Best Gas Control Valves and Thermostats for Water Heaters
Answering the buyer’s search intent: these are reliable gas control valves and thermostats that regulate flame, temperature, and safety for residential water heaters. Best for homeowners upgrading an existing unit, technicians replacing worn parts, and contractors seeking OEM-compatible components. The table below highlights five top options and their best-use scenarios to help you choose quickly.
| Product | Best For | Key Features |
|---|---|---|
| Reliance Water Heater Gas Control Valve, 100112336 (WT8840B 160°F) | Professional installations; older Reliance/Honeywell systems | Ambient 0°C to 60°C; 1″ cavity |
| Reliance Water Heater Natural Gas Control Valve (100112336) | Owners upgrading with compatible brands; note on professional installation | Gas control valve; compatibility with A.O. Smith, Reliance, State, American-brand heaters |
| Rheem AP14270G Gas Control Thermostat | New installs and OEM-compatible replacements | Controls gas flow and water temperature; OEM genuine part |
| Gas Control (Thermostat) – NG (Rheem) | Replacement for NG water heaters; straightforward swap | Gas flow control; water temperature regulation; OEM part |
| 110-326 Gas Water Heater Control Valve (Chuuparts) | Medium to high-temp setups; ECO safety feature | Built-in ECO shutoff at 160°F; 30°C–75°C thermostat; natural gas |
| WV8840B1158 – ClimaTek OEM Upgraded NG Gas Valve | OEM replacement for Honeywell WV8840B series | 2″ cavity; direct replacement; OEM-quality |
Reliance/Honeywell Gas Control Valve – 100112336
This gas control valve is compatible with older Reliance and Honeywell setups and supports ambient operating ranges from 0°C to 60°C. Best for professional installations where existing valve compatibility matches the 1″ cavity design. It is a solid choice for technicians maintaining legacy units. A limitation: installation should typically be done by a trained professional to ensure safe operation and warranty alignment.
Reliance Natural Gas Control Valve – 100112336
Best for compatibility with A.O. Smith, Reliance, State, and American-branded heaters seeking a direct valve replacement. This model emphasizes professional installation and warranty considerations. It’s suited for retrofits where a precise gas control valve is required. Caution: homeowner installation may void warranties and compromise safety if improper wiring or timing is not observed.
Rheem AP14270G Gas Control Thermostat
Best for replacement in Rheem systems needing an OEM-style thermostat that precisely controls gas flow to regulate water temperature. This unit is described as an OEM genuine factory part, aiding compatibility with Rheem/Ruud configurations. Choose this if you want a straightforward fit for compatible Rheem models. A potential limitation is that some installations may require professional service to confirm proper calibration and venting alignment.
Gas Control (Thermostat) – NG (Rheem)
This thermostat governs gas flow and water temperature in natural gas water heaters and is an OEM Genuine Factory Authorized Part. It’s a strong pick when you need a reliable Rheem-compatible control. Consider this option if your unit is designed around Rheem’s gas control protocol. Limitation: verify model compatibility, as mis-matching parts can affect safety and performance.
110-326 Gas Water Heater Control Valve – Chuuparts
Best for replacement in tank-type natural gas heaters with a built-in ECO system. It includes a thermostat range of 30°C–75°C and an ECO that shuts gas when water hits 160°F. Choose this if you need a safety mechanism to prevent overheating. A caveat: ensure the valve’s port sizes and pressures match your appliance’s specifications to avoid improper operation.
ClimaTek WV8840B1158 – OEM Upgraded Valve
This is an OEM-upgraded NG gas valve designed to replace Honeywell WV8840B1158 directly. Best for replacing worn or failing parts in Honeywell-based systems while keeping a high degree of compatibility. Better for users seeking an OEM-equivalent solution with straightforward installation. Limitation: verify the 2″ cavity and mounting fit to avoid fitment issues in tight installations.
Buying Guide: Gas Control Valves And Thermostats For Water Heaters
Key questions to guide your purchase:
- What type of gas is your water heater using (natural gas vs propane) and does the valve support that fuel type?
- Is the valve compatible with your heater’s brand and model, or will a universal/OEM-compatible part be required?
- What is the required temperature range, and does the thermostat meet that range safely?
- Does the unit include an energy cut-off (ECO) or safety mechanism to prevent overheating?
- What professional installation requirements or warranty constraints apply?
Practical guidance:
- For legacy Reliance and Honeywell systems, consider the 100112336 valve with proper cavity sizing and professional installation.
- For modern Rheem configurations, prefer AP14270G or the standard Gas Control Thermostat for straightforward compatibility.
- When replacing a valve in a tank-type heater, confirm inlet/outlet dimensions, mounting fittings, and pressure ratings to avoid leaks and improper combustion.
- Always adhere to local codes and safety standards. If in doubt, hire a licensed technician to install or calibrate the valve and thermostat.
Frequently Asked Questions
- What does a gas control valve do in a water heater?
It regulates the flow of gas to the burner and, often, the water temperature by controlling the flame height. - Do I need a professional to install a gas control valve?
Yes, most modern units require professional installation to ensure safety and warranty compliance. - Can I mix valve brands with my water heater?
Compatibility depends on the model and mounting; mismatches can cause unsafe operation. - What is an ECO on a gas valve?
Energy Cut-Off automatically shuts the gas supply if the water overheats, preventing damage. - Will a replacement valve affect warranty?
It can; check the manufacturer’s warranty terms and ensure proper installation by a qualified technician.