Bio Bidet A8 Serenity vs U770: Every Feature Compared

Today we’re comparing the Bio Bidet A8 Serenity with the Ultimate 770. The U770 is marketed as an advanced (semi-luxury) bidet while the A8 is supposed to be a full-on luxury option. IMO, neither quite rise to the level of luxury, but they both offer a lot of value for the money. 

For more in-depth info on the U770 (with images and demos), check out the Bio Bidet Ultimate 770 review article.

The Bio Bidet A8 Serenity is the better bidet, offering the best features of the Ultimate 770 and USPA 6800U. Compared to the U770, the A8 has a better water heater and convenience features like a double-sided LCD remote and auto function. 

Here’s a quick rundown of the differences: 

  • Water heater (hybrid vs advanced reservoir).
  • 3-in-1 vs 2-in-1 nozzle.
  • Turbo (high-pressure) mode.
  • Auto air deodorizer.
  • Aerated stream.
  • Different warranty lengths.
  • Fancier wireless remote.
  • Auto clean function.

Bio Bidet A8 vs Ultimate 770: Quick Comparison Table 

Feature(s)BB A8 SerenityBB Ultimate 770
Available in Elongated and RoundYY
Water Heater TypeAdvanced Hybrid-Type HeaterAdvanced Reservoir-Type Heater
Warm Air Dryer w/Adjustable TempYY
Heated Seat w/Adjustable TempYY
Handheld RemoteDouble-Sided Wireless Remote w/LCD ScreenSleek Wireless Remote
Air DeodorizerYN
Wand MaterialStainless SteelStainless Steel
Nozzle Design for Posterior and Front Feminine HygieneSingle 2-in-1 NozzleSingle 3-in-1 Nozzle
Adjustable Nozzle Position for Accurate Aiming5 Positions5 Positions
Wand Self-Clean FunctionOn-Demand Self-CleaningOn-Demand Self-Cleaning
Child Wash Mode
User Presets
(Save Your Preferred Settings)
2 Users; Front and Rear; Save Nozzle Position and Water Pressure2 Users; Front and Rear; Save Nozzle Position, Water Pressure, Water Temp, Seat Temp, and Dry Temp
Easy Auto Function
(One-Push Operation)
Bowl-Illuminating Night LightYY
Adjustable Water Temperature and PressureYY
High-Pressure Turbo ButtonNY
Water Pressure
(Flow Rate)
0.7 L/min or ~0.18 gal/min0.8 L/min or ~0.21 gal/min
Nozzle Oscillation
(Back-and-Forth Spraying)
MassageY Y
Aerated Wash YN
Slow-Close Seat/LidYY
Quick-Release Seat/LidYY
Power-Saving Eco Mode(s)YY
Aesthetic Low-Profile Design (Solid White, Few Decals, Etc.)YY
Safety Seat SensorYY

Main Differences: Bio Bidet A8 vs 770 

Different Water Heating Technology (A8 Is Better) 

First, is the water heater. The A8 has a hybrid heater while the U770 has an advanced reservoir (or above-average tank-type) heater. 

The short version: both bidets have heaters that provide endless heated water. The A8 has an advanced hybrid heater that provides warmer water for longer. The U770 has an enhanced reservoir heater (what they call Fusion technology).

In both cases, water from a small reservoir is kept warm. This water lasts about 40 seconds to a minute, depending on the water pressure used. When the warm water runs out, instant heating or fusion technology kicks in to keep the outgoing water from getting cold.

Since the A8 has a better heater, the water remains at a higher temperature after the initial ~40 seconds of cleansing.

The U770 Has a High-Pressure Turbo Button

Both bidets have adjustable water pressure and produce an above-average water flow rate. The U770 has a turbo mode that sets the water to the highest pressure. 

All this really does is save you from having to press the up arrows. The A8 user presets let you save your preferred water pressure so this is hardly worth mentioning.

Again, both have decent water pressure, which is nice. Having extra-strong water pressure is important for some bidet users because stronger streams are more effective at cleaning. Also, larger users find that higher pressure is needed for a quality rinsing session. 

Another reason folks like higher pressure is that it’s known to help with bowel movements by stimulating bowel activity (source). Stronger streams can also be used for a makeshift enema since the water better enters the rectum (with the right technique). 

The Ultimate 770 Has Better User Presets 

Having user presets is like having a waiter that always remembers your order. After a few times using the bidet, you’ll probably settle into a handful of settings that you prefer to use long-term.  

Both bidets offer presets, but with the A8, you can only save your preferred nozzle position and water pressure.  

With the U770, you can save nozzle position and water pressure, as well as your preferred temperature settings for water, heated seat, and warm air dryer.  

The A8 Has an Air Deodorizer 

Another luxury feature offered by the A8 is the automatic air deodorizer that eliminates up to 99% of embarrassing odors without the use of fragrances. A small fan at the back of the seat circulates stinky air through a carbon filter that breaks down smelly molecules. 

The A8 Has Microbubble Technology for Greater Comfort and Water Efficiency

Like the USPA 6800U, the A8 Serenity incorporates air into the jet stream in the form of microbubbles. This softens the spray making it more comfortable even at higher pressure settings. 

In addition to making for a more comfortable cleanse, the aerated wash cuts down on water use because air displaces some of the water. So, the A8 is more water-efficient.

The A8 Has a Better Warranty 

The A8 comes with a 3-year warranty while the Ultimate 770 warranty only lasts a year.  

Bio Bidets aren’t prone to breaking, but longer warranties are nice to have, in general. For example, a guest might sit on the bidet lid and crack it, or someone might use the bidet incorrectly. 

The A8 Has a Fancier Wireless Remote 

One cool feature of the A8 is the double-sided handheld remote. It also has an LCD screen, unlike the U770 remote.

The double-sided design makes room for more controls and the LCD screen allows the user to do more with fewer buttons. Hence, you get way more control—you can even adjust the volume of the chimes. 

The A8 Has an Auto Function 

Another convenience feature added to the A8 is the auto function. Having this feature is like being able to order a #1 off the menu instead of specifying everything you want individually.  

It’s nice to have because the user can hit one or two buttons and that’s it.  

By pressing “Auto” during a normal cleanse, the bidet gives you a preset wash: 20 seconds of regular cleansing, 20 seconds of oscillation, 20 seconds of massage, topped off with a 3-min drying session. 

Similarities and Differences of the Spray Nozzle 

Both the A8 and U770 have a single multi-holed nozzle for rear and feminine hygiene, instead of dual nozzles like the USPA 6800U. 

The A8 has a 2-in-1 nozzle (one nozzle with 2 holes) while the U770 nozzle has a 3-in-1 configuration. The extra nozzle hole in the U770 wand is for the turbo function. 

The cleaning wands with both bidets are made of high-quality stainless steel, which is a step up from the plastic nozzles that come with the USPA 6800U. 

Finally, both bidets have on-demand self-cleaning nozzles. Meaning, you’ll have to remember to operate the nozzle-clean function—it doesn’t automatically activate before and after each use. 

The Bio Bidet A8 Serenity vs Ultimate 770: Features and Specs 

The BB Ultimate 770 

BioBidet U770 Ultimate 770 Bidet Seat, Elongated, White

If cost is important, I’d suggest the Bio Bidet Ultimate 770 (Amazon link). You’re not sacrificing much in choosing the U770, and It’s a good deal less expensive (about 15% in my experience). Plus, it has a feature or two that’s missing in the A8. 

It’s worth repeating that neither bidet is available for round toilets. If your toilet has a round bowl, consider the USPA 6800U (article link).

You’ll still get all the important features: extended warm water, warm air dryer, heated seat, sleek wireless remote, modern minimalistic look, adjustable stainless-steel cleaning wand, user presets, child wash mode, oscillating nozzle and massage modes, self-cleaning nozzle, and built-in nightlight. 

To boot, you’ll get a high-pressure mode and nozzle-pulse function, both of which are missing with the A8 Serenity, plus better user presets. 

Features and Specs 

Water Temperature: 

  • Longer warm water flow w/enhanced reservoir + Fusion heating technology.  
  • Adjustable water temp: from 94° F to 103° F.  

Water Pressure: 

  • Adjustable water pressure (5 settings): from 0.13 to 0.21 gallons (or ~ 0.5 -0.8 L) per minute. 
  • High-pressure turbo mode for effective washing.

Comfort, Convenience, and Aesthetics: 

  • Adjustable warm air dryer. 
  • Adjustable heated seat. 
  • Sleek wireless remote. 
  • User presets to save water pressure, nozzle position, and water/seat/dryer temp.  
  • The bidet has a low-profile look overall, despite having a rear height of 7”. 

Seat and Lid: 

  • Soft/gentle-closing seat and lid that saves wear and tear. 
  • Quick-release button for easy bidet and toilet cleaning.  

Cleaning Wand and Spray Capability: 

  • Single, stainless-steel 3-in-1 nozzle for front and rear cleansing. 
  • Adjustable nozzle (5 positions) for accurate aiming. 
  • Oscillating spray mode to hit a wider area and clean more effectively. 
  • Pulsating massage mode that rotates strong and soft water pressure.  
  • Turbo mode doubles as enema function to relieve constipation.

Safety and Sanitation: 

  • On-demand self-cleaning nozzle.
  • Built-in safety sensor to prevent accidental bidet operation. 
  • A child mode that allows kids to operate the bidet with one button while automatically switching all of the settings to be child-friendly. 
  • Built-in soothing toilet-illuminating light for safe navigation at night.  

Water and Energy Efficiency: 

  • Energy-saver mode that, when activated, automatically turns the water and seat temp down during periods of infrequent bidet use.  
  • No aerated wash or high-efficiency water heater. 

The Bio Bidet A8 Serenity 

Bio Bidet A8 Luxury Class Bidet Toilet, Dual Sided Wireless Remote, Adjustable Heated Seat, Warm Water, Air Dryer, Stainless Steel Nozzle, Elongated

Next, is the Bio Bidet A8 Serenity (link to Bidet King). The A8 is nigh impossible to find on Amazon. The A8 Serenity works well for both elongated and round toilets.

On paper, the main perk of this bidet is supposed to be the superior water heater, that sprays “limitless” warm water. As we’ve covered, the warm water does run lukewarm to room temp after a few minutes. 

The tank holds 740 mL, and with a 7 L/min water flow rate, the heated water from the tank will only last about a minute.

But with the hybrid heating technology, the water stream is kept warm for longer and kept from dropping below room temperature. Overall, you can expect a longer warm water supply than with the U770.

One of the other perks is the double-sided remote. The Ultimate 770 has a sleek, yet standard remote control.  

With the A8 Serenity, the remote has controls on both sides, and the LCD display means more can be done with fewer buttons.  

Then, there’s the auto cleaning function and air deodorizer.   

Of course, you’ll get important features like a heated seat, warm air dryer, adjustable stainless-steel nozzle, kids wash mode, user presets, oscillating nozzle function and massage-clean mode, self-cleaning nozzle, and nightlight. 

Features and Specs 

Water Temperature: 

  • Advanced hybrid heater for extended warm water.  
  • Four temp settings including “Off”, low, medium, and high; the highest setting is 102° F. 

Water Pressure: 

  • Five water pressure settings with the highest providing an output of 0.18 gal (or ~0.7 L) per minute. 
  • There is no strong/turbo wash setting. 

Comfort, Convenience, and Aesthetics: 

  • Dual-sided wireless remote with LCD screen.  
  • Adjustable warm air dryer. 
  • Adjustable heated seat w/4 temperature settings. 
  • Dual user presets for saving preferred water pressure and nozzle position.
  • Auto function for one-push easy bidet operation. Hit the auto mode and get an automatic 1-min spray session (using oscillation and massage modes) followed by a 3-min drying session. 
  • Aerated water infused with microbubbles for comfortable cleansing.  
  • A built-in automatic air deodorizer, a feature typically limited to more expensive bidets. A fan pulls air through a carbon filter that breaks down and eliminates offending odors. 
  • Slightly less bulky than the U770 at 6.8” (~17.3 cm) high in the rear.  
  • Low-profile, minimalistic look overall. Hideaway installation feature to give the bathroom a clean look when the bidet is installed. 

Seat and Lid: 

  • Slow-close seat/lid to reduce wear and tear. 
  • Quick-release button for easy bidet removal (for installation/removal, cleaning, etc.). 

Cleaning Wand and Spray Capability: 

  • Single, 2-in-1 stainless-steel nozzle for rear and frontal cleansing. 
  • Adjustable wand position (5 positions) for precise aiming. 
  • Oscillating spray setting for better coverage and more effective cleaning. 
  • Massage-clean mode that causes the nozzle to oscillate rhythmically for a massage effect. 

Safety and Sanitation: 

  • On-demand self-cleaning nozzle. 
  • Soothing blue nightlight for safe bathroom navigation in the dark. No having to turn on blinding lights! 
  • Intelligent body sensor to help avoid accidental bidet operation. 
  • Like the U770, the A8 has a child wash mode allowing easy operation for less skillful users. One push of a button activates child-friendly settings and provides a 2-min cleansing session followed by 3min of drying.

Water and Energy Efficiency: 

  • Eco mode for energy savings. The feature turns down the seat and water temp during periods of infrequent bidet use. 
  • Microbubbles in the aerated wash help cut down on water use.  
  • Higher-efficiency hybrid heater uses less energy compared to the tank heater of the U770. 

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