Upgrading to a tankless water heater in your RV is one of the smartest moves for comfort, efficiency, and endless hot showers on the road. If you’re tired of waiting for your tiny RV tank to recover—or just want to save space and energy—this complete guide will walk you through the installation process, key safety tips, the best products, and everything you need to know before you start.
Quick Picks: Best Tankless Water Heaters for RV Installation
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Best Overall:
Girard 2GWHAM On-Demand Tankless Water Heater – RV-specific design, reliable, and efficient. -
Best Premium:
Furrion 2.4GPM RV Tankless Gas Water Heater – Digital controls, modern safety features, and high flow rate. -
Best Budget:
Camplux 2.64 GPM Portable Propane Tankless Water Heater – Great for outdoor or seasonal RV use.
Buyer’s Guide: Choosing the Right Tankless Water Heater for Your RV
- Fit & Cutout Size: Check the size of your existing tank water heater. Many tankless RV heaters are designed as direct replacements, but always measure your compartment first.
- Power Source: Most RV tankless water heaters use propane with a 12V ignition/control system. Some portable models only need propane.
- GPM (Gallons Per Minute): Look for 1.5–2.5 GPM minimum. More GPM means you can run a shower and sink at once.
- Freeze Protection: If you camp in cold climates, choose a model with built-in freeze protection.
- Controls & Display: Digital controls let you set your temperature and monitor operation for safe, steady hot water.
- Noise Level: Modern models run quietly—great for light sleepers.
- Warranty & Support: Stick with well-reviewed brands that offer strong support and clear documentation.
What You’ll Need: Tools & Supplies
- New tankless RV water heater
- Philips and flathead screwdrivers
- Adjustable wrench or socket set
- Pipe thread sealant or Teflon tape
- Pliers and wire strippers
- Drill and bits (for new mounting holes, if needed)
- RV-compatible caulk/sealant
- Propane leak detector solution (or soapy water)
- Wire connectors (if connecting to 12V power)
- Manual for both your old and new water heater
- Clean rags, gloves, and a flashlight
Step-by-Step: How to Install a Tankless Water Heater in an RV
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Turn Off All Power and Gas
Shut off your RV’s propane supply and disconnect from shore power and batteries. Safety first! -
Drain and Remove the Old Water Heater
Open the drain valve and remove the water heater access panel. Disconnect water lines, propane line, and any electrical connections. Remove mounting screws and slide out the old tank. -
Prep the Opening
Clean the cutout and check for any sharp edges or old sealant. Dry-fit the new tankless heater to ensure it fits. Adjust the opening if needed. -
Install the New Tankless Heater
Slide the new unit into place. Line up the mounting holes, or mark and drill new ones if necessary. Secure with screws and seal around the edges with RV caulk to prevent leaks. -
Connect Water Lines
Attach hot and cold water lines using Teflon tape or thread sealant. Tighten connections but avoid overtightening. -
Connect Propane Line
Attach the propane line, using two wrenches to avoid twisting. Check the connection with leak detector solution after turning gas back on. -
Wire 12V Power (if required)
Splice and connect the power wires per your heater’s instructions, using crimp connectors or wire nuts. Double-check polarity and fuse ratings. -
Test for Leaks and Secure Connections
Turn water and gas back on. Look for leaks at every joint—fix any before proceeding. -
Prime and Test the Water Heater
Open a hot water tap to fill the heater and remove air. Turn on power, follow the startup procedure, and test for hot water and proper operation. -
Seal and Finish
Apply a final bead of sealant around the exterior, replace any access covers, and clean up your workspace.
Tip: Always read your new heater’s manual and double-check all safety steps. If unsure, hire a certified RV technician to complete installation.
Best RV Tankless Water Heaters: Reviews
Girard 2GWHAM On-Demand Tankless Water Heater
- RV-specific design—fits most Suburban/Atwood cutouts
- 2.4 GPM—ideal for showers and sinks at once
- Low 12V power draw, works off-grid
- Integrated freeze protection
- Quiet, reliable, and efficient
Final Verdict: The best all-around RV tankless water heater for most travelers.
See it on Amazon
Furrion 2.4GPM RV Tankless Gas Water Heater
- Digital temperature controls
- 2.4 GPM, fast hot water delivery
- Multiple safety features and winterization mode
- Modern look, quiet, and road-tested durability
Final Verdict: Best for those wanting advanced features and luxury hot water in their RV.
Check price on Amazon
Camplux 2.64 GPM Portable Propane Tankless Water Heater
- Great for outdoor showers, cabins, or temporary installs
- Easy hook-up—no wiring required
- Affordable, portable, and versatile
- 2.64 GPM, strong hot water flow
Final Verdict: The top pick for budget buyers and those needing a simple, seasonal solution.
See details on Amazon
Comparison Table: Top Tankless Water Heaters for RVs
| Model | GPM | Power | Freeze Protection | Digital Control | Best For | Price Link |
|---|---|---|---|---|---|---|
| Girard 2GWHAM | 2.4 | Propane/12V | Yes | No | All-around RV, direct replacement | View |
| Furrion 2.4GPM | 2.4 | Propane/12V | Yes | Yes | Luxury RV, digital control | View |
| Camplux 2.64GPM | 2.64 | Propane | No | No | Portable/outdoor use | View |
FAQ: Installing a Tankless Water Heater in an RV
- Can I install a tankless water heater myself?
Many RVers do, but always follow your model’s manual. If you’re not confident with gas or electrical work, hire a professional for safety. - Will a tankless heater work in winter?
Yes, if your unit has built-in freeze protection and your RV is properly winterized. - Is it really endless hot water?
Yes, as long as you have propane, water, and 12V power available—no more waiting for a tank to heat up! - Can I replace my old tank heater with tankless?
In most cases, yes. Check cutout sizes and power/gas compatibility before purchasing. - How do I maintain my RV tankless water heater?
Flush the heater annually to prevent mineral buildup, and check connections for leaks regularly.
Conclusion
Upgrading to a tankless water heater in your RV is a game-changer for road comfort, space savings, and energy efficiency. With the right model and this step-by-step guide, you’ll enjoy instant, endless hot water wherever you roam. Choose one of the top heaters above, follow safe installation practices, and make every RV trip more comfortable and convenient!