Waterdrop A1 reverse osmosis hot and cold water filter review
- Josie Shillabeer
- 4 days ago
- 16 min read
Updated: 3 days ago
In-depth review of the Waterdrop A1 reverse osmosis hot and cold water filter. How does it compare to the AquaTru Carafe?
Did you know that while UK tap water generally meets the recommended safety standards, it can still contain unwanted substances such as chlorine, heavy metals, microplastics, and pesticide residues. These substances can each individually affect your health long-term, and therefore as a nutritional therapist, I recommend that everyone in the UK filters their tap water before drinking it.
There are a few different ways that you can filter your tap water. The top two that I would recommend are distillation and reverse osmosis. In this article, I review one of the leading countertop reverse osmosis hot and cold water filters available on the market.
What is reverse osmosis water filtration?
Reverse osmosis is a water purification process that removes unwanted substances from water by using pressure to force it through a semipermeable membrane. This membrane allows only water molecules to pass through, while blocking larger particles like minerals, bacteria, and other impurities.
Waterdrop A1 reverse osmosis hot and cold water filter review
Over the last few months, I have been using the Waterdrop A1 reverse osmosis (RO) hot and cold water filter. This is the second RO water filter that I have tried, the first being the AquaTru Carafe. While I highly rate the AquaTru Carafe, it did not work for our household as a long-term water filtration option—so I went in search of a device that could.
The key things we were looking for in our next reverse osmosis water filter:
A larger tap water tank so that it wouldn’t need refilling so often.
Continuous fast filtration time after a few months of use (no matter the water hardness).
Cheaper filter prices and cleaning costs.
Chilled water (one household member’s key requirement).
Hot water (the other household member’s key requirement).
After doing some research and weighing up the options, I selected the Waterdrop A1 reverse osmosis hot and cold water filter.
Waterdrop A1 Installation
I was really impressed with the chosen delivery service Yodel. I was given advanced warning and a small delivery time slot. The A1 filter was well packaged, and I liked the well-thought-out ‘tear’ tab within the outer cardboard to make unpacking the device easier.
Inside the box contained the RO device, water tank, pre-carbon and reverse osmosis water filters, drip tray, cleaning brush and instruction manual. The instructions were quick to read and easy to follow to get started.
Size and placement
Having not properly worked out the dimensions of the Waterdrop A1 before purchasing it, I was a bit of a surprise at how much larger it was when compared to the compact AquaTru Carafe.
The Waterdrop A1 measures 46.48cm (18.3”) tall, 43.43cm (17.1”) deep and 19.81cm (7.8”) wide. Unlike the AquaTru you need to leave a gap of 20cm (8") either side of the device to allow for air ventilation.
For reference: AquaTru Carafe measures 33cm (13") tall, 35.5 cm (14") deep and 19cm (7.5") wide.
While I had to move the water filter to the end of the countertop, the amount of space it took up felt little more than the AquaTru Carafe. By placing the water filter on the end of the counter, this meant that I only needed to create a 20cm (8") gap on one side of the unit. This also made refilling the water tank much easier, as it was within easy reach.
Quick start
After removing all the packaging and finding the right location for the Waterdrop A1 reverse osmosis water filter, I went about inserting the filters. The filters were almost twice the size of those in the AquaTru Carafe.
The filters felt very premium with their rubberised tops and chunky turn handles. You insert the two filters into the top of the device, matching up the dot at the top of the filter to the closed lock with a dot on the device. It took me a few goes to work out how hard to press down and turn. I was expecting to feel or hear a click to know they were locked into place, but there wasn’t. This is certainly a little something extra that Waterdrop could consider implementing into future designs, so you know they are in the right place.
Waterdrop A1 seven-stage filtration process
The Waterdrop A1 has a seven-stage filtration process:
Non-woven fabric
Activated charcoal layer
Scale inhibitor
Reverse osmosis membrane
PP cotton
Pre-carbon block
Dual UV
CF Filter - Pre-sediment and carbon filter block
The CF filter contains three of the seven filtration stages—PP cotton, carbon block and scale inhibitor. The carbon block is made 100% from the shell of a coconut. The filter is designed to remove sediments, rust, colloids, large particle contaminants, colour, odour and chlorine.
Waterdrop estimates that the CF filter will last around 6 months (£34.99 replacement), but can vary based on usage and local water hardness. I have used the Waterdrop A1 for just over two months at the time of this review, and the handy remaining usage data, which you can access from the A1 touch screen, shows that the CF filter has 62% life left. In running the sums, I can predict that the filter will need replacing after six months of use. I will update this post once the filter officially needs changing. Having expected the AquaTru Carafe CF filter to last six months and only managing three before it needed replacing, this is a very welcome find.
RO Filter - Reverse osmosis membrane filter
The RO filter holds two of the seven filtration stages, the non-woven fabric and reverse osmosis membrane. The RO membrane will filter out particles as small as 0.0001μm. This means that the filter can remove harmful substances, such as TDS, PFOA, PFOS, chlorine, arsenic, heavy metals (including lead), as well as sediment, odour and minerals.
Waterdrop states that the RO filter should last twelve months (£70 replacement), but like the CF filter, this can vary based on usage and local water hardness. After just over two months of use, the A1 shows that the RO filter has 81% life left. Running the sums, I can predict that the filter will last 9-10 months—2-3 months less than the stated amount. One thing to note, however, is that I live in a very hard water area—329mg/L CACO3. While this is less than the maximum level recommended by Waterdrop, it will put additional strain on the RO filter and is therefore to be expected. If you live in a soft water area, then you can expect your RO filter to last longer. I will update this post once the RO filter needs replacing with our exact replacement timeframe.
While the Waterdrop A1 RO water filter may not last the full 12 months, it is certainly less of a disappointment than when I tested the AquaTru Carafe. AquaTru stated its RO filter would last 24 months, but I found it lasted just six. However, the Carafe RO filter lasted the stated number of litres it was designed to filter, and therefore it was more that the AquaTru Carafe is designed for use by 1-2 people—while the Waterdrop A1 is designed for three. If you live in a hard water area, I recommend you choose the Waterdrop A1 as the warranty allows a much higher level than AquaTru.
One area in which the AquaTru Carafe excels compared to the Waterdrop A1, is that they offer the option of a final stage filter that adds health-supportive minerals (electrolytes) back into your drinking water. However, many people who use a reverse osmosis water filter add these minerals back into their water using a pinch of sea salt or a supplement.
Dual UV
The final stage of filtration within the Waterdrop A1 is dual UV. Ultraviolet light directed at water is mainly used to help inactivate bacteria, viruses, and protozoa.
Certifications
The Waterdrop A1 is NSF/ANSI 372 certified. Waterdrop is very transparent about its third-party test data, sharing it on its website for buyers to review. Here is the link to the document. The Waterdrop A1 has also been awarded 'Good Housekeeping Approved', 2025.
Large tap water tank
Once the filters were inserted, I removed the water tank and filled it tap water until it reached the maximum line. I was very pleased that the Waterdrop A1 had the max fill line, a major feature missing from the AquaTru Carafe, because it enables you to know exactly where you can safely fill to.
The removable water tank feels very premium, with a sturdy handle, max water line and large tank size. Unlike the AquaTru Carafe, it slides back into place easily, held not only at the bottom but also at the back. This made the tank fit firmly back into place, and it cannot wobble around, a problem we faced with the AquaTru Carafe.
The Waterdrop A1 removable tank has two sections. The larger section holds just over 4L of tap water, and the smaller section, at 1.5L, holds the wastewater. The A1 tap water tank holds twice the amount of water as the AquaTru Carafe, and while we are regularly refilling it, it holds twice as much as the Carafe. This makes it feel far less of a chore, and we all seem to enjoy the game of roulette—who will be the one who has to refill it?
The one key thing to note about the Waterdrop A1 when compared to the AquaTru Carafe is that when filled, the water tank is very heavy. It weighs almost 5kg when full, and therefore buyers need to establish if they can lift this weight before making a purchase. If you feel this will be a problem, it is best to look for a smaller water tank or an under-counter option.
Waterdrop suggests that the A1 reverse osmosis water filter is suitable for a household of three adults. I have been using the device in a household with three adults, and we feel that this is the right amount for us. Fewer people would mean fewer refills and potentially a longer filter lifespan, while more people would mean more refills and a reduced filter lifespan.
Flushing the system
The next step when setting up the device was to flush the device. This helps to get the filters started and cleans the system through. I really like that Waterdrop was very honest about the amount of wastewater and the time it would take to complete each step, such as flushing. I was not prepared for this when I first used the AquaTru Carafe. Knowing in advance helps buyers for whom wastewater is a problem to choose an alternative device and enables users to complete the flushing process when they have more time.
With the filters inserted and the tap water tank full, I was ready to begin the flushing process. I plugged in the UK three-pin plug and the screen flashed up with a jolly ‘Hello’. I could immediately hear movement within the machine as it filtered water from the tap water tank into the inner tanks (I will tell you more about these later in the article).
I set the language on the screen to English, placed a large mixing bowl to catch the water and selected the flushing option. The device made lots of difference noises as it filtered water into the inner chambers and then out into the bowl. Once the tap water tank was empty, the screen showed it was low on water. Leaving the bowl in place, I removed the tank, emptied the wastewater, refilled it with tap water and reinserted the tank. After a few seconds delay, the Waterdrop A1 automatically restarted its program.
Quick note: This few-second delay after you have inserted the tap water tank is so much better than the AquaTru Carafe. We used to have to turn the Carafe off at the wall each time we reinserted the tank, as it tried to filter the water before you got the tank into place.
I poured out the water from the bowl and wastewater tank three times (12L), and it took 38 minutes (only 8 minutes more than stated in the manual). My arms were feeling quite tired after filling and removing the tap water tank multiple times. Once the flushing cycle was finished, the device was ready to use (except for the cold water option that required adequate time to cool the tank before it was ready).
Two-month review of the Waterdrop A1 reverse osmosis hot and cold water filter
While I have covered several important points within my review of the Waterdrop A1 setup process, there is still so much to tell you. In this next section I am going to tell you some more about the device itself and what my thoughts are regarding using this device long-term (please note that this post will be updated once we have been using the device for six months & twelve months).
Upfront and running costs
Waterdrop A1 has an upfront RRP of £599; when you use our link below, you can get £100 off, making it £499. While the A1 costs £150 more than the AquaTru Carafe, the annual running costs of the Waterdrop A1 are significantly cheaper.
When I ran the sums for some of the leading countertop water filters, the A1 came out with the cheapest annual running costs (filters and electricity):
Waterdrop A1: £177 - £214
AquaTru: £250 - £530
Therefore, while you may need to invest more initially in a Waterdrop A1, the ongoing savings more than make up for this.
Water temperature options - cold and hot water
The Waterdrop A1 is ideal for anyone who regularly requires chilled, room temperature and hot water. There are 6 temperature options: 6°C, 22°C, 45°C, 60°C, 85°C and 95°C.
A member of my household prefers to drink cold water, so when they found out I was testing the Waterdrop A1, with an inbuilt cold water function, they were ecstatic. The A1 has two internal tanks, one of which is specifically for cold water. Water from the tap water tank is filtered into the internal ~1L chiller tank. While the A1 makes noise on and off throughout the day to keep this tank of water cool, it has received a big thumbs up from my cold water loving housemate and guests.
My other housemate likes cups of tea throughout the day and really enjoys using the Waterdrop A1 for its instant hot water capabilities. The hot water dispensing really is instant. I initially thought that while you could easily use the A1 to make a single cup of tea, it wouldn’t be practical for when you have lots of guests. However, I have been really impressed. In the time that it would take to fill and wait for the kettle to boil, I have already served three or four cups of tea to my guests. Because the A1 will remain on the same settings as the last use, it means that you can keep going back for more without having to select the volume and temperature continuously. A downside of the A1 only dispensing water to a maximum of 95°C is that your drink needs to be drunk faster than boiling water from a kettle. All water that is not chilled is stored in the other internal tank.
The A1 has a child lock automatically switched on for hot water dispensing. This is useful not only for protecting children from burning themselves but also adults. I have accidentally hit the dispensing button without checking that it was on the correct temperature, and if it hadn’t had the child lock on I could have burned myself or cracked my glass.
I had hoped that I might be able to pass on my kettle and just use the A1; however; I have found a few situations that have been easier with a kettle. The first is when I want to fill a hot water bottle; it would be a very expensive use of filtered water. Second, when you want a large quantity of warm water for cooking, e.g. pasta or boiled eggs, the water takes a long time to dispense and cools down too much before it reaches the hob. However, an alternative could be to use a saucepan over the stove for these instances, should I wish to forgo my kettle in the future.
Water volume options
You can choose from five different water volumes: 150ml, 250ml, 350ml, 500ml and max. Over time, I have gotten used to how much water to select for each mug, glass and bottle. It is great to set the right amount of water and the temperature and get on with another task while it fills your cup. Plus, you don’t need to panic if you choose the wrong volume as you can press the touch screen to stop dispensing at any time.
Removable tray
The Waterdrop A1 comes with a removable drip tray. Waterdrop has cleverly added a magnet to the back of the tray so that it can easily be detached and reattached to the machine. This is useful as it means I can remove the tray, enabling me to fit in a tall water bottle. The tray stays in place well when in use, and it has saved me a few times when I have overestimated the amount of water I think I can fit into my glass.
Touch screen panel
The Waterdrop A1 is very simple to use, with a touchscreen that controls everything. This is an example of the screen with American measurements, but for UK residents, this will be in Celsius and millilitres. There are two arrows that enable you to view your filter lifespan, flush the system, reset the filters, adjust night mode and off-home mode, settings, and access the manual via a QR code.
Below these are five buttons: child lock, water volume, dispensing/go/stop, temperature and cool water. I still really enjoy pressing the buttons and filling my glass or mug with the water temperature and volume I would like. It is like the feeling of using a fancy coffee machine but for water.
Cleaning and maintenance
I have been pleasantly surprised with the low level of cleaning and maintenance that the Waterdrop A1 requires—especially being in a hard water area. As my previous AquaTru used to return the wastewater into the same tank as the tap water, it used to get scaled up quickly and require descaling. The Waterdrop A1, however, has two separate sections in its removable tank. I have found that after two months the wastewater section has a small amount of scale at the bottom, but the tap water side does not. You need to clean both sides of the tank with soapy water once a week, but it does not need descaling regularly. As the scale in the wastewater tank is not at risk of entering the filters, I know that I just need to descale it occasionally when I feel it needs doing. For this, I intend to use 100% natural citric acid to descale just the tank. Waterdrop states you do not need to run a descaler through the device. This is one area that I will report back on over time, to see if it can survive not being descaled.
Waterdrop A1 cons list
While I have talked highly of the Waterdrop A1 and our household plans to use it for years to come, there are a few issues I would like to share.
Plastic tanks
One aspect I noticed about the Waterdrop A1 RO water filter is that it stores filtered water in plastic tanks, unlike the AquaTru Carafe, which uses a glass container. While I’d love to see a glass or stainless steel option in future models, the current design feels solid and well-constructed overall.
During the first couple of days of use, I detected a slight plastic taste and smell in the water. However, after flushing the system each morning and refilling it, this completely disappeared within about three days. Since then, the water has been consistently fresh and clean-tasting.
Splash back
As noted in other reviews, the Waterdrop A1 has an issue with splashback. When water is dispensed from the A1 into a glass or mug, a little splashes out again, landing on the Waterdrop A1 and surrounding surface. One way around this is to either hold your mug or glass closer to the point of dispensing or add your tea bag, coffee, milk, etc into the mug after you have filled it with water. While this is frustrating and requires regular wiping down, it is certainly outweighed by the Waterdrop A1’s low internal cleaning and descaling requirements.
Water tank hard to remove and heavy
While the A1 water/wastewater tank is easy to insert, removing it again can be a little tricky. I sometimes find that it needs a good yank, and this can cause the wastewater to splash the nearby surfaces. And, as stated before, the larger tank size means that it can be quite heavy, making refilling and re-inserting the tank a bit of a workout.
Noise
There are pros and cons with the variable noises that the Waterdrop A1 makes. My household and I have previously tested the AquaTru Carafe before the A1, and we became frustrated with the noise as it loudly filtered a carafe of water, taking 20-30 minutes. When the A1 is filtering water into the internal tanks and dispensing it into your vessel of choice, it is much quieter and does not last as long. The only time that the Waterdrop A1 can be noisy is when it is cooling the internal chilled water tank. Sometimes it seems to last longer than others. At maximum, I would guess around five minutes, but it is generally just a couple of minutes every few hours. This is a big reason I wouldn’t recommend it to anyone who does not intend to use the chilled water function daily, as it can only be switched off in night and holiday mode. However, if you enjoy chilled water, it is a minor inconvenience.
Standby mode
When I used the AquaTru Carafe, I realised I could save electricity by turning it off at the wall to avoid energy usage in standby mode. With the Waterdrop A1, you cannot do this as it requires continuous power to keep the cool water tank chilled. While it has a night mode that enables you to save on energy usage overnight, I would not recommend this device to anyone who does not intend to use the cold water function daily. If you don’t use the cold water daily, then the water will sit in the tank unused, and the device will be continuously keeping the water cool, using up unnecessary electricity. Hopefully, in the future, Waterdrop will create a range of reverse osmosis water filters that have room temperature water with and without hot and cold water options. For those who are going to make use of cold, room temperature and hot water daily, this is a brilliant machine.
Final thoughts: Waterdrop A1 in-depth review
The Waterdrop A1 reverse osmosis water filter is an excellent choice for anyone who wants clean, great-tasting water at cold, room, and hot temperatures. While its upfront cost is higher than some other RO filters on the market, the long-term savings on replacement filters and descaling more than make up for it.
The A1 is ideal for households of up to three adults and performs especially well in hard water areas. Although there are a few minor drawbacks — such as splashback, internal plastic tanks, some noise, and the inability to turn off only the internal chiller tank — these are easily outweighed by its many advantages. Its large water capacity, sleek modern design, durable filters, and instant hot and cold water dispensing make it a standout choice.
Overall, I highly recommend the Waterdrop A1 for anyone who regularly uses both cold and hot water and wants a stylish, reliable countertop reverse osmosis system.
How to use our Waterdrop discount code to save £100
You can get £100 off your Waterdrop A1 water filter when you click on the button below and enter code WDA1 at checkout.
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For reference: Waterdrop A1 reverse osmosis water filter was installed 20th August 2025.
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