The ANZZI WH-AZ021-M3 is an ENVO Atami high-capacity tankless electric water heater rated 21 kW at 240V, built for whole-home application: a family home where a shower and a sink may run together. It replaces a storage tank with a wall-mounted unit that heats water as it flows, and hot water volume is not limited like in tank-style units.
Whole-Home Hot Water Without a Tank
An ANZZI tankless electric water heater does not preheat or store water. When a tap or shower opens and the flow passes the activation rate (0.85 GPM on the 3/4" Atami models), the WH-AZ021-M3 turns on and heats the water passing through; when the flow stops, so does the heater. There is no preheating and no standby heat loss: water is not stored and reheated, and the design avoids tank limescale build-up for a longer life.
Set the outlet temperature on the LED display from 86°F to 125°F, in Fahrenheit or Celsius, and the heater recalls your last setting. Twenty seconds after the water stops, the screen goes into energy saving mode.
Power and Protection at 21 kW
Over-temperature protection begins lowering the output if the water reaches 144°F, and the water and electrical systems are isolated from each other inside the unit. The manual warns that after a pause the first water can be very hot, so let it settle before stepping into the shower.
Because of its size, the WH-AZ021-M3 draws 21000W at 240V, a rated current of 87.5A, and needs three separate circuits: three 30A double-pole breakers with 3 x 8 AWG minimum wire. Check that your electrical service can carry that load before you order. Water connections are 3/4" NPT using stainless steel flexible hoses or copper, never PVC, CPVC or plastic, and maximum water pressure is 87 psi.
Compact for Its Capacity
The Atami case measures 3.54" deep, 15.16" high and 10.24" wide and weighs 14.31 lbs, and the tankless design fits tight spaces like cabinets and closets. It mounts vertically with the fittings pointing down, and it is ETL certified and listed. Plan for 12" of clear space above and below it and 6" in front and to each side.
For whole-home application, the ANZZI WH-AZ021-M3 tankless electric water heater gives hot water on demand at 21 kW from a compact, wall-mounted case.
Features
21 kW Whole-Home Capacity
At 21000W, the WH-AZ021-M3 is sized for a family home where a shower and a sink may run together, heating water continuously while it flows.
Clear Electrical Requirements
It draws 87.5A at 240V on three 30A double-pole breakers with 3 x 8 AWG minimum wire, the figures a licensed electrician needs to confirm your panel capacity.
Endless Supply, No Standby Loss
With no tank to keep hot, energy is used only while water is flowing, and hot water does not run out after a long shower.
86°F to 125°F With Memory
Set the temperature on the LED display in Fahrenheit or Celsius, and the heater recalls the last setting for the next use.
Over-Temperature Protection
If the outlet water reaches 144°F, the over-temperature protection automatically cools the output down to a safe level.
Water and Electric Separation
ANZZI isolates the flowing water from the electrical system inside the unit (water/electric separation).
3/4" NPT Connections
Full 3/4" NPT inlet and outlet carry whole-home flow, using stainless steel flexible hoses or copper.
Wall-Mounted 3.54" Deep Case
At 3.54" x 15.16" x 10.24" and 14.31 lbs, it is a wall-mounted unit with no tank, for tight spaces like cabinets and closets.
ETL Certified and Listed
ANZZI lists the heater series as ETL certified and listed, and this model is rated 21 kW at 240V, 60 Hz.
Specifications
-
Model: WH-AZ021-M3
-
Dimensions: 3.54" D x 15.16" H x 10.24" W
-
Weight: 14.31 lbs
-
Power: 21 kW (21000W)
-
Voltage: 240V, 60 Hz
-
Rated Current: 87.5A
-
Circuit Breakers: three 30A double-pole breakers
-
Minimum Wire Size: 3 x 8 AWG
-
Activation Flow: 0.85 GPM
-
Temperature Range: 86°F to 125°F
-
Over-Temperature Protection: 144°F
-
Maximum Water Pressure: 87 psi
-
Water Connections: 3/4" NPT
-
Installation: Wall mount, vertical, fittings down
-
Certifications: ETL certified and listed
-
Series: ENVO Atami
-
Warranty: Limited lifetime (register within 90 days)
What's Included
- WH-AZ021-M3 tankless electric water heater (supplied without cable)
- Installation kit
- Installation and operation manual
Sold separately: Power cable and wiring (the unit ships without cable), Circuit breakers
Installation & Care
Installation
Hardwired on three dedicated, grounded 240V circuits (three 30A double-pole breakers, 3 x 8 AWG minimum copper wire) with a disconnect provided by a qualified electrician; ANZZI recommends a licensed and qualified electrician. Mount it vertically with the fittings pointing down in a dry area that cannot freeze, with 12" clear above and below and 6" in front and to the sides. Connect 3/4" NPT stainless flexible hoses or copper (no PVC or CPVC), let water flow through before switching on the breakers, and fit a pressure reducing valve above 150 psi inlet pressure. Fit a filter ahead of the inlet and a softener on hard water, and an expansion tank where a check valve closes the system. Professional installation is highly recommended.
Care
ANZZI's manual: shut off power at the breaker before any maintenance and let hot water drain safely. Periodically clean the inlet strainer (unscrew the inlet nipple, replace the filter, refit with its washer), the faucet aerator and the shower head so scale does not choke the flow. Wipe the case with a soft, damp cloth and mild soap only; never spray it with water or use abrasive or solvent cleaners. If the unit sits unused through winter, drain it completely to prevent freezing.
Resources
Shipping, Returns & Warranty
ANZZI ships this item from the SW Corp warehouse by UPS, FedEx or USPS, usually within 1 to 2 business days of your order. Shipping is free within the lower 48 states on orders of $101 or more (orders under $101 ship for a flat $15); for Alaska or Hawaii, contact us before you order. You'll get tracking by email as soon as it ships.
Inspect the packaging and the product before you sign. Note any damage or shortage on the delivery receipt, then email photos to support@mycleansupplies.com within 48 hours of delivery so the freight claim can be filed. Damage reported after 48 hours can't be claimed.
Unused ANZZI products in their original packaging can be returned within 21 days of delivery. Ask us for a return authorization before you ship. You pay the return shipping, which for a freight item means the freight cost, and a 20% restocking fee is deducted along with payment processing fees. Installed, used or damaged products and special-order items can't be returned.
ANZZI warrants this water heater to the original purchaser against defects in materials and workmanship for its lifetime, for residential use, and replaces a defective product or part free of charge. Register it at anzzi.com/register within 90 days of delivery to activate the warranty, and report any surface damage within 5 days of delivery, before installation. Shipping, handling and labor costs, commercial use, improper installation or maintenance, misuse, hard-water or mineral deposits and corrosive cleaners are not covered.
Warranty claims. Call ANZZI at 1-844-442-6994 (1-844-44-ANZZI) with your proof of purchase to submit a claim and get a return authorization (RMA). Register the product at anzzi.com/register within 90 days of delivery, or the warranty is not active. Contact us with your order number if you would like help with the claim.
About ANZZI
ANZZI is a kitchen and bath brand from SW Corp, a Miami, Florida company that also makes SteamSpa and MediTub. It designs freestanding and walk-in bathtubs, shower doors and bases, faucets, sinks, toilets and kitchen fixtures, bringing European bath design to North American homes.
The Atami comes in 18 kW (WH-AZ018-M3), 21 kW (WH-AZ021-M3), 24 kW (WH-AZ024-M3) and 27 kW (WH-AZ027-M3). For a single sink or a single shower, ANZZI's ENVO Ansen (3.5 kW, 6 kW) and Arima (11 kW, 14.6 kW) are the smaller options.
