120,000 BTU vs 68,000 BTU Tankless Water Heaters: Which Should You Buy?
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The 120000 btu vs 68000 btu tankless water heater debate centers on your hot water needs. Both units use propane fuel and provide on-demand heating. The primary difference lies in their output capacity and intended environment. One model delivers higher flow rates for indoor home use, while the other is compact and designed specifically for recreational vehicles. Your choice depends on whether you need residential power or portable RV compatibility.
Key differences
| Aspect | APUS 5.43 GPM Propane Tankless Water Heater | APUS 68,000 BTU RV Propane Water Heater |
|---|---|---|
| BTU Output | 120,000 BTU | 68,000 BTU |
| Flow Rate | 5.43 GPM | 3.9 GPM |
| Voltage | 120V AC | 12V DC |
| Installation Location | Indoor | RV Compartment |
| Dimensions | 20.55 x 13.27 x 5.91 in | 14.96 x 14.96 x 14.18 in |
Which one should you choose?
Choose APUS 5.43 GPM Propane Tankless Water Heater if
- You need to run multiple fixtures simultaneously in a home.
- You have standard 120V AC electrical access.
- You want higher flow rates for longer showers.
Choose APUS 68,000 BTU RV Propane Water Heater if
- You are replacing a tank heater in an RV.
- Your power source is 12V DC.
- You need a unit that fits standard RV cutouts.
Verdict: Choose the 120,000 BTU model if you require higher capacity for household use with standard home electricity. Select the 68,000 BTU unit if you are upgrading an RV and need compact dimensions with 12V DC power. Both provide propane efficiency tailored to their specific environments.
120k vs 68k BTU Comparison
Heating capacity
Product A delivers 120,000 BTU of heating power, supporting up to 5.43 GPM for three to four water points. This high output suits larger homes or multi-person households needing simultaneous hot water. Product B provides 68,000 BTU, yielding 3.9 GPM. This capacity is designed for RVs and smaller spaces, replacing traditional tank heaters. The higher BTU in Product A ensures robust performance for demanding indoor use, while Product B offers sufficient heat for compact mobile living. You should choose based on your household size and water demand.
Flow rate
Product A achieves a flow rate of 5.43 GPM, allowing multiple fixtures to run concurrently without significant temperature drops. It also features a low-flow start of 0.66 GPM for efficiency. Product B offers 3.9 GPM, which is adequate for single-point RV use or a shower and sink combination. It starts at 0.55 GPM. The higher flow rate in Product A makes it better for homes with high water usage. Product B’s lower flow is optimized for the limited plumbing systems found in travel trailers and campers.
Installation location
Product A is designed for indoor installation, measuring 20.55 x 13.27 x 5.91 inches. Its compact wall-mounted design preserves floor space in homes and rentals. Product B fits standard RV water heater openings, with dimensions of 14.96 x 14.96 x 14.18 inches and a 12.6 x 12.6 inch cutout. It replaces Suburban and Atwood tanks in campers. Product A suits fixed residential settings, while Product B is built for the confined, standardized compartments of mobile RVs. Your vehicle or home type dictates the correct form factor.
Voltage requirements
Product A requires 120V AC power for its controls and LED touchscreen. This standard household voltage is common in homes but not in RVs. Product B operates on 12V DC power, compatible with standard RV electrical systems. This allows it to function off-grid or while plugged into a trailer’s battery system. If you are installing in a home, Product A’s voltage is suitable. For RVs, Product B’s 12V DC compatibility is essential for proper operation and integration with existing mobile power sources.
Temperature control
Product A offers precise ±1°F control with a range of 95–149°F, managed by high-precision sensors and a smart CPU. The LED touchscreen displays the selected setting clearly. Product B maintains temperatures between 95–124°F using intelligent staged combustion that adjusts to incoming water conditions. It lacks a mentioned touchscreen but includes a remote control for adjustment. Product A provides finer granularity and a wider max temperature, ideal for specific home needs. Product B’s remote offers convenience in tight RV spaces.
Safety features
Product A includes anti-freeze protection activating near 41°F and multi-layer shutdowns for abnormal conditions. It comes with 2-year coverage. Product B features CSA certification, flame failure, gas leak, dry-burn, and over-temperature protection, plus a 203 PSI pressure relief valve. It activates freeze protection at 35.6°F. Both units prioritize safety. Product B’s CSA certification and extensive sensor suite are tailored for RV safety standards. Product A’s protections are robust for indoor residential use. Both offer reliable automatic shut-offs for peace of mind.
Choose the right unit for your space
Homeowner with multiple bathrooms
You need higher capacity for simultaneous use. This model delivers 5.43 GPM at 120,000 BTU, supporting three to four water points. The 120V AC power and indoor design fit standard home installations. It maintains temperature within ±1°F, ensuring consistent hot water for showers and sinks during peak usage times.
RV owner seeking replacement
This unit fits standard RV water heater openings with a 14.96-inch square footprint. It runs on 12V DC power, matching your vehicle’s electrical system. The 68,000 BTU output provides 3.9 GPM, sufficient for single-point RV use. CSA certification and remote control add safety and convenience for mobile living.
Traveler needing compact heating
You require a lightweight, space-saving solution for travel. Weighing 24 pounds, this heater replaces bulky tank units. It operates reliably up to 9,800 feet elevation. The intelligent freeze protection activates at 35.6°F, safeguarding the unit during cold-weather camping. Its compact size ensures easy storage and installation in tight compartments.
Quick picks
| # | Product | Best for | Price |
|---|---|---|---|
| 1 | APUS 5.43 GPM Propane Tankless Water Heater | large indoor homes needing high flow | Check price of APUS 5.43 GPM Propane Tankless Water Heater on Amazon |
| 2 | APUS 68,000 BTU RV Propane Water Heater | Standard RV water heater replacements | Check price of APUS 68,000 BTU RV Propane Water Heater on Amazon |
The products compared
APUS 5.43 GPM Propane Tankless Water Heater
Best for: large indoor homes needing high flow
- BTU
- 120,000 BTU (what this guide is about)
- Fuel Type
- Propane
- Flow Rate
- 5.43 GPM
- Installation Location
- Indoor
- Voltage
- 120V AC
- Temperature Control
- 95–149°F, ±1°F
View on Amazon: APUS 5.43 GPM Propane Tankless Water Heater Affiliate link
This APUS propane unit delivers 120,000 BTU and 5.43 GPM for indoor use. It supports three to four water points with precise ±1°F temperature control. The oxygen-free copper heat exchanger offers high efficiency. Its compact wall-mounted design saves space. Standard 120V AC power runs the controls. This model suits larger homes needing high flow rates.
Pros
- 120,000 BTU output for high demand
- 5.43 GPM flow rate for multiple fixtures
- ±1°F temperature precision with LED display
- Oxygen-free copper heat exchanger for efficiency
- Indoor installation with compact wall-mount design
Cons
- Indoor installation requires venting
- Heavier build at 19.2 pounds
- 2-year warranty is shorter than industry standard
Good fit if
- You need high flow for multiple bathrooms
- You want precise temperature control
- You have indoor space for wall mounting
Skip if
- You require outdoor installation only
- You need natural gas instead of propane
- You prefer a lighter portable unit
Verdict: APUS 120k BTU Propane Tankless Heater delivers strong performance for large households. It fits homes needing high flow and precise heat. Choose this if you have indoor space and propane access.
APUS 68,000 BTU RV Propane Water Heater
Best for: Standard RV water heater replacements
- BTU
- 68,000 BTU (what this guide is about)
- Fuel Type
- Propane
- Flow Rate
- 3.9 GPM
- 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 tankless water heater delivers 68,000 BTU of propane power for RV use. It provides up to 3.9 GPM of hot water, starting at a low 0.55 GPM flow. The unit fits standard 12.6 x 12.6 inch RV openings. It operates on 12V DC and includes a remote control. CSA certification ensures safety for travel and camping.
Pros
- 68,000 BTU propane burner for on-demand hot water
- 3.9 GPM flow rate with 0.55 GPM start
- Fits standard 12.6 x 12.6 inch RV cutouts
- Includes remote control for temperature adjustment
- CSA certified with intelligent freeze protection
Cons
- Lower 68,000 BTU output compared to 120,000 BTU models
- Smaller 3.9 GPM flow rate limits simultaneous use
- Heavier 24-pound build requires sturdy mounting
Good fit if
- You need a direct replacement for standard 6-12 gallon RV tanks
- You camp at elevations up to 9,800 feet
- You want remote temperature control inside your RV
Skip if
- You require high flow rates for multiple showers
- You need indoor residential installation
- You prefer a lighter unit under 20 pounds
Verdict: APUS 68,000 BTU RV Propane Heater is ideal for RVers replacing standard tank heaters who prioritize compact fit and remote convenience. It suits those with lower hot water demands rather than high-flow needs.
Specifications side by side
| Spec | APUS 5.43 GPM Propane Tankless Water Heater | APUS 68,000 BTU RV Propane Water Heater |
|---|---|---|
| Fuel Type | Propane | Propane |
| Flow Rate | 5.43 GPM | 3.9 GPM |
| BTU | 120,000 BTU | 68,000 BTU |
| Installation Location | Indoor | not stated |
| Voltage | 120V AC | 12V DC |
| Temperature Control | 95–149°F, ±1°F | not stated |
| Certification | not stated | CSA |
| Dimensions | 20.55 x 13.27 x 5.91 inches | 14.96 x 14.96 x 14.18 inches |
| Use | not stated | RV |
| Weight | 19.2 pounds | 24 pounds |
| Color | Space Gray | White |
| Model | AP-AWH-Q16LPG | AP-AWH-RV10W-NEW |
Frequently asked questions
Can I install a 120,000 BTU tankless water heater outdoors?
No. The 120,000 BTU APUS model is designed for indoor installation only. Its specific construction requires a protected environment. You must place it inside your home. This unit is not rated for outdoor exposure. Ensure you have adequate indoor space and proper ventilation for propane use.
What is the size difference between the 120k and 68k units?
The 120,000 BTU unit is significantly larger. It measures 19.3 inches wide and 27.6 inches high. The 68,000 BTU RV model is much more compact. It stands 15 inches high and is 14.2 inches wide. The smaller unit weighs more at 24 pounds compared to 19.2 pounds for the larger model.
Does the 68,000 BTU heater work for a full house?
It is not ideal for a full house. This 68,000 BTU unit is built for RV replacements. It has lower hot water demands. It suits travelers who need compact fit and remote convenience. Large homes needing simultaneous hot water for multiple bathrooms should choose the higher capacity 120,000 BTU option instead.
What fuel do both tankless water heaters use?
Both models run on propane. The 120,000 BTU heater uses propane for indoor heating. The 68,000 BTU heater also uses propane fuel. You need a propane supply for either unit. Both provide on-demand heating without storing water. Ensure your propane lines match the requirements for your specific installation location.
Which unit is better for an RV?
The 68,000 BTU model is the better choice. It is specifically designed as an RV replacement. Its compact dimensions fit standard RV spaces. It offers remote convenience for mobile living. The 120,000 BTU unit is too large and intended for indoor home use. Stick with the smaller unit for your vehicle.
How many gallons per minute does the 120k unit provide?
The 120,000 BTU APUS heater delivers 5.43 GPM. This flow rate supports three to four water points simultaneously. It is suitable for large households with high demand. The higher BTU output ensures consistent heating at this flow rate. You get strong performance for large indoor homes needing high flow.