Thermomate vs APUS: Tankless Water Heaters Compared by Specs
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The thermomate vs APUS tankless water heater debate centers on your water needs and power source. Both units deliver hot water efficiently, but they serve different environments. Thermomate offers a small electric tank for under-sink use in homes. APUS provides a propane-powered unit designed for RVs. Your choice depends on whether you need stationary point-of-use heating or mobile on-demand hot water for travel.
Key differences
| Aspect | Thermomate 6.5-Gallon Under-Sink Electric Mini-Tank | APUS 68,000 BTU RV Propane Water Heater |
|---|---|---|
| Fuel Type | Electric | Propane |
| Capacity | 6.5 Gallons | Tankless (3.9 GPM) |
| Voltage | 120 V | 12V DC |
| Primary Use | Under Sink | RV |
| Certification | UL Listed | CSA Certified |
Which one should you choose?
Choose Thermomate 6.5-Gallon Under-Sink Electric Mini-Tank if
- You need hot water for a kitchen or bathroom sink in a stationary home.
- You have access to a standard 120V electrical outlet under your counter.
- You prefer a compact storage tank that reduces wait times for small uses.
Choose APUS 68,000 BTU RV Propane Water Heater if
- You are installing water heating in an RV, camper, or travel trailer.
- You want on-demand hot water without the weight and space of a storage tank.
- You are using propane fuel and 12V DC power typical in recreational vehicles.
Verdict: Choose the Thermomate if you need a reliable, compact hot water source for a fixed under-sink location in your home. Pick the APUS if you are outfitting an RV and need a propane-powered, tankless solution that fits standard compartments. The right unit depends entirely on your fuel source and whether you are stationary or mobile.
Thermomate vs APUS Specs Compared
Fuel type
Thermomate uses 120-volt electricity, making it suitable for standard home outlets in kitchens or bathrooms. You plug it directly into a wall socket. APUS runs on propane, which is essential for RVs or off-grid setups where electrical power is limited. Propane provides consistent heat regardless of your electrical grid status. This fundamental difference dictates where each unit can operate. You must choose based on your available energy source. Electric is convenient for stationary home use, while propane offers mobility and independence for travel.
Flow rate
APUS delivers up to 3.9 gallons per minute (GPM), allowing for full showers and simultaneous sink use without significant pressure drop. Thermomate is a 6.5-gallon mini-tank designed for point-of-use applications. It does not list a continuous flow rate because it stores heated water. It provides instant hot water from a stored reserve rather than heating water on the fly. For a single sink, Thermomate is sufficient. For showers or multiple fixtures, APUS offers superior continuous flow capability, making it the better choice for higher demand scenarios.
Capacity
Thermomate holds 6.5 gallons of pre-heated water, providing a buffer for short bursts of use. This tank capacity helps maintain temperature during brief intervals. APUS has no tank, relying on a 68,000 BTU burner to heat water continuously as it flows. While APUS lacks storage, its high BTU output ensures a steady supply. Thermomate’s tank is ideal for under-sink tasks like dishwashing where intermittent use is common. APUS is better for sustained hot water needs like showering. Your choice depends on whether you need stored reserves or continuous on-demand flow.
Installation location
Thermomate is designed for under-sink or under-counter installation in homes. Its compact dimensions fit standard cabinetry, and it mounts to walls or floors. APUS is built to replace standard RV water heater compartments, fitting most 14.96 x 14.96-inch openings. It is compatible with 12V DC power systems found in vehicles. Thermomate requires a standard 120V household outlet. APUS requires propane connections and 12V power. You must select Thermomate for fixed home locations and APUS for mobile or RV environments where space and power differ significantly.
Temperature control
Thermomate offers three temperature settings ranging from 50°F to 149°F, with a freeze mode to prevent damage. This manual control allows you to adjust heat for specific tasks. APUS features intelligent staged combustion that automatically adjusts heating based on incoming water temperature and flow. It maintains a comfortable 95–124°F outlet temperature while reducing propane consumption. APUS also includes a remote control for easy adjustment. Thermomate relies on a local thermostat. APUS provides more precise, automated temperature management with remote accessibility, whereas Thermomate offers simple manual adjustment.
Certification
Thermomate is UL Listed, ensuring it meets safety standards for residential electrical appliances in the United States. This certification covers electrical safety and insulation quality. APUS is CSA Certified, which is the standard for gas appliances, particularly those used in RVs and mobile homes. CSA certification verifies safe combustion and gas handling. Both units meet rigorous safety protocols for their respective fuel types. You can trust Thermomate for electrical safety in homes and APUS for gas safety in vehicles. The certifications reflect the distinct operational environments each unit serves.
Which unit fits your hot water needs
Homeowners needing under-sink hot water
This Thermomate unit plugs into standard 120V outlets, making installation simple in kitchens or bathrooms. Its 6.5-gallon tank provides instant hot water for point-of-use tasks. The adjustable thermostat allows temperatures from 50°F to 149°F, ensuring safe and comfortable water for dishwashing or handwashing without complex venting requirements.
RV owners seeking endless hot water
The APUS heater delivers continuous hot water at 3.9 GPM using propane, ideal for long showers in travel trailers. It fits standard RV compartments and operates at elevations up to 9,800 feet. The included remote control lets you adjust temperatures from inside the vehicle, offering convenience for mobile living.
Campers needing reliable off-grid performance
This propane model starts with just 0.55 GPM flow, conserving water and fuel during camping trips. Intelligent freeze protection activates at 35.6°F to prevent damage. CSA certification ensures safety with features like flame failure and gas leak protection, making it a dependable choice for outdoor adventures and remote locations.
The products compared
Thermomate 6.5-Gallon Under-Sink Electric Mini-Tank
Best for: Under-sink hot water for single faucets
- Fuel Type
- Electric
- Wattage
- 1.44 kW
- Capacity
- 6.5 Gallons
- Voltage
- 120V
- Temperature Control
- 50°F to 149°F
- Certification
- UL Listed
View on Amazon: Thermomate 6.5-Gallon Under-Sink Electric Mini-Tank Affiliate link
This Thermomate unit is a 6.5-gallon electric mini tank water heater designed for point-of-use installation. It operates on 120V power with a 1.44 kW heating element. The glass-lined tank offers 99% thermal efficiency. You can adjust the temperature between 50°F and 149°F. Its compact 17.7 x 17.7 x 14.6 inch size fits under sinks. It includes UL listing for safety and a 3-year tank warranty.
Pros
- 6.5-gallon capacity provides instant hot water for sinks
- Adjustable thermostat ranges from 50°F to 149°F
- UL Listed for safety with glass-lined tank
- Compact dimensions fit under most standard sinks
Cons
- Requires a dedicated 120V electrical outlet
- Limited to point-of-use applications only
- Smaller capacity than whole-house tankless systems
Good fit if
- You need hot water for a single sink
- You have a 120V outlet near the installation site
- You want a compact under-sink solution
Skip if
- You require hot water for multiple fixtures
- You only have a 240V electrical supply
- You need a whole-house water heating system
Verdict: Thermomate 6.5 Gal Mini Tank Electric Heater is a practical solution for under-sink hot water needs. It suits users who need a compact, electric-powered unit with adjustable temperature settings for a single faucet.
APUS 68,000 BTU RV Propane Water Heater
Best for: RVers replacing small tank heaters
- Fuel Type
- Propane
- Flow Rate
- 3.9 GPM
- BTU
- 68,000 BTU
- Voltage
- 12V DC
- Certification
- CSA
- Dimensions
- 14.96 x 14.96 x 14.18 inches
View on Amazon: APUS 68,000 BTU RV Propane Water Heater Affiliate link
This APUS unit delivers 68,000 BTU of heat for up to 3.9 GPM of hot water. It runs on propane with 12V DC power. The compact 14.96-inch square design fits standard RV compartments. It includes a remote control for indoor temperature adjustment. You get reliable performance at elevations up to 9,800 ft. This heater replaces smaller tank models in travel trailers and motorhomes.
Pros
- High 68,000 BTU output for steady hot water
- Includes remote control for indoor temperature settings
- Compact dimensions fit most standard RV openings
- Operates at elevations up to 9,800 ft
Cons
- Propane fuel requires a gas connection
- White door finish may not match all RV styles
- No electric heating option for dual-fuel flexibility
Good fit if
- You need endless hot water in an RV
- You want to replace a 6-gallon tank heater
- You camp at high elevations
Skip if
- You prefer electric-only power sources
- You need a black door finish
- You require indoor installation away from the exterior
Verdict: APUS RV Propane Tankless Water Heater offers strong heat output and a convenient remote for RV travelers. It fits standard compartments and handles high-altitude camping well. This unit suits those replacing small tank heaters with on-demand propane power.
Specifications side by side
| Spec | Thermomate 6.5-Gallon Under-Sink Electric Mini-Tank | APUS 68,000 BTU RV Propane Water Heater |
|---|---|---|
| Fuel Type | Electric | Propane |
| Flow Rate | not stated | 3.9 GPM |
| BTU | not stated | 68,000 BTU |
| Wattage | 1.44 kW | not stated |
| Capacity | 6.5 Gallons | not stated |
| Voltage | 120V | 12V DC |
| Temperature Control | 50°F to 149°F | not stated |
| Certification | UL Listed | CSA |
| Dimensions | 17.7"H x 17.7"W x 14.6"D | 14.96 x 14.96 x 14.18 inches |
| Use | Under Sink | RV |
| Weight | 26.5 pounds | 24 pounds |
| Size | 6.5 Gallon | not stated |
| Color | white,blue | White |
| Model | ES700 | AP-AWH-RV10W-NEW |
Frequently asked questions
Can I install the Thermomate under a standard kitchen sink?
Yes, the Thermomate 6.5-gallon unit fits most under-sink spaces. Its dimensions are 14.6 inches wide, 17.7 inches long, and 21.2 inches high. This compact size allows it to sit securely on the floor beneath a single faucet. It requires a standard 120-volt electrical outlet for operation.
Is the APUS heater suitable for high-altitude camping?
Yes, the APUS 68,000 BTU propane unit is designed to handle high-altitude conditions. It delivers consistent heat output even when air density is lower. This makes it a reliable choice for RV travelers who camp in mountainous regions or elevated areas where standard heaters might struggle.
Does the APUS come with a remote control?
Yes, the APUS RV Propane Water Heater includes a remote control. This feature allows you to adjust settings without reaching the unit itself. It adds convenience for RVers who need to manage the heater from inside the vehicle or from a distance.
What is the weight difference between the two heaters?
The Thermomate weighs 26.5 pounds, while the APUS weighs 24 pounds. The Thermomate is slightly heavier due to its 6.5-gallon tank construction. The APUS is lighter, which may matter if you need to move the RV unit frequently or access tight storage compartments.
Can I use the Thermomate for multiple faucets?
No, the Thermomate is designed for single-faucet use. It is best suited for under-sink hot water needs at one specific location. If you need hot water for multiple fixtures, you would need additional units or a different whole-house solution.
How does the fuel type affect installation?
The Thermomate uses 120-volt electricity, requiring only a wall outlet. The APUS uses propane, which needs a gas line connection. Your installation depends on your available power source. Electric units are easier for standard homes, while propane units are essential for off-grid or RV setups.
What are the dimensions of the APUS heater?
The APUS unit measures 14.2 inches in width, length, and height. This cube-like shape allows it to fit into standard RV compartments. Its compact footprint ensures it does not take up excessive space in your vehicle while providing on-demand hot water.