KJ600 Instant Hot Reverse Osmosis System, 600 GPD, Tankless RO

I've owned the Waterdrop K6/KJ600 under sink reverse osmosis system with instant hot water for about two years, and it has been one of the best upgrades I've made to my kitchen. The water tastes exceptionally clean, having instant hot water for tea, coffee, oatmeal, and cooking is incredibly convenient. The system has been reliable, and the filter replacement process is quick and straightforward. After nearly two years of ownership, I experienced an issue and contacted Waterdrop Customer Service. That's where Becky C made all the difference. Becky was responsive, professional, and genuinely committed to helping me. She communicated clearly throughout the entire process, kept me updated, and worked quickly to resolve my issue. It's rare to find customer service that is this attentive and easy to work with, and I truly appreciated her dedication. Any product can experience an issue over time. What really matters is how a company stands behind its products, and my experience with Waterdrop gave me confidence that they do. Thank you, Becky, for providing outstanding customer service and making what could have been a frustrating situation into a positive experience. Between the quality of the K6 system and the excellent support I received, I would confidently recommend Waterdrop to anyone looking for a premium under sink reverse osmosis system with instant hot water.

Ease of installation, everything is labeled, colored and easy to do. The only down side was that it is large, and in order for me to fit it under the sink, I had to remove the garbage disposal first. Not difficult, just one additional step. One item that is a little confusing is the initial turn on step and like most filters, you have to let it run for a certain amount of time, or certain amount of water. The directions made it seem that it would do this on its own, once the startup was initiated. In order to fill the filter though, you still have to turn on the cold water and let it run for a while in order to flush and fill the filter. Then it will allow you to set the hot water temperature. It works great, water is hot as you need it, and it tastes great, or should I say, it doesn’t taste like anything.

I've been seeing articles about microplastics in our drinking water supply for several years, and then I saw a paper about them being able to cross the blood brain barrier. No idea if that passed peer review, but if it was correct it seemed unlikely that micro-plastics in the brain would give me super powers, and a more likely speculation that longitudinal studies will show something like a dementia risk. So... RO filter. I've no affiliation with the company beyond appreciating their product enough to write a very rare Amazon review. There is very limited counter space available, so I was looking for an under-counter unit. The kettle was also starting to fail so I went looking to see if there was a filter that integrated a hot water option to reclaim additional counter space. This was the only unit on the market at the time. Did a bunch of additional background reading around standards specifications and came away content that it'd be fit for purpose. Although if you want to hook it up in-front of a fridge icemaker or similar this isn't the unit for you. This unit isn't cheap and I did look at a water fountain with subscription as an alternative. The subscription looked very slightly more expensive yearly than filter replacement, but without the substantial up front cost. However storage space is a premium for me and I cannot afford the space for the cache of water a fountain requires, nor the footprint of the fountain. I called around looking for plumber quotes for just the install if I supplied the unit, and they came back in the $1k+ range. Okay, how hard can this be for self-install? (FYI I did look at drilling a new hole into the stainless steel sink, but luckily could avoid it through purchase of a different faucet. If you go down the drilling path, look at tips to avoid "work hardening". Plumbers can be worth the cost because they know this stuff without expensive and difficult to correct "learning experiences".) Ordered it, it arrived, seems I needed to order more stuff. This was entirely on me, but as a service to amateur self-installers there could be a "things to look for " section in the product doc. I'll put links to the additional purchases. To avoid having to cut and weld copper, I replaced the existing faucet with one that had flexible braided hose instead of rigid metal. To avoid back siphoning and comply with local code I switched the existing air gap for the dishwasher with a dual intake one. This sits between the dishwasher/ROfilter and the waste line. Because I was moving from a faucet with a wide base to a small base, exposing one of the sink's pre-cut holes, I filled that with an under sink dish soap dispenser. Final enhancement was a remineralization filter on the cold output as, if this is a primary source of hydration, you don't want your drinking water causing necessary dissolved minerals to osmose out of your cells. The unit was easy to install... although I had to return the first one due to it failing to complete initial self-checks. The swap was incredibly smooth - their support had a replacement unit on the way the same evening after I described symptoms, the checks I'd done for free-flow of water, and sent photo/video. IIRC the replacement unit arrived a day later, I slapped a return label on the original and was done. I'm noting this because good support of products is a massive positive differentiator for me when they're sealed systems. Install: The install was simple. The hoses are all push fit and, so long as you apply the little retainer clips, no leaking at all after installation. I did diverge from their install instructions regarding the waste water line - that was a push fit into the air gap instead of drilling a small hole into the sink waste line. Use: The water comes out _almost_ boiling. You do have to run it for a second or two to flush the cool water in the pipes if you want it for tea, but if you do it is definitely sufficiently hot for tea and coffee. The temperature read-out on the faucet tells you when you're good to go. In terms of volume, I've not run out when pulling 3-4 cups at a time for cooking rice/pasta/etc. In fact I've not run out of hot water when I've needed it, but your usage patterns will dictate whether this is a viable total kettle replacement for you. When first using it I did wish for more tactile feedback on the top of the filter faucet - I'm watching a stream of boiling water near my fingers like a hawk, so looking away to find the "off" button on a completely smooth touch surface was... uncomfortable. After a short adjustment I'm now able to turn it off without looking away from the water so it's not a lasting issue, just a learning curve. There is noise when it's in operation, but it's pretty muted just by thin, un-insulated wood panel cupboard doors. My sleeping area is a loft above the kitchen space, and I'm a light sleeper, but this is not enough to disturb me. I was adjusting the temperature of the hot water down before bed, then up again before morning routine to reduce energy expenditure, but have given up on that. This shares a power meter with the dishwasher so I don't have isolated reading. Looking at it, it's currently drawing 2.2w. It's 06:18, I've had 1 coffee, and it's drawn 0.14kWh total since midnight. I've never bothered to adjust the temperature from maximum after initial experimentation. This isn't a kettle, and if you adjust the setting it does take time for the temperature to ramp up, which is not suited to my primary use of hot drinks. I want waster very hot and without delay. I've no idea how long it takes the temp to drop, but given power draw I have to assume decent insulation and therefore quite some time. I do wish I could set the temperature display to Celsius, but it's sold in the US so that's a very minor critique. I would have liked some average power consumption figures in their product docs for X liters of cold, Y of hot per day but after observation power consumption is low enough for me to ignore. The only reason I've put this as room for improvement is that for the very energy conscious this would benefit from a small zigbee controller between faucet and filter that allowed adjustment of temperature on a schedule. I agree with their design choice _not_ to clutter the filter faucet with controls for such a setting. I've not had this for long enough yet to be able to comment on filter life/replacement. Not affiliated with any of these sellers either. airgap: https://www.amazon.com/gp/product/B092RFBTXK/ref=ppx_yo_dt_b_asin_title_o00_s00?ie=UTF8&th=1 faucet: https://www.amazon.com/gp/product/B092VQTNW1/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&th=1 soap: https://www.amazon.com/gp/product/B018WUPCRA/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&th=1 additional push-fit host: https://www.amazon.com/gp/product/B08619RF3G/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1 remineralization: https://www.amazon.com/gp/product/B08DXYL81C/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1

The K6 is very effective; it reduces our TDS by 90%. It does not take up much space and is also easy to install. The following are just from my experience as a lay person and should in no way be taken as recommendations to anyone to do the same: 1. Like many other homes, ours has only two outlets under the kitchen counter, one for the dish washer, the other the disposal, each is required to be on its own power source. Our solution is to use a two-outlet air switch, which, by only sending juice to one of its two outlets at any given moment, satisfies the building code. 2. We decided to put the dish washer and the disposal on the two outlets of the air switch. This is because, if the K6 and the disposal are put on the air switch outlets, every time we use the disposal, the power to the k6 is cut off by design. When the disposal is disconnected and power to the K6 is in turn restored, the K6 interprets it as a hard resetting and does a very energetic flush. We figured too many hard settings might not be good for the health of the K6. Besides, the strong flush would send water splashing up the drain into the sink (unlike the K6's regular flush after uses, which is very gentle). 3. Regarding how to get cold water/turn off cold water, the Instruction Manual says on Page 9: "Touch the cold water key to get or turn off cold water." I thought this meant it takes only one touch of the cold water key to get cold water. It turned out, however, (unless one has used the system seconds ago) it takes two touches. At first, I thought there was something wrong with my K6. But further research by watching other K6 owners' videos has led to the conclusion that two-touch is actually normal: the first touch (of any key) wakes up the system and the second touch (of the cold water key) gets one the water. My confusion was caused by the Instruction Manual which does not mention the need to wake up the system anywhere. All in all, the K6 is a very nice RO filtration system. I only wish the Instruction Manual may be improved. I highly recommend this system.

I purchased this product over two years ago to filter tap water to purify drinking water and reduce water hardness. My tap water has over 200ppm, and I was shocked to find that the GE refrigerator water filter was only able to reduce that to 160ppm. I had hard mineral buildup on my automatic coffee maker, humidifier, hot water dispenser, etc. After searching for a RO water filter system, I came across this Waterdrop RO system with high end filtration that met the NSF/ANSI 372 certification, is compact, provides great water flow, provides heated water on demand (for tea/cooking/etc), and has extremely easy to change water filter. After installation and startup, the water hardness was reduced to 5ppm! I have been using for over two years now and hard mineral issues are no longer a problem for my various appliances. For a family of four, after one year of extensive water use (drinking, appliances washing fruits/vegetables, etc), this RO system still filtered water to a hardness of 30ppm. I didn't expect it to work so well. There was a con - after a week away, I found the water heater no longer worked, and I could not restart it following the manual instructions. However, I contacted customer service who surprisingly picked up the telephone call after hours on a weekend. They walked me through to resetting the system and ensured it was operational again. They followed up with me on a daily basis for a few days via email to ensure the system continued to work. Another con (small con) is the touch sensor on the dispenser - if your fingers are wet, sometimes the touch does not register. An improvement would be to have mechanical buttons. In sum, I am very happy with the quality, functionality, longevity, and customer service for this system. If you can install this or find someone to install, I highly recommend this RO system.

Never tested quality of water, just trusted TDS display. Tasted and smelled ok. Instant hot is the problem. Was always on at random times with loud churning noises. At one year the lock button no longer functioned. Then another 10 months (now) it made super noisy nonstop 80 db freight train sound until I unplugged it to make it stop because all other buttons didn’t function. I cycled it on again but kept getting E05 error and no hot water. Worse of all as E05 error tells you to contact Waterdrop right away ( 24/7 service my A…) there is no answer. Called next day got some dumbo who made me do the whole cycle all over again though I said I already had multiple times. Guy kept talking over me like a robot to get thtough his script and ignored me. Said if it didn’t work after 15 minutes to call back to ‘escalate’ it. Of course after 15 minutes it didn’t work. Left hanging on phone cue after 2 hrs (‘you are 1st in line’). No answer. Friend tried calling while I was 1st for over 1 hr got fast busy signal repeatedly. So much for customer service. To sum it up DO NOT BUY!! Get whole house RO and standard instant hot tap instead. This product is nothing more than a cheap ‘Made in China’ piece of trash. So is the ‘ customer service’.

I waited to do this review for 6 months because this appliance seemed too good to be true. Oh my! This RO WATERDROP WD-KJ600 is Absolutely Perfect! Remodeled my kitchen and had this installed in place of my 3 filter big black tank RO unit in Dec 2025. Oh my, so many things about this unit I love. #1 Instant filtered tap temp or hot water up to 203 degrees (with safety lock). Never drips. When you tap off, it's off. #2 Beautifully designed. Very simple to use. Swivel nozzle allows for filling big pots or small tea cups. #3 I've water tested and taste tested against my favorite RO bottles Dasani, Aquafina, PurLife. Taste exactly the same and water test at/or just 1-2ppm better. So I can finally cut way back on plastic bottle usage. #4 A total space saver in your cabinet and it looks beautiful. Additionally, the single filter with access truly at you fingertips is HUGE. You will NOT regret this purchase. I love my WATERDROP!

I am on well water, and I have a very expensive whole house filter, scale remover, and silver bio filter. The well water at the sink still tastes bad, so I added a large flow water filter under the sink. This feeds both an instant hot water system and the sink faucet. Even with this double filter system, both the hot water and sink water tasted bad. The refrigerator ice maker on the other side of the kitchen was also having issues with its built-in filter because as the ice sublimated, it would leave a white powder residue behind, and the ice/water tasted bad as well. As the ice melted in your drink, one could see little white particulates at the bottom of the glass. So, all drinking water was bad, and I resorted to using 5-gallon filtered water on a cooler. There had to be a better solution. I am a hot tea drinker, and I wanted clean good tasting water from my well and stop having to buy the expensive 5-gallon water jugs at the store. So, I bought the Waterdrop 600GPD hot/cold water RO filter dispenser to go under the sink. I installed the Waterdrop and left the large flow filter that I installed earlier to filter the large sink faucet water. I was a little worried about the water pressure now having three filters in series and had a concern whether the 600GPD Waterdrop filter had a sufficient flow rate. My well runs at 75psi, but it has a large 3hp 3-phase AC pump that has at least a 29 GPM flow rate. I followed the Waterdrop filter install instructions and let it do its 15-minute flush. Then I tasted both the room temp and the hot water from the Waterdrop RO system. The glass surprisingly filled quickly. It only took a few seconds to fill the glass. Even with two filters in front of this third RO filter. What a success! Finally, I have pure water with no after taste and no particulates! When I opened the under-sink fill valve for the first time and sent water to this filter, the hot water took a few moments to preheat, but after this pre-heat, the hot water was instant. I have my temp set to 203 degrees F. I also disable the hot water child safety feature on the faucet head by touching the safety control and holding for about 6 seconds. You will hear a beep at about 2 seconds telling you that you can now touch the hot dispenser control and if you keep holding for about 3-4 seconds longer, the safety control will turn off and you can now get instant hot water by just touching only the hot dispenser control. I did have an issue with the Waterdrop faucet display being very hard to see. The display on the main under sink unit was fine, but the faucet display had an issue. Instead of sending the unit back through Amazon, I elected to contact the manufacturer directly by email. Their customer service responded the very next day. They asked for a few photos, and I asked them via email, could I just get a new faucet head only since I did not want to uninstall the whole system and ship back with water in it. One day later they responded that they would ship at their cost a new faucet head with a good display. Each day they checked in on me via email to see if I was having any issues installing the new faucet. They were very nice the whole time. I got the new faucet unit and all is awesome now. Their customer service by email was fantastic. They checked in on me almost every day and were patient with me and gave me time to install the new unit without closing the service ticket. They never abandoned me. They even checked in on me for over two weeks after I had told them I was successful with the replacement faucet install just to make sure I had time to use the unit and see if any issues surfaced. The unit is working very well. The email service people are just fantastic! So, all is well and both hot and cold water is fantastic. Crystal clear and no foul after-taste. I most certainly could remove the second under sink filter I have in front of this unit, and I may do that, but my water flow is fast, and everything is awesome and working well. Great clear water. Finally!!! Another few topics for DIY people... If you do not use the dispenser for 48 hours, the Waterdrop hot water filter will go into standby mode to save power. I use it every day, so I have no problem with a delay. There have been a few times I did not use the unit for a few days, and I had to wait for it to come up to temp, but it was a short couple of minutes. No big deal at all. The faucet display will inform you if it is pre-heating, so you don't panic about what is going wrong. The faucet display shows everything you need...temp, TDS, what is running (cold or hot) and it also has the up/down temp settings where you can easily adjust the temp. You do NOT have to keep touching the contact for hot or cold-water flow. Just touch until you hear a beep and let go. The water will keep running and when you want it to stop, simply touch the contact again. This is a great feature if you are filling large containers with either hot or cold water. Just sit the container in the sink and fill completely hands off. The following is a tip on how to better install the faucet water lines to the under-sink base unit. I have a very deep sink and only have a few inches clearance between the top of this unit and the sink bottom. This unit has a supply, hot and cold faucet lines, and a wastewater line attaching to the “top” of the under-sink system instead of the back or sides. That really is a tight fit and requires the water lines to bend 90 degrees within a few inches. The following is a must do to prevent damage or leaks…I bought what they call “90-degree bend guides” for ¼-inch and 3/8-inch push-in tubing to prevent the lines from kinking. (Waterdrop, you might want to include three ¼-inch and one 3/8-inch bend guides in your install kit.) I will include the pictures below. One can buy the bend guides on amazon for a few bucks, and you just snap in the tubing at one end and walk up the tubing with your fingers and push the tubing into the bend guide as you go. Now you have a 90-degree bend in your three ¼-tubing (wastewater, hot water, cold water) and you will also need one 90-degree bend guide for the 3/8-inch supply tube. Now your under-sink unit will fit nicely under your sink and never kink the tubing especially if you need to pull the base unit out from under the sink or rearrange its position. Now a quick story about how I used a Waterdrop filter on my refrigerator… I loved the hot/cold Waterdrop unit on my kitchen island sink so well, I have bought another Waterdrop basic 600GPD (without electronic controls on the faucet…this is extremely important to make this work with your refrigerator ice-maker/water dispenser) and hooked it up directly to my refrigerator which is against a wall with a bathroom sink on the other side to provide service for the waste water. Now I have crystal clear ice and cold drinking water. I had wrongly bought a refrigerator filter bypass/plug since this new Waterdrop RO filter is all I needed but learned that most new refrigerators have a built-in bypass and do not require a plug. You simply unscrew the filter from the refrigerator and just close the housing cover. Now I do not need to keep replacing my refrigerator filter. Those are expensive and are not required when you directly hook these Waterdrop filters in-line with the fridge. The refrigerator filter will also drop your water pressure too low to reasonably fill the ice maker or dispense water. I will say this important fact again…I bought a basic 600GPD Waterdrop filter with a simple “non-electronic” faucet because when you directly hook up the filter to the fridge, the electronic faucet with dispensing controls is not compatible! The simple non electronic Waterdrop faucet design allows the fridge icemaker and water dispenser to automatically work because the base unit will automatically work on just a pressure drop, not an electronic control. For those who want the Waterdrop filter to service the refrigerator and a basic non-electronic faucet to fill up large 5-gal jugs for a water cooler…You could tee off the Waterdrop filter output, one line to the fridge and one line to the basic non-electronic faucet. On my setup, I do not use a faucet but instead use a tube with a valve at the end and make it with the tube sticking through a cap that fits over a 5-gallon jug top. That way I do not have to hold the tube and I can more easily turn the valve off when the jug is full. After installing and flushing your Waterdrop RO filter, I would recommend throwing away all the old refrigerator ice and the first few new ice drops as well. Overall, I would rate the Waterdrop filters a 5-star, and I will gladly give the Waterdrop email customer service a 5-star as well. As of writing this review, the email service department periodically still checks in with me to see if all is well. That deserves an extra star, and I wrote back to the service department thanking them several times.

Such a great solution. It is really as described. Good water flow, instant hot water. Regarding the noise it is not that much and you can hear the sound for seconds. The only disadvantage is if you want to change the temperature for the hot water you need to wait until the system adjust, it will take couple of minutes.

Ho installato il depuratore ma non mi da indicazioni della temperatura, TDS e non parte la scaldiglia, sapreste aiutarmi a capire il problema?

I’m really impressed with the Waterdrop Reverse Osmosis System! I use it to make my baby’s formula, and it has saved so much time. Having instant hot and cold water on hand is super convenient, and I feel safe knowing the water is clean and filtered. It was super easy to install and works great. The instant hot water dispenser is a huge bonus, perfect for coffee or tea. The cold water is always crisp and refreshing, and the smart LED faucet makes it easy to check the water quality. The smart LED faucet is a nice touch too. Definitely recommend it for anyone looking for a reliable water filtration system!

Ho deciso di acquistare il Waterdrop Sistema di Erogazione Istantanea di Acqua Calda a Osmosi Inversa WD-KJ600 (600 GPD, senza serbatoio, rapporto 2:1) dopo una precedente esperienza non particolarmente positiva con un altro prodotto dello stesso brand, il Waterdrop G2P600. Proprio questa esperienza iniziale è stata determinante nella scelta: speravo che un modello più costoso, più evoluto e con funzionalità aggiuntive potesse risolvere le criticità riscontrate in precedenza. Purtroppo, le aspettative non sono state soddisfatte. Parto dal contesto: con il G2P600 mi ero trovato male principalmente per due motivi. Il primo, molto serio, riguarda la reperibilità dei filtri di ricambio. Dopo circa sei mesi dall’acquisto, i filtri non erano più disponibili su Amazon e potevano essere acquistati solo tramite un sito estero non italiano, con costi di spedizione elevati e tempi lunghi. Il secondo problema era la durata reale dei filtri, che sulla carta avrebbero dovuto garantire almeno 12 mesi di utilizzo, ma che nella pratica si sono esauriti in circa 6 mesi. Nonostante tutto, però, quel modello base aveva un punto di forza importante: la qualità dell’acqua filtrata. All’inizio riuscivo ad ottenere un valore di TDS intorno a 21, un risultato eccellente per un sistema domestico a osmosi inversa. Proprio per evitare di ripetere gli stessi errori, ho deciso di investire di più e acquistare il WD-KJ600, convinto che un sistema di fascia superiore, con erogazione istantanea di acqua calda, rubinetto LED intelligente e una portata elevata da 600 GPD, fosse più affidabile anche sul fronte della filtrazione. Dal punto di vista costruttivo ed estetico, nulla da dire: il sistema è moderno, compatto, ben progettato per essere installato sotto il lavello e l’assenza del serbatoio è sicuramente un vantaggio in termini di ingombri e igiene. Anche il rubinetto LED è intuitivo e ben realizzato. Il problema principale, però, resta ancora una volta la qualità effettiva della depurazione. Fin dai primi utilizzi ho notato valori di TDS costantemente superiori ai 300, un dato decisamente deludente per un sistema a osmosi inversa di questo livello e prezzo. Ho effettuato più misurazioni, in diversi momenti, convinto inizialmente potesse trattarsi di un assestamento iniziale dei filtri, ma la situazione non è mai migliorata in modo significativo. Questo è particolarmente frustrante se confrontato con il modello base, che almeno nelle prime fasi garantiva un’acqua con TDS estremamente basso. A rendere il tutto ancora più scoraggiante è il fatto che anche su questo modello si ripresentano le stesse incertezze legate ai filtri: costi elevati, disponibilità non sempre chiara e, soprattutto, una resa che non giustifica né il prezzo dell’impianto né quello dei ricambi. Quando si acquista un sistema di questo tipo, l’obiettivo principale dovrebbe essere la qualità dell’acqua, e purtroppo è proprio su questo aspetto che il WD-KJ600 fallisce. In conclusione, nonostante le ottime specifiche sulla carta, le funzioni avanzate e un design curato, questo sistema non ha mantenuto le promesse. Spendere di più non ha significato ottenere un’acqua migliore, anzi, sotto il profilo della depurazione pura, l’esperienza è stata addirittura peggiore rispetto al modello base. Per chi valuta un impianto Waterdrop, consiglio di riflettere molto bene soprattutto sulla gestione dei filtri nel tempo e sulla qualità reale dell’acqua filtrata, perché almeno nel mio caso il rapporto qualità-prezzo risulta decisamente deludente.

I was looking for a compact, "all-in-one" hot water + RO system and the KJ600 seemed to be the best (and one of the only) choices. The interface is certainly reasonably user friendly--I've only had to give brief instructions to friends and relatives who want to use it. The fact that the hot water boiler is integrated and does not require extra cabinet space is absolutely brilliant. I don't think there are any equivalent choices on the market! I only recently (1.5 years after my purchase) had the chance to install it and for a few months, it worked flawlessly. Hot water at 185F "on demand" with cold water, from the same tap without 2 separate systems taking up room, was perfect for our family's needs. Unfortunately, that wouldn't last because 2 months in, I started getting E05 errors. Why did I give this a 5-star review, even after the unit failed? Because of Waterdrop's customer service and their rep, Becky in particular. After some back and forth troubleshooting, Waterdrop sent out a replacement unit. The reality is, electrical and mechanical items will always have some failures, even when brand new. My question is what the manufacturer (and seller) will do about those odd cases. Waterdrop/Becky certainly stepped up and stood behind their product, even when technically, it was "out-of-warranty." Oh, the replacement unit is running flawlessly. Hopefully it will continue to do so!