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RV Tankless Water Heater with Mixing Tank
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View price-protection termsInstaShower Ultra combines 66,000 BTU output, up to 3.9 GPM flow and a built-in mixing tank designed to reduce cold-water interruption. Segmented combustion targets steady outlet temperature.
View all features ↓Best for high-demand travel, colder inlet water and customers prioritizing the strongest flow plus mixing-tank comfort.
BACKED BY FOGATTI
Official WarrantyAutomatically activated with your direct order.2-year warranty · Original parts included
Reference valueYour appliance, its original components and all original accessories included with your purchase are covered against defects in materials and workmanship.
2-year warranty
Your direct order is your proof of purchase. Use your order number for warranty support—no registration form needed.
Direct orders receive priority for the newest available production batches for the selected model, color and fulfillment location. Product refinements may vary by batch; new features are not guaranteed.
Coverage period, exclusions, labor and shipping terms depend on your model. Review the full warranty terms before purchase.
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Gas, water and electrical connection materials vary by RV.
Which exterior door is included?
Includes the white 15 × 15-inch exterior access door for matching openings and trim coverage.
What does the mixing tank do?
It buffers and blends water to reduce brief cold-water interruption when shower flow changes.
Does it need 120V power?
Controls and ignition use 12V DC; the burner uses LP propane. No 120V supply is required.
Pair the water-heater upgrade with climate equipment matched to the RV roof and duct layout.
Add quiet rooftop cooling and heat-pump warmth with a standard non-ducted roof opening and 115V supply.
Check roof fit and optionsAdd stronger propane heat through a furnace matched to the RV cabinet and central duct system.
Check furnace fit and options
This InstaShower Ultra package combines 66,000 BTU, up to 3.9 GPM, a built-in mixing tank and a ±1°F target with the included white 15 × 15-inch exterior door.
Ultra is not only a larger burner. Its water path and staged combustion are designed around temperature stability during real use.
The internal pre-mix system blends water before it leaves the heater, reducing the brief cold interruption that can happen in an RV plumbing loop.
Lower flame staging helps reduce overheating in warm conditions, while the full burner supports colder inlet water and higher demand.
Ultra provides the strongest flow platform in the range, with delivered flow shaped by inlet-water temperature and temperature rise.
Correct propane, ventilation, 12V power and winterization remain essential for safe operation.
This package combines the highest-flow Fogatti platform with a white 15 × 15-inch door for matching exterior openings.
The 3.9 GPM platform adds more headroom for couples and families who use hot water often.
It is designed to reduce cold-water interruption when the shower stops and restarts.
The white 15 × 15-inch door combines the finish with matching exterior coverage for the RV opening.
Includes the white 15 × 15-inch exterior access door for matching wall openings and trim coverage.
Includes the white 15 × 15-inch exterior access door for matching openings and trim coverage.
| Item | With Door | Without Door |
|---|---|---|
| Gas Water Heater × 1 | ✓ | ✓ |
| Installation and Operation Manual × 1 | ✓ | ✓ |
| Controller × 1 | ✓ | ✓ |
| Screw (ST5 × 25) × 12 | ✓ | ✓ |
| Screw (ST4 × 16) × 2 | ✓ | ✓ |
| Screw (M4 × 8) × 10 | — | ✓ |
| Screw (M4 × 6) × 4 | — | ✓ |
| Insulation Strip × 1 | ✓ | ✓ |
| Waterproof Sealing Strip (EPDM) × 1 | ✓ | ✓ |
Choose Ultra for the 3.9 GPM platform and mixing tank with the included white 15 × 15-inch door.
For maximum flow, tighter control and a measured 15 × 15-inch white-door replacement.
For regular shower use, up to 3.1 GPM and a ±1°F stability target.
For continuous hot water and everyday midsize-RV shower demand.
Mixing-tank operation, full retrofit and owner performance in three practical videos.
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A complete installation walkthrough covering the opening, connections and first hot water.
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An internal look at the parts designed to improve shower stability and service access.
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A practical review focused on cold-water interruption and shower consistency.
What owners say
Overall rating: 4.6944447 / 5 from 36 reviews.
The Fogatti InstaShower Ultra RV tankless water heater offers high-quality performance with a 66,000 BTU capacity, providing instant hot water at up to 3.9 GPM. Its advanced heat exchange system and HydroShield-Tech ensure reliability even in extreme weather conditions. The unit is easy to install and includes a 150 PSI pressure relief valve, enhancing convenience and safety for RV users.
Review topics: [].
"there is very bad customer service . I ordered a unit with a gray door they sent me one without a door and said this is what i ordered and the door i need is out of stock. so at this point i just want to return it. I was told that i have to pay the cost of shipping for there mistake not happy"
"work good however the round edges on the outer ring didnt cover the 18"x18" hole. would have worked better if the corners were squared off."
"I easily installed this in my 2022 Airsteam Caravel 22FB. It just took a couple minor changes to the water lines. We boondock and this is the heater we needed to conserve water when showering. We can now take Navy showers without getting 30 seconds of cold water when turning the shower back on. . The water temp with the Ultra briefly drops from 120 to 100 for several seconds then back to 120 . We look forward to enjoying the new Ultra heater!"
"We replaced the Girard tankless water heater in our 2024 Cougar 260MLE earlier this year. My wife was not happy with the performance of the Girard from day 1; and was ready to go back to a tanked water heater when we saw some reviews of the InstaShower Ultra. Since installing the new heater; we haven't had 1 cold shower; and temp stays steady; even if another faucet is turned on. Very easy install; and we are very satisfied. I was able to paint the door black to match the furnace door on the unit."
"After suffering for two years attempting to use the factory installed water heater on my 2024. 5 Airstream Globetrotter; I have huge expectations of the Fogatti InstaShower Ultra I just purchased. However; I'm not sure we have gotten off on the right foot. I took the unit in the unopened box to Vinnie's in Tallahassee for installation. After dropping my trailer off; l almost immediately received a text with pictures from Vinnie's indicating the frame was bent and saying if they had purchased the unit themselves they would request a new frame. I did not have the time in my schedule to request a new frame from Fogatti. The pros at Vinnie's; nonetheless; did a nice job manipulating the frame until it is only noticeable by them and me. I have used the unit now for a couple of days while on my return trip home. I am happy to report the water heater seems to be working well. With my prior history of dealing with a faulty water heater; I have all fingers crossed and praying that the Fogatti unit delivers. If for some reason the frame fails; I will expect Fogatti to replace it at no charge."
"The build quality is excellent. The hookup amd fittment were simple and it operates perfectly. Thanks Fogati."
"I have a 2026 No Boundaries (Forest River) NoBo 20. 3 Beast Mode. It came with a stock Suburban ST42 Tankless Unit. I had to use the Suburban wall controller to somewhat maintain a constant water temperature. If I ever mixed or introduced a tiny bit of cold water; or turned on another fixture; the Suburban Unit would shut off and quit producing Hot Water. And their controller has the Loudest Beep each time you move the water 1 degree. Very annoying. Not my idea of Fun. Now let's look at the Fogatti Ultra. I'll start off with a WoW! So Happy I purchased the Ultra. All Pros. No Cons at all. The controller Beep Sound is very nice and quiet. I saw reviews where People wished the wire didn't come out of the bottom of the controller. Well guess what? The controller pops open and there is a white silicone plug that the wire can be routed thru for a professional looking installation. Let's move on. The Unit was a perfect fit to replace the Suburban (Did not use or need Fogotti Trim). Installation was so easy. I wish the Unit was Black instead of Grey; so I painted the Cover with Black Truck Bed Liner Rust oleum Paint. I can now set my Fogotti Water Controller to the Hottest Temp I want and leave it. I now can shower; do dishes in kitchen; and run sink in bathroom or outside sprayer all at the same time and it keeps heating with just the tiniest temp change for a split second. My water flow can drop way down; and it keeps heating. Also; the hinges on door are on the forward side and a nice secure latch. Now this is my idea of FUN! 8o) Great Job Fogotti. No more cold water surprises."
"On my first trip with the instashower ultra in a 2026 Surveyor Legend 252 RBLE. It was an easy install - went right in where the old one came out. The results are excellent. It solved every single problem we had with the original tankless unit. Dry camping is night and day more pleasant when it comes to showers."
"We were able to have Rocky Mountain RV repair in Sedalia, CO install our InstaShower Ultra and we used it for a week. Rocky Mountain RV has installed many Fogatti water heaters but they were surprised to see our Ultra when we had them install it. They were very impressed with this Top of the Line model. They had no issues with the installation and they liked the quality of the heat system. After a weeks use we are sorting out our use procedures and getting accustomed to an instant hot water system. I m crediting our installer s comments because at this point they have a lot more experience with water heaters and Fogatti than we do so it s impressive that they have confidence in their installation and the Ultra heater."
"Is it perfect, no, but after 4 days using it, it s pretty darn close. It definitely beats the Furrion it replaced. It fit perfectly in the hole where my Furrion was installed in, inside my 2022 Reflection. Connections were a breeze, hot line, cold line, propane and electrical. Make sure you re sure of your wire colors. Installed the thermostat, but I m not sure the reason for it having a cradle, vs. a permanent mount. Turned on the unit, set the temp and after 15-20 seconds warm water. Another 20-30 seconds nice hot water. My only issue so far is that the water will at times cycle from hot to warm as I take a shower, which while not annoying, is noticeable. Now let s see if it will survive a Michigan winter after being properly winterized. So far I ve had 3 Furrion s not survive, including after having a RV dealership, who shall not be named, General, supposedly properly winterize the rig. I figure I can t do worse. I ll update in the spring."
FAQs
See how the included 15 × 15-inch white door, 3.9 GPM platform and utility setup support the upgrade.
Choose the white 15 × 15-inch package above. Review the installation guide before ordering.
