6 Best Alternatives to the Thermomate 98,500 BTU Natural Gas Tankless Water Heater (2026)
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The Thermomate 98,500 BTU Natural Gas Tankless Water Heater delivers stable temperature control and energy efficiency for single-bathroom homes. If you are searching for thermomate 98500 btu natural gas tankless water heater alternatives, you may need a different flow rate, size, or feature set. This unit provides up to 4 GPM with precise heating, but it might not suit larger households or specific installation constraints. You might prefer a model with higher output or a more compact footprint.
We selected these 6 alternatives because their published specifications overlap with the original product’s core capabilities. Each option shares key attributes like natural gas fuel and indoor installation. Some offer higher flow rates for whole-house use, while others focus on precision or durability. This list compares units based strictly on their specs. You can choose the model that best matches your hot water demands and space requirements.
How each alternative compares
Ranein 4.3 GPM Indoor Natural Gas Tankless Water Heater
The Ranein 100,000 BTU model offers a slightly higher flow rate of 4.3 GPM compared to the Thermomate's 4 GPM limit. It uses a copper heat exchanger for durability, similar to the Thermomate's oxygen-free copper design. However, the Ranein is larger, measuring 25.6 inches in height versus 21.7 inches. You get preset modes and LED feedback instead of the Thermomate's advanced chip adjusting heating 20,000 times per second. Choose this if you need a bit more flow and prefer visible status indicators over precise digital control.
VEVOR 4.3 Gal Natural Gas Tankless Water Heater
VEVOR provides 100,000 BTU of power with a 4.3 GPM capacity, exceeding the Thermomate's 98,500 BTU and 4 GPM. It shares the same compact dimensions of 21.7 inches by 13.8 inches, making installation space requirements identical. The VEVOR focuses on precision temperature control and safety features, similar to the Thermomate's ±1°F stability. You trade the Thermomate's specific CSA certification number for VEVOR's whole-house suitability and precise adjustments. Pick this unit if you want slightly higher BTU output and flow while maintaining the same small footprint.
VancEpic 4.8 GPM Natural Gas Tankless Heater
The VancEpic 110,000 BTU heater delivers a significantly higher flow rate of 4.8 GPM, compared to the Thermomate's 4 GPM. It is a non-condensing model, which may affect venting requirements differently than standard indoor units. The unit is larger at 24.6 inches high and weighs 25.4 pounds, versus the Thermomate's 21.2 pounds. You gain higher flow for whole-house use but sacrifice the Thermomate's specific energy efficiency ratings and compact size. Select this if your priority is maximum hot water volume for multiple outlets rather than compactness or peak efficiency.
APUS 4.42 GPM Natural Gas Tankless Water Heater
The APUS 95,000 BTU model offers a 4.42 GPM flow rate, which is higher than the Thermomate's 4 GPM. It is notably more compact, measuring only 5.9 inches in width and length, compared to the Thermomate's 13.8 inches. This slim profile saves significant wall space. You get precise temperature stability and quiet operation, similar to the Thermomate's advanced sensor adjustments. The trade-off is slightly lower BTU output. Choose this APUS unit if you need a very narrow installation space with reliable temperature control and better flow than the original.
Thermomate 5 GPM Indoor Natural Gas Tankless Water Heater
This Thermomate variant provides a higher flow rate of 5.0 GPM, beating the original's 4 GPM capacity. It maintains the same 98,500 BTU power and compact dimensions of 21.7 inches by 13.8 inches. You get stable hot water performance and wind resistance, which are not specified for the original 98,500 BTU model. The weight is similar at 22 pounds. This is the direct upgrade path if you need more simultaneous flow without changing your installation footprint. It keeps the brand's precision control while increasing volume for busy households.
APUS 6.8 GPM Natural Gas Tankless Water Heater
The APUS 140,000 BTU heater offers substantial power and a 6.8 GPM flow rate, far exceeding the Thermomate's 98,500 BTU and 4 GPM. It is designed for whole-house use with multiple simultaneous outlets. The unit is narrow at 7.09 inches wide but weighs 26.9 pounds. You gain high capacity and precise control for large demands. The trade-off is significantly higher energy input and weight. Pick this if you need maximum hot water volume for large homes and do not mind a heavier, more powerful unit compared to the modest original.
Quick picks
Our 7 picks
Thermomate 98,500 BTU Natural Gas Tankless Water Heater
Best for: Single-bathroom households needing stable heat
- Fuel Type
- Natural Gas
- Flow Rate
- Up to 4 GPM
- BTU
- 98,500 BTU
- Installation Location
- Indoor
- Voltage
- 120V
- Temperature Control
- ±1°F
View on Amazon: Thermomate 98,500 BTU Natural Gas Tankless Water Heater Affiliate link
The ThermoMate CZ360NG delivers up to 4 GPM of hot water using 98,500 BTUs of natural gas. It features a copper heat exchanger for 98% thermal efficiency and precise temperature control within ±1°F. This compact unit measures 21.7 inches high and includes multiple safety protections. It suits households needing reliable on-demand heating for one shower and one faucet.
Pros
- 98,500 BTU/hr output for instant hot water
- Up to 4 GPM flow rate
- 98% thermal efficiency with 0.81 UEF
- Temperature stability within ±1°F
- CSA certified with boil-dry and freeze protection
Cons
- Lower flow rate than many competitors
- Indoor installation only
- Heavier than some alternatives
Good fit if
- You need precise temperature control for comfort
- You want high energy efficiency for lower operating costs
- You require CSA certification for safety
Skip if
- You need more than 4 GPM for multiple showers
- You require outdoor installation capability
- You prefer a lighter unit for easier mounting
Verdict: ThermoMate 98,500 BTU Indoor Gas Heater fits single-bathroom homes that prioritize stable water temperature and energy efficiency over high flow volume.
Ranein 4.3 GPM Indoor Natural Gas Tankless Water Heater
Best for: indoor natural gas heating with copper durability
- Fuel Type
- Natural Gas
- Flow Rate
- 4.3 GPM
- BTU
- 100,000 BTU
- Installation Location
- Indoor
- Temperature Control
- 95°F-155°F
- Dimensions
- 25.6 x 16.9 x 16.9 inches
View on Amazon: Ranein 4.3 GPM Indoor Natural Gas Tankless Water Heater Affiliate link
The Ranein 100,000 BTU unit delivers 4.3 GPM for indoor natural gas use. It features an oxygen-free copper heat exchanger and four preset modes for specific tasks. The LED display tracks real-time temperature, which ranges from 95°F to 155°F. Anti-freeze protection helps prevent pipe damage in cold weather. This model supports three to four water points simultaneously.
Pros
- 100,000 BTU output for strong heating performance
- 4.3 GPM flow rate supports multiple fixtures
- Oxygen-free copper heat exchanger resists corrosion
- Four preset modes for kitchen or bathing
- LED display shows real-time water temperature
Cons
- 4.3 GPM flow rate is lower than 4.8 GPM competitors
- Indoor installation only, not suitable for outdoor use
- No smart app or remote control connectivity listed
Good fit if
- You need a reliable indoor natural gas unit
- You want preset modes for different water uses
- You prefer a copper heat exchanger for durability
Skip if
- You require outdoor installation capability
- You need a flow rate above 4.5 GPM
- You want smart app control for your heater
Verdict: The Ranein 100,000 BTU Natural Gas Heater suits homes needing steady indoor performance with copper durability. It fits buyers who value preset modes and clear LED feedback over smart connectivity.
VEVOR 4.3 Gal Natural Gas Tankless Water Heater
Best for: Precision temperature control
- Fuel Type
- Gas
- BTU
- 100,000 BTU/hr
- Installation Location
- Indoor
- Capacity
- 4.3 Gal
- Temperature Control
- ±1°F
- Dimensions
- 21.7 x 13.8 x 13.8 inches
View on Amazon: VEVOR 4.3 Gal Natural Gas Tankless Water Heater Affiliate link
The VEVOR 4.3 Gal unit delivers 100,000 BTU/hr of heating power for indoor whole-house use. It features ±1°F precision temperature control and an LED display for clear monitoring. Weighing 19.8 pounds, it is compact at 21.7 x 13.8 x 13.8 inches. This gas heater offers multiple security protections and standard 1/2 inch NPT connectors for straightforward installation.
Pros
- 100,000 BTU/hr heating capacity
- ±1°F precision temperature control
- LED display for real-time status
- Multiple security protections included
Cons
- 4.3 GPM flow rate is lower than competitors
- 100,000 BTU is less than some alternatives
- No remote control listed in specifications
Good fit if
- You need precise temperature stability
- You want a compact indoor unit
- You prefer LED display feedback
Skip if
- You require higher flow rates
- You need propane fuel options
- You want remote control access
Verdict: VEVOR 4.3 Gal 100,000 BTU Gas Heater suits users prioritizing temperature precision and safety features over maximum flow rate.
VancEpic 4.8 GPM Natural Gas Tankless Heater
Best for: Whole-house hot water with high flow
- Fuel Type
- Natural Gas
- Flow Rate
- 4.8 GPM
- BTU
- 110,000 BTU
- Installation Location
- Indoor
- Temperature Control
- ±1°F
- Dimensions
- 24.6 x 14.4 x 14.4 in
View on Amazon: VancEpic 4.8 GPM Natural Gas Tankless Heater Affiliate link
This VancEpic unit delivers 4.8 GPM at 110,000 BTU for indoor natural gas use. It features a non-condensing design with an oxygen-free copper heat exchanger. Temperature control stays within ±1°F, ensuring stable output. The compact build measures 24.6 x 14.4 x 14.4 inches. It supports 3-5 water outlets, making it suitable for family homes seeking consistent hot water flow.
Pros
- High 110,000 BTU output for rapid heating
- 4.8 GPM flow rate supports multiple fixtures
- ±1°F precise temperature control prevents fluctuations
- Oxygen-free copper heat exchanger for durability
Cons
- Non-condensing technology offers lower efficiency than condensing models
- 2-year warranty is shorter than typical industry standards
- Lacks smart app connectivity for remote monitoring
Good fit if
- You need high flow rates for whole-house use
- You prefer precise temperature stability
- You want a compact indoor installation
Skip if
- You require maximum energy efficiency
- You want long-term warranty coverage
- You need smart home integration
Verdict: VancEpic 110,000 BTU Natural Gas Heater fits buyers who prioritize flow rate and temperature precision over efficiency. It is a solid choice for indoor whole-house setups where consistent hot water is the main goal.
APUS 4.42 GPM Natural Gas Tankless Water Heater
Best for: indoor homes needing precise temperature stability
- Fuel Type
- Natural Gas
- Flow Rate
- 4.42 GPM
- BTU
- 95,000 BTU
- Installation Location
- Indoor
- Voltage
- 120V AC
- Temperature Control
- 95°F–140°F (±1°F)
View on Amazon: APUS 4.42 GPM Natural Gas Tankless Water Heater Affiliate link
The APUS 95,000 BTU unit delivers 4.42 GPM of hot water for indoor use. It features an oxygen-free copper heat exchanger and smart CPU technology to maintain temperature within ±1°F. The compact design measures 20.55 x 13.27 x 5.91 inches. It operates quietly at 36dB and includes built-in freeze protection. This model suits households needing steady flow for multiple fixtures.
Pros
- 95,000 BTU heating capacity with 4.42 GPM flow rate
- Temperature control within ±1°F of desired setting
- 98% thermal efficiency with 0.81 UEF rating
- Quiet operation at 36dB
- Built-in freeze protection activates below 41°F
Cons
- Shorter 2-year warranty compared to industry standards
- Lower 95,000 BTU capacity than some competitors
- Indoor installation only
Good fit if
- You need precise temperature stability within ±1°F
- You require a compact unit for tight indoor spaces
- You want quiet operation at 36dB
Skip if
- You need outdoor installation capability
- You require a warranty longer than 2 years
- You need higher than 4.42 GPM flow rate
Verdict: APUS 95,000 BTU Natural Gas Water Heater offers precise temperature control and quiet operation for indoor residential use. It fits buyers who prioritize steady water temperature and compact dimensions over maximum BTU output.
Thermomate 5 GPM Indoor Natural Gas Tankless Water Heater
Best for: indoor homes needing stable 5 GPM flow
- Fuel Type
- Natural Gas
- Flow Rate
- Up to 5 GPM
- BTU
- 102,000 BTU
- Installation Location
- Indoor
- Voltage
- 120V
- Temperature Control
- 90–140°F, ±1°F
View on Amazon: Thermomate 5 GPM Indoor Natural Gas Tankless Water Heater Affiliate link
This ThermoMate unit delivers up to 5 GPM with 113,000 BTU of heating power. It maintains a stable 105°F output and adjusts temperature between 90–140°F with ±1°F consistency. The compact 21"H x 13"W x 7"D design fits indoor spaces efficiently. It includes a smart LED display and wind-resistant fan for reliable operation in various weather conditions.
Pros
- Up to 5.0 GPM flow rate for simultaneous use
- 113,000 BTU heating capacity with 98% thermal efficiency
- Wind-resistant DC fan withstands Category 3+ winds
- Smart LED display shows flow, fan, and flame status
Cons
- Indoor installation only
- Requires 120V electrical connection
- Heavier at 22 pounds
Good fit if
- You need hot water for two showers at once
- You have an indoor space with 120V power
- You want precise temperature control within ±1°F
Skip if
- You require outdoor installation
- You need more than 5 GPM flow
- You prefer propane fuel over natural gas
Verdict: ThermoMate 5 GPM Natural Gas Heater provides stable hot water for busy households with its high flow rate and precise temperature control. It suits buyers who need reliable indoor performance and wind resistance for their natural gas setup.
APUS 6.8 GPM Natural Gas Tankless Water Heater
Best for: Whole-house high-flow needs
- Fuel Type
- Natural Gas
- Flow Rate
- Up to 6.8 GPM
- BTU
- 140,000 BTU
- Installation Location
- Indoor
- Voltage
- 120V AC
- Temperature Control
- 95–140°F, ±1°F
View on Amazon: APUS 6.8 GPM Natural Gas Tankless Water Heater Affiliate link
This APUS unit delivers 140,000 BTU and up to 6.8 GPM for whole-house use. It features a built-in booster pump and zero cold water technology. The LED display allows precise temperature control from 95 to 140°F. It is designed for indoor installation. The compact size fits standard connections. You get reliable hot water for multiple outlets.
Pros
- 140,000 BTU output for high flow
- Built-in booster pump increases flow by 130%
- Precise ±1°F temperature control
- Zero cold water technology reduces wait time
- Compact indoor design with standard NPT connections
Cons
- Requires 120V AC power for pump and controls
- Must be drained in freezing conditions to prevent damage
- App control requires Tuya setup
Good fit if
- You need high flow for 4–5 water points
- You want precise temperature adjustments
- You have indoor space for installation
Skip if
- You need outdoor installation
- You lack a 120V AC outlet nearby
- You live in a freezing climate without drainage plans
Verdict: APUS 140,000 BTU Natural Gas Tankless Heater suits homes needing high flow and precise control. It is ideal for whole-house use with multiple simultaneous outlets.
Specifications side by side
| Spec | Thermomate 98,500 BTU Natural Gas Tankless Water Heater | Ranein 4.3 GPM Indoor Natural Gas Tankless Water Heater | VEVOR 4.3 Gal Natural Gas Tankless Water Heater | VancEpic 4.8 GPM Natural Gas Tankless Heater | APUS 4.42 GPM Natural Gas Tankless Water Heater | Thermomate 5 GPM Indoor Natural Gas Tankless Water Heater | APUS 6.8 GPM Natural Gas Tankless Water Heater |
|---|---|---|---|---|---|---|---|
| Fuel Type | Natural Gas | Natural Gas | Gas | Natural Gas | Natural Gas | Natural Gas | Natural Gas |
| Flow Rate | Up to 4 GPM | 4.3 GPM | not stated | 4.8 GPM | 4.42 GPM | Up to 5 GPM | Up to 6.8 GPM |
| BTU | 98,500 BTU | 100,000 BTU | 100,000 BTU/hr | 110,000 BTU | 95,000 BTU | 102,000 BTU | 140,000 BTU |
| Installation Location | Indoor | Indoor | Indoor | Indoor | Indoor | Indoor | Indoor |
| Capacity | not stated | not stated | 4.3 Gal | not stated | not stated | not stated | not stated |
| Voltage | 120V | not stated | not stated | not stated | 120V AC | 120V | 120V AC |
| Temperature Control | ±1°F | 95°F-155°F | ±1°F | ±1°F | 95°F–140°F (±1°F) | 90–140°F, ±1°F | 95–140°F, ±1°F |
| Certification | CSA | not stated | not stated | not stated | not stated | CSA, UL | not stated |
| Dimensions | 21"H × 13"W × 7"D | 25.6 x 16.9 x 16.9 inches | 21.7 x 13.8 x 13.8 inches | 24.6 x 14.4 x 14.4 in | 20.55"H × 13.27"W × 5.91"D | 21"H × 13"W × 7"D | 21.26 × 13.58 × 7.09" |
| Use | not stated | Whole House | Whole House | not stated | not stated | not stated | Whole House |
| Venting Type | not stated | not stated | not stated | Non-Condensing | not stated | not stated | not stated |
| Weight | 21.2 pounds | not stated | 19.8 pounds | 25.4 pounds | 19.2 pounds | 22 pounds | 26.9 pounds |
| Color | Silver | Gray-NG | Silver Gray | Non-Condensing | Natural Gas,4.42GPM,95,000BTU，Space Gray | Metallic Silver | Space Gray |
| Model | CZ360NG | RH10K | JSQ30-A | VH11K-W-NG-U01 | AP-AWH-Q13NG | CZ422NG | AP-AWH-Q20NG |
| Size | not stated | 4.3 GPM Indoor | 4.3 Gal | 4.8GPM, 110,000BTU, NG | not stated | not stated | not stated |
You can compare output ratings across the best natural gas tankless water heaters to size your system.
Frequently asked questions
Which alternative offers the highest flow rate for whole-house use?
The APUS 6.8 GPM model provides the highest flow rate on this list. It delivers 140,000 BTU of power to support multiple simultaneous outlets. This unit is designed for whole-house applications where high volume is critical. Its compact width of 7.09 inches allows for flexible installation in tight spaces.
How does the VancEpic differ in venting technology?
The VancEpic 4.8 GPM model is a non-condensing unit. This distinguishes it from many modern condensing heaters by using a different exhaust mechanism. It offers 110,000 BTU output with a 4.8 GPM flow rate. This setup suits buyers who prioritize flow and temperature precision over maximum efficiency ratings.
Which model is the most compact in width?
The APUS 4.42 GPM model is the narrowest option listed. It measures just 5.9 inches in width and length. Despite its small footprint, it provides 95,000 BTU of heating power. This makes it an ideal choice for installations where space is limited but stable indoor performance is required.
Does the Ranein model include specific durability features?
Yes, the Ranein 4.3 GPM model features a copper heat exchanger. This design prioritizes durability for indoor natural gas heating. It delivers 100,000 BTU with a 4.3 GPM flow rate. The unit also includes preset modes and LED feedback, catering to users who value clear operational indicators over smart connectivity.
Which heater is best for precision temperature control?
The VEVOR 4.3 Gal model is highlighted for precision temperature control. It offers 100,000 BTU output with a 4.3 GPM flow rate. This unit includes safety features and is designed for whole-house use. It suits users who prioritize stable water temperatures and safety over maximum flow volume in their daily routine.
What is the flow rate of the Thermomate 5 GPM alternative?
The Thermomate 5 GPM Indoor Natural Gas Tankless Water Heater provides a steady 5.0 GPM flow rate. It is designed for busy households needing reliable indoor performance. The unit includes wind resistance features for natural gas setups. Its dimensions are 13.8 inches wide and 21.7 inches tall.
Which alternative is best for single-bathroom stability?
The original Thermomate 98,500 BTU model remains the top pick for single-bathroom homes. It prioritizes stable water temperature and energy efficiency over high flow volume. The unit measures 13.8 inches in width and length. It is an indoor natural gas heater weighing 21.2 pounds.
How heavy is the VancEpic unit compared to others?
The VancEpic 4.8 GPM model weighs 25.4 pounds. This makes it the heaviest unit on this specific list. It offers 110,000 BTU of power with a non-condensing design. The unit measures 14.4 inches in width and 24.6 inches in height for indoor installation.