Best Reverse Osmosis Systems With Hot and Cold Water (2024)

Last updated Feb 15, 2024

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It’s no secret that everyone loves convenience, and the best reverse osmosis system with hot and cold water is just that. Are you tired of boiling water or getting your baby formula temp just right? If this sounds like you, an RO system with temp control takes out the guesswork.

The purpose of this article is to introduce you to the current top systems in this category. You’ll find solutions for home, office, apartment living, and even for your RV.

In addition to the advantages previously listed, you’ll also eliminate scaling inside your kitchen appliances. Plus, you’ll be able to ditch your old method of heating water. Beyond those points, these new hot/cold RO systems are some of the most advanced available.

So, without further ado, it’s time to explore an overview of the units before taking a closer look at them in our individual reviews.

Model Specifications
#1) Waterdrop K6

Waterdrop K6 hot & cold RO system
  • Capacity (GPD): 600
  • Weight: 31.9 lbs
  • Dimensions: 6.7″ x 17.5″ x 16.6″ (LxWxH)
  • Stages: 5-Stage Single Composite Filter (1-Year Life)
  • Price: $$$$
#2) NU Aqua 4-Stage Countertop Reverse Osmosis System With Hot Water

NU Aqua 4-Stage Countertop Reverse Osmosis System with Hot Water YU-CTRO-W
  • Capacity (GPD): 75 GPD RO Membrane
  • Tank Size: 16-Cup
  • Stages: 4
  • Price: $$$
#3) SimPure Y5 Insta-Hot Countertop Water Purification System

  • Tank Size: 1.3 Gallons
  • Weight: 19.86 lbs
  • Dimensions: 8″ x 16″ x 18″ (LxWxH)
  • Stages: 4
  • Price: $
#4) Brio 400 Series RO Bottleless Water Cooler

  • Capacity (GPD): 400 GPD
  • Weight: 52.9 lbs
  • Dimensions: 12.2″ x 14″ x 41.1″ (LxWxH)
  • Stages: 4
  • Price: $$

Reviews of the Best RO Systems With Hot & Cold Water

As you’ve probably already noticed, each of these systems excels in different situations. For instance, the Waterdrop system is a great all-around choice, while the Brio unit shines best in an office setting. Having said that, all of these systems are great options for residential use.

Below, you’ll get the chance to take a closer look at each system and the pros & cons of ownership.

#1) Waterdrop K6 Reverse Osmosis Instant Hot Water Dispenser System

Waterdrop K6

Waterdrop is one of the most innovative water filtration companies in the reverse osmosis space. Seemingly, they’re always one step ahead of the competition. For this reason, their latest system, the K6, topped our list.

What makes this system special? Firstly, it’s the only system that features an under-sink installation with both hot and cold options. Also, it achieves this while still serving instant hot water on demand.

The versatility of this system lies in the dual-function faucet that allows for both hot and cold H2O from a single spout. Next, it’s important to note the many features offered by this unit. Collectively, there are temperature adjustments, TDS readings, an included smart faucet, easy filter changes, a filter life indicator, and even a child lock.

You’ll love that this system uses a single composite filter with an internal RO membrane. This means that you only need to worry about changing one filter per year rather than tracking multiple.

Lastly, the hot water flows at .4 gal/min, and there’s a 2:1 purified water to wastewater ratio to help you save money on your water bill each month. The only real drawbacks to this system are its high price, short warranty, and the onboard hot water tank is smaller at 70 oz.


  • Save valuable counter space with the under-sink installation
  • Smart faucet with precision temp control
  • Dual-temperature faucet
  • Optional remineralization by connecting a mineral filter to the cold water line
  • Automatic cleaning flushes
  • Single filter tracking


  • High cost
  • Short warranty
  • Smaller hot water reservoir than SimPure and NU Aqua

#2) NU Aqua 4-Stage Countertop Reverse Osmosis System With Hot Water

Another excellent water filtration company is NU Aqua. In fact, they manufacture one of the smallest reverse osmosis systems on the market. Firstly, this is our top pick for the best countertop reverse osmosis system with hot water.

Clearly, you’ll have to designate some counter space for this unit if you choose it over the Waterdrop K6. Having said that, the installation is even easier since you don’t have to make any modifications below your sink. Renters will find extra value here.

Now, one of the greatest selling points of this system is for expecting and new mothers who want a good water filter for baby formula. Because with this system there’s actually a designated button for making baby formula.

Next, you have full control over temperature with the option to turn off the heating element. Plus, there are both TDS in and out readings to know exactly what you’re getting in your cup.

After those considerations are the filters. This system has two filters with a 75 GPD capacity RO membrane. You’ll be happy to know that this system is NSF, FDA, and WQA certified to remove common water contaminants. And this is more than most companies with unknown origins offer.

Finally, NU Aqua offers a 1-year limited warranty with the option to extend for free by registering your product online.


  • Convenient countertop installation
  • Baby formula preset
  • Full temperature control
  • TDS in and out readings
  • Quick filter changes
  • 1-gallon hot water tank


  • Dispenses 16 oz max each time
  • The need to use counter space

#3) SimPure Y5 Insta-Hot Countertop Water Purification System

Now if you’re on a tighter budget, the Y5 by SimPure is currently the most affordable RO system with hot & cold water in our guide. Similarly, it functions much like the NU Aqua system as a countertop unit. One key difference that we do like about this system is the addition of a post carbon block filter. This filter functions as a final stage after the RO membrane to improve the overall taste of the finished product.

Next, the system’s compact footprint ensures that you’ll be able to squeeze it in just about anywhere. Plus, it’s essentially plug-and-play with no need for a complicated installation. As for the controls, they’re not quite on par with what NU Aqua and Waterdrop both offer.

On this unit, you’ll find options for tea, coffee, milk powder, and ambient without the option for precision temperature control. However, this is one of the tradeoffs of paying less for the system.

Additionally, there are no TDS readings, yet this system does alert you when it’s time to change the filters. And changing the filters takes just a few seconds with no tools required.

Overall, the Y5 is a good affordable option that doesn’t offer as many luxury options as the Waterdrop and NU Aqua systems.


  • The most affordable option (at the time of this writing)
  • Compact design and footprint
  • Easy filter changes
  • Baby formula mode
  • Larger hot water tank than NU Aqua


  • No TDS readings
  • No precision temperature control
  • The control panel is limited compared to NU Aqua and Waterdrop

#4) Brio 400 Series RO Bottleless Water Cooler

Last up is a system that’s slightly different than the preceding systems. Rather than living on your countertop or below your sink, the Brio 400 is a standalone unit that can optionally be placed on a counter with enough clearance.

Firstly, this system is unlike the preceding systems in that it serves both piping hot water and cold water. Because of this, this unit serves the coldest RO water of the systems in this guide.

Next, the 400 Series is great for both residential and commercial use. So if your goal was to find a hot & cold RO system for an office setting, this is the one. The triple faucet dispensing system prevents having to wait in line and ensures that both hot and cold water are ready on demand. Plus, there’s the option to dispense ambient temperature drinking water.

Below the dispenser is where you’ll find the water filters, and this unit makes changing filters easy. In total, there are four filters to track. Lastly, the 400 Series features a child lock, removable drip tray, and self-cleaning mode to keep your water fresh at all times. All in all, the Brio 400 is one of the better reverse osmosis bottleless coolers on the market that won’t break the bank.

Brio 400 Series filter changes


  • Triple-faucet design (cold, hot, ambient)
  • Self-cleaning mode with ozone
  • Child safety lock
  • Allows for multiple users at once
  • Stainless steel construction
  • Quick-change filters


  • More wastewater production
  • Larger than the other units
  • No TDS readings or filter life indicators

Bottom Line

In total, there are three options when choosing the best reverse osmosis system with hot and cold water. Those are under-sink, countertop, and standalone models. Depending on your needs, there’s a model listed above that’s perfect for you.

Keep in mind that the Waterdrop system is the first of its kind. Rather than having to eat up counter space, the K6 allows you to dispense both hot and cold RO water from the same faucet. For this reason, convenience does come with a higher price tag.

Next, if you’re okay with using some counter space, the NU Aqua system is the most advanced countertop hot & cold RO system on the market. Alternatively, SimPure’s Y5 is comparable minus the more advanced control panel.

Finally, Brio is one of the leaders in the bottleless water cooler space, and its RO units are some of the best you’ll find. Currently, the 400 series offers you the most value, and it’s a perfect addition to any office or home that’s in need of a reverse osmosis water dispenser.