhances compatibility with branded heaters |
| Natural Gas Tankless Water Heater, 4.21 GPM (forimo) | Homes with demand for on-demand hot water | Low water pressure requirement; digital temperature control |
| ORBEK RV Tankless Water Heater | RV households and campers | 12V DC operation with remote; CSA certified |
| Rinnai RX199iN Condensing Tankless | Homes needing high flow and indoor/outdoor flexibility | Versa Vent; high efficiency; propane or natural gas |
| FOGATTI Natural Gas Tankless Indoor 7.5 GPM | High-demand households with space savings | Compact design; 170,000 BTU; on-demand performance |
Reliance Gas Control Valve 100112336
The Reliance control valve is designed for compatibility with A.O. Smith, Reliance, State, and American-branded water heaters. It is a gas valve component intended for professional installation, and installation by a homeowner could void warranty coverage. This valve offers value by enabling compatibility with older gas-fired systems and facilitating safe, regulated gas flow. Best for: service professionals upgrading legacy units or installers replacing end-of-life parts. Limitation: requires professional installation to avoid warranty issues and improper operation.
Natural Gas Tankless Water Heater (forimo) 4.21 GPM
This 4.21 GPM tankless unit provides on-demand hot water with a digital Fahrenheit display and multiple protections. It operates at low inlet pressure and is suitable for small to mid-sized households needing steady temperature control. Best for: homes with modest hot-water demand seeking an energy-efficient, compact solution. Caution: ensure proper venting and gas line sizing per local codes to optimize performance.
ORBEK RV Tankless Water Heater
ORBEK’s RV unit is designed for mobile living and runs on propane with 12V DC ignition. It features copper heat exchangers, staged combustion, and a remote control for convenient operation. Best for: RV families seeking reliable hot water on the road while minimizing energy use. Limitation: RV installation requires careful venting and space planning; not a general home unit.
Rinnai RX199iN Condensing Tankless
This model offers indoor or outdoor installation with Versa Vent and supports propane or natural gas. It provides up to 11.1 GPM, making it suitable for larger households or multi-point hot-water needs. Best for: homeowners needing high flow with flexible installation. Caution: ensure proper venting and a compatible Wi-Fi control module if remote monitoring is desired.
FOGATTI Natural Gas Tankless Indoor 7.5 GPM
FOGATTI’s 7.5 GPM unit delivers immediate hot water with a high BTU rating and a compact footprint. It supports multiple outlets and provides precision temperature control via its four-stage combustion system. Best for: households needing strong on-demand performance without taking up much space. Limitation: higher BTU units may require structural considerations for proper venting and gas supply.
Buying Guide
What should I consider when choosing a gas water heater?
Key factors include capacity and flow rate (GPM), venting requirements, and whether the system is tankless or has a storage tank. Tankless models save space and energy but may have higher upfront costs and installation complexity. Storage-tank units provide steady supply but take more space and can lose heat over time.
Is this unit compatible with my existing setup?
Check gas type (natural gas vs. propane), venting compatibility, and connector sizing. For older systems, compatibility with existing valves or the need for professional replacement parts should influence the selection. Some parts require a licensed technician to install and avoid warranty issues.
What about installation and safety?
Gas appliances require proper ventilation, gas line sizing, and pressure testing. Units that include advanced safety features like flame failure devices and overheat protection should be prioritized. Always follow local codes and manufacturer recommendations for installation.
Which features improve efficiency?
Condensing designs, high fuel efficiency (UEF or equivalent), and precise temperature controls help reduce energy use. Digital displays and remote monitoring add convenience for households seeking better control and data on hot-water usage.
RV-specific considerations
RV tankless heaters must operate on 12V DC or compatible power sources and fit within compact cutouts. Solar or engine-based power considerations, along with proper venting, are essential for reliable performance on the road.
FAQ
- What’s the difference between tankless and traditional gas water heaters? Tankless models provide on-demand hot water with no storage tank, saving space and energy, but may require higher upfront costs and careful sizing for several outlets.
- Can I install a gas water heater myself? Some components may be user-serviceable, but most gas water heaters require professional installation to ensure safety and warranty validity.
- Which heater is best for high hot-water demand? High-flow tankless units (up to 11+ GPM) are better for busy households with multiple simultaneous hot-water needs.
- Are RV tankless heaters safe for travel? Yes, when installed properly with appropriate venting and power provisions, they can provide reliable hot water for mobile living.
- What should I check before buying an old gas water heater? Verify compatibility with existing gas type, venting system, space constraints, and whether replacement parts are readily available from the brand.
- Do these heaters require regular maintenance? Yes; periodic flushing, vent inspection, and checking for gas leaks help maintain efficiency and safety.