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

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.

I was and still am a most satisfied customer. The system worked beautifully for a year when it indicated that it needed to change the filter. I changed the filter, and flushing and priming happened automatically all on its own. This was wonderful. Automated after-filter change routine that worked!! The system worked for a few days, then something happened: The system all of a sudden behaved as if it were unplugged; there are no indicator lights on the faucet or the main unit. While it still dispenses water, it only dispenses cold water regardless of whether the cold or hot water button is pressed. During dispensing, the cold water button on the faucet blinks, and the blue KJF filter light on the main unit illuminates momentarily. So naturally, I emailed the customer support. They were very polite, however, likely because they were trained that way. Their instructions and diagnosis of the technical problem were the worst I have ever experienced. After a long email thread, they started repeating the instructions and diagnosis. Other ather words, they did not review previous communication. Utterly frustrating, meaningless, and a waste of time. If the support team had bothered to ask technicians, the support would have been quick and meaningful. I started giving them a summary of past communications to break the endless cycle of the same opinion and diagnosis. Finally, they decided to turn this over to a technician after over a week-long exchange and over 10 emails later. A day later, they emailed me that the technician said the system was going through a "rinsing cycle", based on the video I sent them at the beginning of all this. And instructed me to let the cold water run, and after the cycle is complete, the heater would turn on. They did not say how long it would take to complete the cycle or whether it would stop dispensing water automatically. I had to ask Gemini AI, and it said the cycle would be 5 to 10 minutes and it would stop automatically. So, with the customer's/technician's support and AI help, I was able to complete the "rinsing cycle," and the heater came back online. I did not expect it needed a "rinsing cycle", which is essentially flushing and priming, after successful flushing and resetting. I do love this product and what it does for me. I love the automatic routines after a filter change. This is a well-designed and extremely convenient product for me. But contacting customer support is not something I wish to repeat. I do not know how many stars to give to this product: 5 stars for the system performance and less than 1 star for their customer support. I would ask AI first next time the system fails instead of contacting the support team.

The water tastes clean and fresh, and the instant hot water feature is extremely convenient. Water flow is strong, the system runs quietly, and the tankless design saves a lot of space under the sink. Expensive, but the quality and features are worth it.

Goodbye, kettle! This system has been a total game-changer for my kitchen. Having purified, near-boiling water on tap instantly is a luxury I didn't know I needed until now. The flow rate is fast, and the smart faucet looks incredibly high-end next to my main sink faucet. One helpful technical detail for future buyers: The RO system doesn't remineralize the water internally (which actually helps protect the heating element from scale buildup). If you want minerals, you can add a remineralization filter to the cold line later or just use mineral drops like I do. It’s a smart design choice, but good to know going in! Some reviews highlight the noise, yes it can be loud at times specially overnight but it hasn't bothered me yet. Highly recommend.

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.

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 just finished installing this beast of a unit. Make no mistake, this is a beast of a unit. I don't think I ever grasped how big the base unit was or how tall the dispenser was. The base unit takes up the entire left side underneath my sink.. probably 25% of the space under there. Maybe more since the pipes and lines intrude on so much. I was installing this in place of an old insinkerator filtration system. The hole was a tad bigger than I think this waterdrop unit wanted so screwing in the nut to hold the dispenser in place wasn't quite as easy as I had a hard time getting it as tight as I thought it needed to be. The hole was a little big and there was not a larger spacer/washer to allow for that. Really the only thing I thought they should have had in the system that wasn't there. After suffering through uninstalling the old unit, installing this waterdrop ro system was really quite easy. I thought the hardest part was drilling the drain hole and then shoving the tube in there. That was hard as the 1/4" hole was too small for the tube and I had to enlarge the hole a little at a time until I could shove the drain tube in. After that, it was really easy. Everything is clearly marked and the tubes go into quick connectors very easily. I did have to read through the setup guide after the install to find out that the system wants to flush for 15 minutes after install to get everything through and before any heating can occur. That's fine. I just didn't know this until I read it. The 60 second flush is normal for any filter so that was expected. So far the unit is pretty awesome. After overcoming the shock of how big it was and getting it finally installed, I think my family will very much enjoy using this. There is no taste to the water and the instant hot water feature is so nice. We had that with the insinkerator until a 3rd tank broke. I wasn't about to get another tank. Hated having to deal with those. It's very early but it seems like this will be everything I expected and maybe even better than I expected. I had mentioned the dispenser Sat pretty high... It sits around 10 inches high off the counter. That's fine. I just wasn't expecting it. Hard to gauge in pictures. But the touch controls and the overall function is really easy and nice. The water coming out seems really fresh. I had some cold and it truly came out cold and it was very refreshing.

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 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!

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.

Water tast better.just like bottles taste.