Natural Gas Tankless Water Heaters
Upgrade your home hot water system with a natural gas tankless water heater designed for efficient whole-home performance. Unlike traditional storage tank water heaters, tankless natural gas models heat water only when needed, helping reduce standby energy waste while providing continuous hot water for showers, sinks, kitchens, and daily household use. ThermoMate natural gas tankless water heaters are ideal for homeowners who want a space-saving, high-efficiency solution for reliable hot water throughout the home. Whether you are replacing an old tank system or planning a new installation, choosing the right GPM and BTU output can help ensure your household has enough hot water for multiple fixtures and bathrooms.
Built for Whole-Home Hot Water Needs
A natural gas tankless water heater is a strong choice for whole-house use when properly sized for your home’s hot water demand. Instead of storing a limited amount of preheated water, a tankless system heats water on demand, allowing your household to enjoy continuous hot water for daily routines.
ThermoMate natural gas tankless water heaters are designed to support everyday residential hot water needs while helping save space compared with bulky storage tank systems. For larger households or homes with multiple fixtures running at the same time, choosing a higher GPM model is especially important.
- Multiple bathrooms
- Showers and bathroom sinks
- Kitchen sinks
- Laundry rooms
- Medium to large households
- Homes replacing traditional tank water heaters
Why Choose a Natural Gas Tankless Water Heater?
Continuous Hot Water
Tankless natural gas water heaters heat water on demand, making them suitable for daily showers, sinks, and whole-home hot water use.
Space-Saving Design
Without a bulky storage tank, a tankless system helps free up space in utility rooms, garages, basements, and compact home layouts.
Great for Gas-Connected Homes
If your home already has a natural gas line, a natural gas tankless water heater can be a convenient choice for reliable hot water.
How to Choose the Right GPM
GPM stands for gallons per minute, which measures how much hot water a tankless water heater can deliver at one time. The right GPM depends on how many fixtures you expect to use simultaneously, your incoming groundwater temperature, and your household’s daily hot water habits.
For two bathrooms, a natural gas tankless water heater around 4.5–6.0 GPM is often a practical choice, depending on whether both showers may run at the same time.
| Household Need | Suggested GPM Range | Best For |
|---|---|---|
| 1 bathroom or light use | 2.5–3.5 GPM | Small homes, apartments, guest houses |
| 1–2 fixtures at the same time | 3.5–4.5 GPM | Small to medium homes |
| 2 bathrooms or multiple fixtures | 4.5–6.0 GPM | Medium homes, families, daily whole-home use |
| Larger homes or higher demand | 6.0+ GPM | Larger households, simultaneous showers and sinks |
1 Bathroom or Light Use
Suggested GPM: 2.5–3.5 GPM
Best For: Small homes, apartments, guest houses
1–2 Fixtures at the Same Time
Suggested GPM: 3.5–4.5 GPM
Best For: Small to medium homes
2 Bathrooms or Multiple Fixtures
Suggested GPM: 4.5–6.0 GPM
Best For: Medium homes, families, daily whole-home use
Larger Homes or Higher Demand
Suggested GPM: 6.0+ GPM
Best For: Larger households, simultaneous showers and sinks
Installation and Venting Considerations
Indoor natural gas tankless water heaters require proper venting because gas combustion produces exhaust that must be safely directed outdoors. Installation should follow the product manual, local building codes, and gas safety requirements.
Before choosing a natural gas tankless water heater, consider gas line capacity, venting requirements, water pressure, groundwater temperature, fixture flow rates, and professional installation needs. Correct installation is essential for safe operation, stable performance, and long-term reliability.
Natural Gas Tankless Water Heater FAQ
Is a natural gas tankless water heater good for a whole house?
Yes. A natural gas tankless water heater can be a good option for whole-house use when it is properly sized for your household’s hot water demand. For homes with multiple bathrooms or several fixtures running at the same time, choose a model with enough GPM and BTU output to support simultaneous use.
What GPM do I need for two bathrooms?
For two bathrooms, many homes may need around 4.5–6.0 GPM, depending on fixture flow rates, incoming water temperature, and whether both showers may be used at the same time. If your household often runs showers, sinks, or appliances simultaneously, choosing a higher GPM natural gas tankless water heater can help maintain more consistent hot water performance.
Does a natural gas tankless water heater need venting?
Yes. Indoor natural gas tankless water heaters require proper venting to safely remove combustion exhaust. Venting requirements vary by model and installation location, so always follow the product manual and local building codes. Professional installation is strongly recommended.
How long does a natural gas tankless water heater last?
A natural gas tankless water heater can often last many years with proper installation, regular maintenance, and suitable water quality. Service life depends on usage frequency, maintenance, water hardness, installation conditions, and product design. Routine flushing and inspection can help support long-term performance.
Natural gas vs propane tankless water heater, which is better?
Both natural gas and propane tankless water heaters can provide efficient on-demand hot water. Natural gas is usually better for homes already connected to a gas utility line because fuel supply is convenient and continuous. Propane is often better for cabins, rural homes, tiny homes, RV-related applications, and off-grid locations where natural gas is not available. The better choice depends on your fuel access, installation environment, hot water demand, and local energy costs.