The Faucet That Turns Water Into an Appliance System.
Zip HydroTap is what happens when the kitchen faucet stops being plumbing and becomes infrastructure. The current Celsius Plus All-in-One with Pull-Down Sprayer can deliver filtered boiling, chilled and sparkling water, ordinary hot and cold water, and a pull-down spray head from a single fixture. The elegant part is above the counter. The interesting part is the compact thermal, filtration, carbonation and control system hiding beneath it.
By Dr. Rob Urban · On boiling water storage, refrigeration, carbonation, 0.2-micron filtration, under-cabinet engineering, energy management, kitchen workflow and why the most ambitious faucet in the room is not really a faucet at all
First, the current-product check
The strongest current HydroTap for this story is the Celsius Plus All-in-One with Pull-Down Sprayer, not an older Arc, Cube or original Celsius configuration.
Zip's current U.S. residential range identifies the Celsius Plus All-in-One with Pull-Down Sprayer as a new top-end HydroTap option. It combines filtered boiling, chilled and sparkling water with ordinary unfiltered hot and cold water, then adds an integrated retractable spray hose so the same fixture can serve as the kitchen's primary faucet rather than a secondary luxury tap.
That matters because the story has always been larger than “instant boiling water.” The mature HydroTap concept is consolidation. A kettle, filtered-water faucet, chilled-water dispenser, sparkling-water machine and ordinary mixer faucet are compressed into one user interface supported by an under-counter command center.
The current U.S. system runs on 110 to 120 volts and a 15-amp supply. Zip's spec sheet lists a 0.2-micron integral filter, a dedicated carbon-dioxide cylinder for sparkling water, a command center roughly 13.3 inches wide, 18.2 inches deep and 13.1 inches high, and a separate hose-management assembly for the pull-down sprayer.
The faucet itself is twenty inches tall, with a spray hose that can extend up to roughly 35.5 inches. It is not a small retrofit accessory. It is a deliberately integrated kitchen system.
The faucet is the user interface
The machine is under the sink.
Look only at the tap and the HydroTap can seem almost magical. Press a control and boiling water appears. Press another and chilled water arrives. Ask for sparkling and the same fixture delivers carbonated water. Move the lever and it behaves like a normal mixer. Pull the head down and it becomes a sink sprayer.
There is no magic. There is a compact utility plant hidden in the cabinet.
The command center filters incoming potable water, maintains a hot reservoir, refrigerates another water path, manages carbonation, monitors temperatures, controls valves and protects the system from unsafe conditions. The faucet communicates the user's choice, but the heavy engineering happens behind the cabinetry.
This division of labor is why HydroTap feels so clean above the counter. The product does not try to miniaturize a heater, chiller and gas system into the spout. It relocates complexity to the space where complexity can be ventilated, serviced and connected properly.
The result is very similar to good industrial system design. Put sensing, thermal control and utilities in the equipment enclosure. Present the operator with a simple interface.
The beautiful faucet is almost the least technically interesting component.
Boiling water is a storage problem as much as a heating problem
Instant means the energy was spent before you asked for the water.
A conventional kettle heats water on demand. That is simple and efficient when use is occasional, but it introduces waiting time because the water begins near room temperature and must absorb enough energy to approach boiling.
An instant boiling-water system changes the timing. It keeps a reservoir of water hot so that the user experiences essentially no warm-up delay. The technical challenge becomes maintaining that temperature safely while limiting standby energy losses.
Heat naturally leaks from a hot tank into the surrounding cabinet. Better insulation slows that transfer, but cannot eliminate it. The system therefore cycles heating elements as needed to maintain the stored water within its target band.
Zip's current G5 command center adds configurable energy-saving behavior including timers and sleep modes. The idea is straightforward: a system that knows the kitchen is unused overnight or on certain days does not need to maintain full readiness every minute of the year.
This makes instant boiling water an interesting trade between convenience and standby consumption. You spend some energy maintaining readiness in exchange for eliminating the repeated wait associated with kettle heating.
For a household that makes tea, coffee, blanching water, oatmeal, stock, noodles or cooking water repeatedly through the day, that convenience can become part of the kitchen's rhythm rather than a party trick.
Chilled water brings refrigeration under the sink
The system is carrying away heat every time it serves a cold glass.
Cooling water is thermodynamically the reverse of heating it. The command center does not create “cold.” It uses a refrigeration cycle to move heat from the water into the surrounding environment.
A refrigerant circulates through a compressor, condenser, expansion device and evaporator. At the evaporator, the refrigerant absorbs heat from the water circuit. The compressor raises refrigerant pressure so that this heat can later be rejected through the condenser into cabinet air.
This is why ventilation matters. A chilled-water system hidden inside cabinetry must still move heat somewhere. Zip's current G5 design uses air cooling and an integrated front vent intended to improve airflow and efficiency.
Zip also emphasizes that its air-cooled approach is water efficient because it does not consume potable water merely to reject heat. The product page describes the HydroTap as 100 percent water efficient in the sense that cooling does not require a continuous drain of cooling water.
The current G5 generation also moved to R290 refrigerant, a hydrocarbon refrigerant with much lower global-warming potential than many legacy refrigeration gases. Zip says the change reduces the system's refrigerant-related global-warming potential by 95 percent compared with its preceding HydroTap refrigerant.
The chilled-water button hides a refrigerator. The elegant part is that the refrigerator has been designed to disappear into the cabinet without wasting water to cool itself.
Heat leaves the water
The evaporator side of the refrigeration circuit pulls thermal energy from the chilled-water path.
Compressor does the work
The refrigeration system raises pressure and circulates refrigerant so absorbed heat can be transported.
Cabinet airflow matters
The condenser releases that heat into surrounding air, making proper command-center ventilation part of system performance.
Sparkling water is dissolved gas under pressure
Carbonation works better when the water is cold, which makes refrigeration part of the bubble story.
Carbon dioxide dissolves into water more readily at lower temperatures and higher pressure. The HydroTap exploits both. It chills the water, introduces beverage-grade carbon dioxide from a dedicated cylinder and maintains the conditions needed to produce sparkling water on demand.
When that pressurized carbonated water exits the faucet, pressure falls toward atmospheric conditions. Dissolved carbon dioxide becomes less stable in solution and begins forming bubbles. That familiar fizz is the gas leaving the liquid.
This is why good sparkling-water systems care about temperature before the carbonation step. Colder water can hold more dissolved CO2 at a given pressure, helping create a more persistent sparkle.
The current Celsius Plus All-in-One uses a dedicated sparkling outlet geometry and an optimized aerator in the broader G5 design. Zip's U.S. system can use 1.5-pound beverage-grade CO2 cylinders, with a larger 5-pound option where cabinet space permits.
The important design idea is not simply “add gas.” Carbonation becomes a coordinated function of filtration, chilling, gas regulation and controlled dispensing.
That coordination is why an integrated system can feel different from countertop soda makers. There is no bottle to chill first, no cylinder to screw into a countertop machine every time and no separate appliance occupying workspace.
Every premium water system eventually becomes a filtration story
Zip's current MicroPurity system is rated at 0.2 microns and now carries certified PFAS-reduction claims.
The current HydroTap platform uses Zip's MicroPurity filtration. Zip describes the current 0.2-micron filter as certified to reduce eight contaminant categories, including chlorine taste and odor, sediment, lead, asbestos, microplastics, cysts such as Cryptosporidium and Giardia, bacterial growth and PFAS.
The important word is “reduce.” No residential point-of-use filter should be described casually as making every possible water source safe. HydroTap is designed for potable incoming water, and performance depends on the installed filter, water chemistry, flow conditions and maintenance interval.
Zip's current documentation says its MicroPurity size 1 and 1.5 filters are independently certified under relevant NSF/ANSI standards, including 42, 53 and 401, and states an average 99.4 percent reduction claim for total PFAS on the certified filter models.
For the U.S. residential command center, the spec sheet lists filter replacement at 1,100 gallons or twelve months, whichever comes first.
The filtration layer matters for more than health-related claims. Chilled water, tea and sparkling water are unusually revealing of taste and odor. Removing chlorine taste, sediment and other unwanted characteristics changes the sensory experience of every state the HydroTap produces.
This is where the machine begins to make sense as a single system rather than five separate faucet tricks. The same incoming supply is conditioned before being routed toward boiling, chilling or carbonation.
The real luxury is removing intermediate steps
HydroTap is compelling because it collapses little kitchen workflows that people normally accept without noticing.
Tea usually means filling a kettle, waiting and pouring. Sparkling water means buying bottles or loading a countertop carbonator. Chilled filtered water often means a refrigerator dispenser or pitcher. Filling a stockpot means using the sink, then waiting for the cooktop to supply the rest of the heat. Cleaning the sink means pulling a spray head from the primary faucet.
The Celsius Plus All-in-One with Pull-Down Sprayer folds those actions into one fixture. Filtered boiling, chilled and sparkling water are selected from the touch interface. Normal hot and cold water are controlled as expected. The pull-down head handles rinsing and sink work.
That kind of consolidation can look excessive if each function is considered independently. A kettle is cheaper. A countertop carbonator is cheaper. A refrigerator can dispense cold water. A normal faucet already supplies hot and cold.
But luxury products often justify themselves through friction removed across many repeated actions rather than through one capability that cannot be reproduced another way.
The better comparison is not “does this beat a kettle?” It is “what happens when the kitchen stops needing a kettle, bottled sparkling water, a separate filtered tap and a secondary faucet for prep?”
This is why the product fits naturally into high-end kitchen and remodeling projects. The under-counter planning is substantial, but the reward is visual and operational simplification above the counter.
The pull-down sprayer is more consequential than it sounds
It turns HydroTap from a specialty fixture into the primary faucet.
Earlier multi-function water taps were often installed beside a conventional kitchen faucet because the specialty tap did not fully replace ordinary sink work. That creates visual duplication and consumes deck space.
The Celsius Plus All-in-One with Pull-Down Sprayer changes the equation by incorporating a retractable spray hose into the same fixture that handles the five water states.
Zip's U.S. specification allows the spray nozzle to extend up to roughly 35.5 inches. The system uses a separate hose-management assembly mounted below the counter so the hose can retract cleanly without tangling around the command center, drain plumbing or disposal.
This is a deceptively hard design problem. Under-sink cabinets are already hostile spaces filled with traps, supply lines, waste disposals, filters and stored household products. Add a chiller, hot tank, CO2 cylinder and moving hose, and packaging becomes a three-dimensional coordination exercise.
Zip's solution is interesting because the visible product becomes simpler while the hidden installation becomes more disciplined.
That is often the price of good industrial product design: complexity does not vanish. It gets moved somewhere the user does not have to manage it every day.
The cabinet is the real installation site
This is not a faucet you swap in during lunch.
The current U.S. Celsius Plus All-in-One with Pull-Down Sprayer requires both hot and cold water supplies, a potable cold-water feed, a 110 to 120-volt 15-amp electrical supply, carbon dioxide, drainage and enough cabinet volume for the command center and hose-management system.
Zip lists a minimum 30-inch-wide by 24-inch-deep cabinet for the pull-down configuration. The command center itself is about 13.3 by 18.2 by 13.1 inches, and Zip specifies air-clearance requirements around it. The hose-management mechanism adds another component that must sit directly enough beneath the faucet to allow the sprayer to retract smoothly.
This is exactly why HydroTap is best considered during kitchen design rather than as an afterthought. Sink depth, disposal location, drain placement, electrical outlet, ventilation and cabinet storage all compete for the same volume.
There is also maintenance. Filters need replacement. CO2 cylinders eventually empty. The chiller needs airflow. Service access matters. A beautifully fitted command center becomes annoying if a contractor has boxed it behind cabinetry that makes routine maintenance difficult.
The product therefore rewards coordination between plumbing, electrical, cabinetry and appliance planning. This is closer to specifying a built-in appliance than choosing a faucet finish.
That complexity is real and should not be hidden by the luxury marketing. The polished spout is the final visible centimeter of a system that may occupy a meaningful portion of the sink base.
Energy management is part of the modern generation
A machine that keeps water hot and cold all day has to know when not to work.
The HydroTap proposition depends on readiness. Boiling water must be hot before the user asks for it. Chilled water must already be cold. That creates unavoidable standby loads that a simple conventional faucet does not have.
Zip addresses this through insulation, efficient refrigeration, timers, sleep modes and system controls. Current G5 materials describe three energy-saving modes, including programmable on-off timing and a two-hour sleep mode.
This is the right engineering direction because the ideal system is not one that never consumes power. It is one that aligns power consumption with actual demand.
An office can power down outside working hours. A household can allow the unit to sleep overnight. A command center can maintain service temperatures during active windows and reduce unnecessary cycling when nobody is likely to use it.
The 2024 G5 revision also moved to R290 refrigeration and redesigned front ventilation. Zip says the refrigerant change reduces global-warming potential by 95 percent relative to the previous refrigerant used in HydroTap.
None of this makes instant boiling and chilled water free. It makes the convenience more technically responsible than simply leaving an old resistance heater and inefficient chiller running without intelligence.
Zip spent decades removing the wait from water
The HydroTap is the logical endpoint of a company that began with water heaters in 1947.
Zip was founded in Sydney in 1947 as a manufacturer of kitchen and bathroom water heaters. Michael Crouch acquired the company in 1962 and pushed it toward increasingly specialized instant-water products.
By the 1960s, Zip was making boiling-water equipment for canteens, factories and office kitchens. The company says it installed the world's first under-sink pressurized boiling-water tap in 1970, then continued with on-wall instant boilers and the Zip Tea Tap through the following decades.
The decisive transition came in 1996 with an air-cooled under-bench filtered instant system that evolved into HydroTap. By 2012, Zip introduced the All-In-One concept combining filtered boiling, chilled and sparkling water with ordinary hot and cold service through a single outlet.
Design became increasingly central. Arc, Cube and Elite styles appeared in 2015. Culligan International acquired Zip in 2017, expanding the brand's global reach. The current G5 platform arrived as the fifth generation, with the latest refrigerant and airflow changes appearing in 2024.
The Celsius Plus All-in-One Pull-Out or Pull-Down configuration is the mature expression of that history because it closes the last obvious gap: normal sink functionality. Zip introduced the pull-out concept in 2023, and the current U.S. version remains the flagship primary-faucet interpretation of HydroTap.
Zip is founded in Sydney manufacturing water heaters for kitchens and bathrooms.
Zip says it installs the world's first boiling-water tap using an under-sink pressurized cylinder.
An air-cooled under-bench filtered instant water system establishes the architecture that evolves into HydroTap.
HydroTap All-In-One combines filtered boiling, chilled and sparkling water with ordinary hot and cold service.
Culligan International acquires Zip Water, supporting broader international expansion.
Zip introduces the All-In-One pull-out concept with five water types and an integrated retractable sprayer.
G5 evolves with R290 refrigeration, revised airflow and the current Celsius Plus family remaining at the top of the residential range.
The most interesting engineering decision is consolidation
Each function is ordinary. Making them coexist is not.
Heating water is old technology. Refrigerating water is old technology. Carbonating water is old technology. Filtering water is old technology. Mixing hot and cold water is old technology. Pull-down spray heads are old technology.
The difficulty appears when all of those systems have to share one cabinet, one faucet body and one daily user experience.
Boiling water requires serious safety controls. Chilled water requires heat rejection. Carbonation requires pressurized gas and cold water. Filtration adds pressure drop and scheduled maintenance. A pull-down hose needs unobstructed travel. Ordinary hot and cold service still has to work like a normal faucet.
Every subsystem competes for space, plumbing paths, power, service access and user-interface attention.
This is why mature products often look simpler than first-generation products. The engineering team has learned where complexity can be buried and where it cannot.
The current HydroTap is not impressive because any individual subsystem is unprecedented. It is impressive because the user can interact with all of them without thinking like a facilities engineer.
There is a sustainability argument, but it needs to be framed carefully
The strongest case is reducing disposable packaging and avoiding wasteful cooling methods, not pretending convenience has no energy cost.
Zip emphasizes that HydroTap can reduce reliance on bottled still and sparkling water. That claim is directionally sensible: a plumbed filtered and carbonated system can replace repeated purchases of individual bottles or cans, especially in high-use homes and offices.
The current commercial materials also promote lifecycle reductions in single-use plastic bottles, while the residential platform uses air-cooled refrigeration instead of water-cooled chilling that would consume water simply to reject heat.
But a fair analysis should also acknowledge the system's embodied materials, electricity consumption, replaceable filters and CO2 cylinders. Convenience has infrastructure.
The better sustainability question is comparative. What does the HydroTap replace in a particular household? Bottled sparkling water shipped long distances? A kettle boiled repeatedly? A refrigerator dispenser? A countertop carbonator? A separate filtered tap?
The answer will vary.
What Zip has clearly improved in the latest G5 generation is the refrigeration side. R290 has a dramatically lower global-warming potential than many older refrigerants, and the redesigned command-center airflow aims to improve thermal efficiency.
That is meaningful engineering progress even if it does not turn a luxury appliance into an energy-neutral object.
Why it goes in the digital time capsule
Because it captures the moment the faucet became a programmable utility endpoint.
The Things Worth Wanting collection is interested in products that make an everyday object reveal a much larger technological system.
HydroTap does that beautifully.
A faucet used to be a valve at the end of a pipe. Hot water arrived because a separate heater somewhere else in the building had already done the work. Cold water arrived at whatever temperature the mains delivered. If you wanted filtered water, chilled water or sparkling water, those were separate products.
The current Celsius Plus All-in-One with Pull-Down Sprayer treats the faucet as a service terminal. The water has already been filtered, heated, refrigerated or carbonated according to the selected mode. Electronics arbitrate the request. Safety controls govern boiling delivery. A dedicated command center maintains several thermal states at once.
That makes the kitchen sink feel less like plumbing and more like an appliance network.
I also like the historical continuity. Zip did not arrive at this product by suddenly deciding luxury kitchens needed more buttons. The company has been trying to shorten the distance between “I want water like this” and “here it is” since the middle of the twentieth century.
Boiling water without the kettle wait. Chilled water without the refrigerator. Sparkling water without the bottle. Filtered water without the pitcher. Ordinary sink work without a second faucet.
That is a very specific vision of convenience.
It requires money, cabinet space, careful installation and ongoing maintenance. It is not sensible for every kitchen, and pretending otherwise would miss the point.
The reason it belongs here is that Zip took one of civilization's oldest household interfaces and asked how many water states could be made available instantly from the same place.
The answer is now five, plus a pull-down sprayer.
At that point, calling it a faucet starts to undersell the machine.
A few practical questions
About the current Zip HydroTap Celsius Plus All-in-One with Pull-Down Sprayer
What is the current top residential Zip HydroTap for this story?
The Celsius Plus All-in-One with Pull-Down Sprayer is the strongest current residential expression because it combines filtered boiling, chilled and sparkling water with ordinary hot and cold water and an integrated retractable spray head.
Does the HydroTap really make boiling, chilled and sparkling water from one faucet?
Yes. The filtered drinking-water functions are handled by the under-counter command center, while the same fixture also provides unfiltered hot and cold mixer water.
What kind of filtration does the current system use?
Zip specifies 0.2-micron MicroPurity filtration. Current certified filter models are rated for reduction of several contaminant categories including lead, sediment, chlorine taste and odor, microplastics and PFAS.
Does it require CO2?
Yes. Sparkling-water operation requires a beverage-grade carbon-dioxide cylinder and regulator. U.S. documentation lists 1.5-pound cylinders and an optional 5-pound cylinder where cabinet space allows.
How much cabinet space does it need?
The U.S. pull-down configuration calls for a minimum cabinet roughly 30 inches wide and 24 inches deep, with additional clearance around the command center for airflow and space for the hose-management system.
Does the current G5 system use a newer refrigerant?
Yes. Zip's current G5 platform uses R290 refrigerant and says this reduces refrigerant global-warming potential by 95 percent compared with the preceding refrigerant used in HydroTap.
Is the pull-down sprayer separate from the drinking-water outlet?
The functions are integrated into the same primary faucet assembly, with a retractable hose-management system beneath the counter supporting the spray head.
Is this a simple DIY faucet replacement?
No. The system requires plumbing, power, ventilation, filtration, carbonation hardware and careful cabinet planning. It is better treated like a built-in appliance installation than a standard faucet swap.