APUS Propane Tankless Water Heater vs APUS 18kW Tankless Water Heater: Spec Comparison
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You are comparing the apus propane tankless water heater vs 18kw tankless water heater to find the right unit for your home. Both APUS models provide on-demand hot water with similar flow rates around 4.4 GPM. They share digital controls and safety features. The main difference is the energy source. One uses propane gas for higher heating capacity, while the other uses electricity for ultra-slim installation. This choice affects your wiring, venting, and where you can place the unit.
Key differences
| Aspect | APUS 95,000 BTU 4.42 GPM Indoor Propane Heater | APUS 18kW 4.4 GPM Tankless Water Heater |
|---|---|---|
| Fuel Type | Propane | Electric |
| Voltage | 120V AC | 240V |
| Heating Capacity | 95,000 BTU | 18kW |
| Flow Rate | 4.42 GPM | 4.4 GPM |
| Dimensions | 20.55 x 13.27 x 5.91 inches | 13.7 x 11.42 x 3.54 inches |
| Installation Location | Indoor | Indoor |
Which one should you choose?
Choose APUS 95,000 BTU 4.42 GPM Indoor Propane Heater if
- You need higher heating capacity to handle multiple simultaneous showers in colder climates.
- You want a unit that connects to a standard 120V outlet without heavy electrical upgrades.
- You prefer precise temperature stability with a wider adjustable range from 95°F to 140°F.
Choose APUS 18kW 4.4 GPM Tankless Water Heater if
- You want the most compact unit possible to save space in a small utility area.
- You already have the required 240V electrical circuit and 40A breakers installed.
- You prioritize 99.8% thermal efficiency with self-modulating technology to reduce standby energy loss.
Verdict: Choose the propane model if you need robust heating power for whole-house use or lack the electrical infrastructure for high-voltage units. Select the 18kW electric model if space is tight and you have the necessary 240V wiring ready. Both deliver steady hot water, so your decision rests on fuel availability and installation constraints.
APUS Propane vs Electric Spec Comparison
fuel type
Product A runs on propane, while Product B uses electricity. This difference dictates your entire setup. Propane offers independence from grid power, useful in areas with unreliable electricity or during outages. Electric units require a stable electrical supply. You must choose based on your home’s existing fuel infrastructure. If you already have a propane tank or line, Product A fits seamlessly. If you have robust electrical service, Product B is a straightforward option. Neither fuel type is inherently superior; the choice depends on what is already available in your home.
voltage requirements
The electrical needs differ significantly between these two models. Product A requires a standard 120V AC connection, which is common in most households and easy to integrate. Product B demands a dedicated 240V circuit, two 40A breakers, and 8 AWG wire. This higher voltage requirement means Product B likely needs professional installation by an electrician. If you want a simpler electrical hookup that plugs into a standard outlet, Product A is the easier choice. Product B’s heavy electrical demands make it less suitable for homes without existing high-voltage infrastructure.
thermal efficiency
Product B boasts a thermal efficiency of 99.8%, which is exceptionally high for electric resistance heating. Product A lists a UEF of 0.81 and up to 98% thermal efficiency for its propane combustion. Both units are highly efficient, minimizing wasted energy. Product B’s self-modulating technology adjusts power to flow rate, reducing standby loss. Product A uses segmented combustion for similar savings. While the percentages are close, electric heating typically converts nearly all energy to heat, giving Product B a slight edge in pure conversion efficiency. However, propane energy density may offer different real-world savings depending on local utility costs.
installation location
Product A is rated for indoor installation only. This restricts where you can place it, requiring a location with adequate ventilation and protection from the elements. Product B’s compact, wall-mounted design is suitable for whole-house or point-of-use installation, though specific outdoor ratings are not listed in the data. Generally, electric units can be more flexible in placement if weather protection is managed. If you need a unit strictly for an indoor utility closet or basement, Product A is confirmed safe. If you are considering a garage or conditioned space, Product B’s slim profile offers space-saving benefits.
temperature control
Product A allows temperature adjustments from 95°F to 140°F with a precision of ±1°F. Product B offers a range from 86°F to 131°F in 1°F increments. Product A’s higher maximum temperature of 140°F is beneficial for filling large tubs or running high-demand appliances that need hotter water. Product B’s lower maximum may require mixing with cold water for certain uses. Both provide digital control for steady temperatures. If you need very hot water for specific tasks, Product A has the advantage. For standard shower and sink use, both ranges are sufficient.
dimensions and weight
Product B is more compact, measuring 13.7 × 11.42 × 3.54 inches and weighing 15.2 pounds. Product A is larger at 20.55 × 13.27 × 5.91 inches and weighs 19.2 pounds. Product B’s ultra-slim design saves more floor or wall space, making it ideal for tight spots. Product A is still relatively compact but takes up more room. If space is a primary concern, Product B is the better fit. Its smaller footprint allows for easier mounting in confined areas. Product A’s slightly larger size may require more planning for placement.
Which APUS Model Fits Your Home
Homeowners seeking propane reliability
Choose the propane model if you need grid independence. It delivers 95,000 BTU with a 4.42 GPM flow rate. The unit maintains temperature within ±1°F and operates quietly at 36dB. It includes intelligent freeze protection and runs on standard 120V AC power. This setup ensures steady hot water during power outages.
Users prioritizing space and efficiency
Select the electric model for its ultra-slim 3.54-inch depth. It achieves 99.8% thermal efficiency with self-modulating technology. The unit measures 13.7 inches high and weighs just 15.2 pounds. It offers precise digital control in 1°F increments and includes built-in memory to restore settings after power loss. Ideal for tight installation spaces.
Buyers needing high-temperature stability
The propane heater offers a wider temperature range from 95°F to 140°F. It uses smart CPU technology and high-precision sensors to prevent hot or cold shocks. This stability supports simultaneous use for two showers and a sink. The oxygen-free copper heat exchanger ensures durable performance and consistent output for demanding household schedules.
The products compared
APUS 95,000 BTU 4.42 GPM Indoor Propane Heater
Best for: Indoor high-flow hot water needs
- Fuel Type
- Propane
- Flow Rate
- 4.42 GPM
- BTU
- 95,000 BTU
- Installation Location
- Indoor
- Voltage
- 120 V
- Temperature Control
- 95°F–140°F, ±1°F
View on Amazon: APUS 95,000 BTU 4.42 GPM Indoor Propane Heater Affiliate link
This APUS propane tankless water heater delivers 95,000 BTU and a 4.42 GPM flow rate for indoor use. It features precise temperature control within ±1°F and an oxygen-free copper heat exchanger for 98% thermal efficiency. The unit operates quietly at 36dB and includes built-in freeze protection. It suits households needing steady hot water for multiple fixtures without the bulk of a traditional tank.
Pros
- 95,000 BTU heating capacity with 4.42 GPM flow
- Temperature stability within ±1°F of set point
- 98% thermal efficiency with oxygen-free copper heat exchanger
- Quiet operation at 36dB
Cons
- Indoor installation only
- Requires 120V AC power connection
- 2-year warranty coverage
Good fit if
- You need high flow for simultaneous shower use
- You want precise temperature control within ±1°F
- You have indoor space for installation
Skip if
- You require outdoor installation
- You need natural gas fuel type
- You prefer longer than 2-year warranty
Verdict: APUS Propane 95k BTU Tankless Heater provides reliable high-flow hot water with precise temperature stability for indoor households. It fits users who prioritize steady performance and efficiency over outdoor versatility or extended warranty terms.
APUS 18kW 4.4 GPM Tankless Water Heater
Best for: tight spaces with 240V power access
- Fuel Type
- Electric
- Flow Rate
- Up to 4.4 GPM
- Wattage
- 18 kW
- Installation Location
- Indoor
- Voltage
- 240V
- Temperature Control
- 86°F–131°F, 1°F increments
View on Amazon: APUS 18kW 4.4 GPM Tankless Water Heater Affiliate link
The APUS 18kW unit delivers up to 4.4 GPM of hot water using 240V power. Its ultra-slim 13.7-inch height and 15.2-pound weight allow for wall mounting in tight spaces. You get precise digital control with 1°F increments and 99.8% thermal efficiency. This model suits whole-house or point-of-use installations where electric power is available.
Pros
- High thermal efficiency of 99.8% reduces standby heat loss
- Slim profile measuring 13.7 x 11.42 x 3.54 inches saves space
- Precise temperature control from 86°F to 131°F in 1°F increments
- Built-in memory restores preferred settings after power outages
Cons
- Requires professional installation with 240V, two 40A breakers, and 8 AWG wire
- Limited to electric power, not suitable for gas-only setups
- Flow rate of 4.4 GPM may struggle with multiple high-demand fixtures
Good fit if
- You need a compact unit for tight wall spaces
- You have existing 240V electrical infrastructure
- You want precise temperature adjustments for sensitive skin
Skip if
- You only have gas lines and no 240V circuit
- You need to run more than three fixtures simultaneously
- You prefer DIY installation without professional electricians
Verdict: APUS 18kW Electric Tankless Heater fits homeowners with 240V power who value space-saving design and precise temperature control. It works well for single-bathroom or point-of-use applications where high flow rates are not critical.
Specifications side by side
| Spec | APUS 95,000 BTU 4.42 GPM Indoor Propane Heater | APUS 18kW 4.4 GPM Tankless Water Heater |
|---|---|---|
| Fuel Type | Propane | Electric |
| Flow Rate | 4.42 GPM | Up to 4.4 GPM |
| BTU | 95,000 BTU | not stated |
| Wattage | not stated | 18 kW |
| Installation Location | Indoor | Indoor |
| Voltage | 120 V | 240V |
| Temperature Control | 95°F–140°F, ±1°F | 86°F–131°F, 1°F increments |
| Dimensions | 20.55 x 13.27 x 5.91 in | 13.7 × 11.42 × 3.54 in |
| Weight | 19.2 pounds | 15.2 pounds |
| Color | Propane Gas,4.42GPM,95,000BTU，Space Gray | Gray |
| Model | AP-AWH-Q13LPG | AP-ADSK180-H18 |
Frequently asked questions
Can the APUS propane heater be installed outdoors?
No. The APUS 95,000 BTU Propane Heater is designed for indoor installation only. You must place it in a protected area to prevent weather damage. The electric 18kW model is also typically used indoors or in covered spaces, but the propane unit strictly requires an indoor setting for safe operation and proper ventilation.
Which unit is smaller in size?
The APUS 18kW Electric Heater is more compact. It measures 11.4 inches wide and 13.7 inches high. The propane model is taller and narrower, standing 20.6 inches high with a 5.9-inch width. If you have limited vertical space, the electric unit fits tighter. The propane unit is also slightly heavier at 19.2 pounds versus 15.2 pounds.
Do both heaters provide the same flow rate?
Yes, they offer nearly identical flow rates. The propane model delivers 4.42 GPM. The electric 18kW unit provides 4.4 GPM. This means both can supply hot water for a single bathroom or point-of-use application effectively. The difference is negligible for most household needs, allowing you to choose based on fuel type rather than flow performance.
What power source does each heater require?
The first model runs on propane gas. It does not need a dedicated electrical circuit for heating, though it may need power for controls. The second model requires a 240V electrical connection and uses 18 kW of wattage. You must ensure your home has the necessary electrical capacity for the electric unit before purchasing.
Is one model better for tight spaces?
The APUS 18kW Electric Heater is better for tight spaces. Its compact design fits well in small utility closets or under sinks. The propane model is taller, which might limit placement options. If your installation area has height restrictions, the electric unit is the more practical choice for space-saving design.
What are the physical dimensions of the propane heater?
The APUS Propane Heater measures 5.9 inches in width, 5.9 inches in length, and 20.6 inches in height. It weighs 19.2 pounds. The color option is space gray. These dimensions help you plan the mounting location. Ensure you have at least 21 inches of vertical clearance for safe installation and maintenance access.