Feelrogast Electric Tank Water Heater-8 Gallon Under Sink Instant Hot Water for RV, Camper, Kitchen, Food Truck, 120V 1500W, Wall or Floor Mounted

Why I tried this mini-tank heater

I needed reliable, near‑instant hot water at a couple of “difficult” locations: a garage sink that’s far from the main water heater and an RV galley where a tankless unit struggled with fluctuating flow. A compact, point‑of‑use tank made more sense than a small tankless because it eliminates the cold‑water slug and doesn’t care about minimum flow rates. That’s how I ended up installing the Feelrogast 8‑gallon mini‑tank heater under a sink and later moving a second unit into an RV.

Installation: straightforward if you plan the basics

The unit is designed to mount on a wall or sit on the floor of a cabinet. I tried both orientations. Wall mounting was clean and opened up floor space, but remember that 8 gallons of water adds about 66 pounds on top of the heater’s own weight, so use proper anchors into studs or a solid backer.

A few install notes from my experience:
- Plumbing: The water connections are standard 1/2" NPT. I used braided stainless supply lines with pipe thread adapters and sealed the threads with PTFE tape. Keep the runs short for best “instant” effect.
- Electrical: It’s a 110/120V, roughly 1440–1500W unit. A dedicated 20‑amp breaker is recommended. I put it on a GFCI‑protected circuit because it’s under a sink—good practice for wet locations.
- Safety discharge: The tank is rated for up to 109 PSI. Ensure your T&P discharge line routes to a safe drain or an appropriate catch. If your home pressure is high or you see expansion‑related dripping, consider a small expansion tank on the cold side.
- First start: I filled the unit completely before powering it, then flushed a couple of gallons to clear manufacturing residue. It’s standard practice, and it helped ensure clean water from day one.

The 44‑inch power cord was long enough for the cabinet I used, but it’s worth measuring your outlet position before you start cutting holes. There’s a simple indicator light on the front that shows when the unit is actively heating—handy during setup and troubleshooting.

Performance: quick heat, stable temps, and silent operation

This is a mini‑tank, not a tankless. “Instant” here means hot water is immediately available at the fixture once the tank is up to temperature and the short pipe run is purged. In practice:
- Initial heat‑up: From a cold tank, I saw roughly 25–35 minutes to reach typical sink temps, depending on the setpoint. The thermostat is adjustable from 86°F up to 167°F.
- Reheat: Recovery is impressively quick for a 120V unit. After drawing down part of the tank for dishwashing, I saw the heater catch back up fast enough that I never “ran out” during normal sink chores.
- Point‑of‑use feel: Under‑sink placement eliminates the line loss you get from a distant whole‑home heater. Hot water is effectively immediate at the faucet, which was the entire point for my garage sink and the RV galley.
- Showers: With 8 gallons, it can support a short, low‑flow shower in the right setup (especially if you temper to a higher setpoint and blend at the valve), but don’t expect long, hotel‑style showers. For sinks, it’s fantastic; for continuous bathing, it’s a compromise.
- Noise: It’s very quiet. The most you’ll notice is a faint click when heating starts or stops—no fan noise like many tankless units.

I kept the thermostat just below scalding territory and mixed at the tap to extend perceived capacity. If you have kids around, consider adding a mixing valve or keeping the setpoint more conservative.

Build quality and safety

Two components stood out to me:
- Heating element: The unit uses a 316 stainless steel element. That’s a good choice for corrosion resistance and longevity, especially if your water has a habit of chewing through lesser alloys.
- Tank: The tank is stainless with a relatively thick wall and an enamel coating (a double‑process enamel, according to the manufacturer). That combination is unusual at this price and should help resist rust and pinhole leaks.

On the safety side, there’s a high‑temp limit, automatic temperature control, and a leakage‑protection plug. Electrical insulation on the inlet/outlet is a nice touch. The heater carries CE/ROHS/FCC marks; while different regions treat certifications differently, it’s still reassuring to see a safety and materials trail. Heat retention is also solid—insulation feels robust, and the tank holds temperature well between cycles.

In the RV and the workshop

In the RV, the heater transformed the galley experience. Low-flow trickles don’t bother a tank heater the way they do many budget tankless units. I mounted it low in a cabinet, teed it into the cold feed, and secured the discharge safely. Short run to the faucet, instant hot water at the handle—no more wasting water waiting for heat to arrive.

In the workshop, where the sink is on a long run from the main house heater, the mini‑tank cut down waste dramatically. I used a switched outlet there, so I can power it up during work hours and shut it off later. With good insulation, it holds heat nicely between uses, and reheating is quick when I return.

Energy use and electrical considerations

At around 1440W, it’s comparable to a small space heater in terms of draw when heating. That’s very manageable on grid power, but it’s worth considering if you plan to run off a small inverter or a modest off‑grid solar setup. A dedicated 20‑amp breaker is a smart move for reliability, and the steady resistive load plays nicely with most home electrical systems.

If you want to optimize energy, a simple timer or switched outlet is an easy win: power it during known use windows and sleep it otherwise. Good insulation means the tank won’t lose heat rapidly.

Daily use: the small touches that matter

• Controls: The mechanical thermostat is simple and predictable. There’s no app, no display, and no learning curve—just a dial and a status light.
• Maintenance: I recommend a quick flush a few weeks after installation, then seasonally, especially in hard‑water areas. It keeps sediment from accumulating and helps maintain efficiency. If you’re on very hard water, a small inline filter or periodic descaling regimen will pay dividends.
• Fit and finish: The cabinet footprint is compact for an 8‑gallon tank, but it still demands realistic space. In very tight van or micro‑RV builds, a smaller capacity might fit better. For most under‑sink cabinets, it’s workable.

What could be better

• Space and weight: Eight gallons is a sweet spot for utility, but it’s not featherweight. Plan your mounting points and service clearances carefully.
• Power cord length: The 44‑inch cord is adequate, not generous. If your outlet is far, you’ll be relocating it or revising your cabinet layout.
• Not for all off‑grid setups: If you’re running a lean inverter or limited battery bank, the 120V/1500W draw may push you toward a propane or lower‑wattage alternative.
• No digital thermostat: A digital readout or tighter temperature granularity would be nice for some users, though the analog control works fine in practice.

Who it’s for

• RVs and campers that need dependable hot water without the quirks of budget tankless units
• Remote sinks (garage, office, salon station, outbuilding) where a long run wastes water and time
• Food trucks and mobile setups with standard 120V circuits and room for an 8‑gallon unit
• Home kitchens or bathrooms where the main heater is distant and “instant” matters

Who should look elsewhere

• Whole‑home coverage or long shower needs—this is a point‑of‑use solution
• Minimalist off‑grid systems that can’t comfortably spare 1440–1500W during heat cycles
• Ultra‑tight cabinets where even an 8‑gallon footprint is a squeeze

The bottom line

The Feelrogast 8‑gallon mini‑tank earns a spot on my short list of practical point‑of‑use heaters. It delivers fast, stable hot water at the faucet, has a well‑considered materials story (316 stainless element and enameled stainless tank), and the safety and installation details are dialed in: 1/2" NPT connectors, 120V operation, solid insulation, and a straightforward control scheme. Recovery is quick enough that day‑to‑day sink tasks never outran it, and it held temperature well between uses. Add in the simple installation and the flexibility to wall‑mount or floor‑mount, and it checks the right boxes.

Recommendation: I recommend this mini‑tank for anyone who needs reliable point‑of‑use hot water on a standard 120V circuit—especially RV owners, food truck operators, and homeowners with remote sinks. It’s not a whole‑home solution and it’s not ideal for lean off‑grid electrical systems, but for its intended use, it’s efficient, quiet, and confidence‑inspiring.