KINGRVER RV Hybrid Water Heater, 6 Gallon Tank, Electric & Gas Heating Options — Use Separately or Together for Faster Hot Water, Porcelain Lined Steel Tank with Direct Spark Ignition

Why I switched to a hybrid RV water heater

I replaced my aging RV water heater with the Kingrver hybrid heater earlier this season, and it’s been a meaningful upgrade in day-to-day use. The headline feature—being able to run propane, electricity, or both together—turns out to matter more than I expected. On hookups, I can lean on electric and save propane. Off-grid, I flip to gas. When I’m turning the rig over quickly between showers, I run both for faster recovery. That flexibility, paired with a steady 6‑gallon tank and simple preset controls, makes this unit feel well thought out for real RV use.

Installation and compatibility

The swap was straightforward. Kingrver sells the heater with optional 15" x 15" or 15" x 18" exterior doors, which covers the most common 4–6 gallon Suburban and Dometic cutouts. In my case, measurements lined up without needing to enlarge the opening. The footprint and connections are designed to match typical legacy installations, which helps keep the job within reach for a competent DIYer or any RV service shop.

A few practical notes from the install:
- Measure your cutout before ordering the door size; the 15" x 15" vs 15" x 18" choice matters.
- Plan your electrical hookup if you intend to use the electric element regularly; you’ll need shore power or a capable inverter.
- Propane connections were standard fare and the direct spark ignition integrated cleanly.

If you’re replacing a tankless unit, expect a bit more planning for framing and routing, but for most 4–6 gallon replacements, it’s a tidy upgrade path.

Build quality and design

The tank is porcelain‑lined steel, which is the right move for corrosion resistance in an RV environment. The door and trim feel solid and sealed up cleanly. Inside, the layout is uncluttered and serviceable. It’s not flashy, and I don’t need it to be—what matters is that it’s built to survive the jostling and temperature swings of travel.

Direct spark ignition is used for gas mode. In practice, it lights quickly and has been reliable for me. The electric element is, of course, silent. The burner produces the familiar soft roar during operation; it’s not obtrusive from inside the RV, and it shuts down cleanly.

Controls and daily use

The control scheme keeps it simple with three temperature presets: 104°F, 122°F, and 140°F. One‑touch selection is handy and eliminates the guesswork. I use 104°F for quick rinses or kids’ wash-ups, 122°F for general use, and 140°F when I want to stretch capacity by mixing with cold at the faucet.

Switching heating modes is equally straightforward—gas only, electric only, or the hybrid mode (both at once). If you’re accustomed to pokey recovery with gas or electric alone, the hybrid setting is the “get it done” button when everyone needs hot water back-to-back.

One trade‑off: there’s no granular temperature dial beyond the three presets. I didn’t miss it, but if you like fine control down to a degree, note the presets are the only options.

Performance: stable and predictable hot water

Compared with a tankless system I’ve used in the past, the 6‑gallon tank gives you consistency. There’s no “cold water sandwich” and no wrestling with faucet flow to keep a burner engaged. Water temperature is steady across short showers and dishwashing duty, and the tank absorbs usage spikes without sudden swings.

Recovery is where the hybrid setup shines. On electric only, it’s perfectly serviceable for routine use on hookups—showers, dishes, and handwashing spaced out through the day. On gas only, recovery is snappier and ideal off-grid. When I run gas and electric together, the tank is ready for another shower much sooner than either mode alone. For a family or for guests, that difference is noticeable.

To set expectations: this is not an endless hot water solution. Six gallons will comfortably cover short showers and intermittent use. If you space activities a bit—or preheat to 140°F and mix at the tap—you can stretch it further. If you want non-stop, hotel-style showers, a well‑sized tankless system at strong water flow is still the way to go, but then you trade away the tank’s stability and simplicity.

Energy use and modes

• Electric mode: Great on hookups; quiet and clean. It’s the mode I default to in campgrounds to save propane.
• Gas mode: Dependable off-grid heating. The direct spark ignition works as expected, and fuel use felt reasonable on multi-day trips.
• Hybrid mode: The recovery booster. I switch to this when back-to-back showers or dish cycles would otherwise outrun a 6‑gallon tank.

It’s a straightforward strategy: use electric when you can, gas when you need to, and both when you’re pressed for time.

Cold weather behavior

In shoulder-season camping with overnight lows around freezing, the heater kept pace without fuss, and hot water was ready each morning. The tank design helps here; stored hot water means you aren’t relying on an on-demand ignition and flow threshold at the moment you open the tap in cold conditions. As always, winterization practices still apply for hard freezes—this isn’t a substitute for proper RV winter prep.

Maintenance and longevity

Porcelain‑lined steel is a proven approach for tank longevity. I recommend:
- Flushing the tank periodically to remove sediment, especially after extended stays with hard water.
- Inspecting seals around the exterior door and replacing butyl/caulk as needed to keep the compartment dry.
- If your installation uses an anode rod (common on porcelain-lined tanks), check and replace it as it sacrifices over time.

These basics go a long way toward keeping recovery times strong and preventing premature corrosion.

What I liked

• Dual-fuel flexibility with a true hybrid mode makes the small tank punch above its weight.
• Stable, predictable temperatures—no surprises when someone flushes a toilet mid-shower.
• Simple preset controls at 104°F, 122°F, and 140°F fit real-world use and help manage scald risk.
• Straightforward installation with 15" x 15" and 15" x 18" door options for common cutouts.
• Porcelain‑lined steel tank feels built for the long haul.

Where it could be better

• Preset-only temperature control won’t please everyone who wants fine-tuning.
• Six gallons is still six gallons—you’ll want to space showers or use hybrid mode to keep up with heavy demand.
• Electric performance depends on having shore power or a capable inverter; hybrid mode will draw more current on AC.

Who it’s for

• RVers upgrading from an older 4–6 gallon unit who want faster recovery and modern controls without reworking the coach.
• Families who need reliable hot water for short showers, dish duty, and wash-ups throughout the day.
• Campers who mix boondocking and hookups and want to optimize fuel or power depending on the situation.
• Owners who prefer the temperature stability of a tank over the quirks of budget tankless heaters.

If your priority is limitless hot water and you have the plumbing, power, and consistent flow to support a high-output tankless system, you’ll likely lean in that direction. Everyone else will appreciate how “set-and-forget” this feels in daily camping life.

Recommendation

I recommend the Kingrver hybrid heater for RV owners who want a reliable, flexible upgrade that balances simplicity with performance. The combination of gas, electric, and hybrid modes, the steady behavior of a 6‑gallon tank, and the easy replacement path for common Suburban/Dometic cutouts make it a practical choice. It’s not designed to deliver endless showers, but it consistently delivers the kind of hot water RVers actually need—quick rinses, short showers, and steady temperature—without fuss. For most rigs and most trips, that’s exactly the point.