Westinghouse AMZ-HS120A1G-LP Propane Tankless Water Heater, 5.1 GPM

Westinghouse AMZ-HS120A1G-LP is an outdoor wall-mounted propane tankless water heater listed at up to 5.1 GPM and 120,000 BTU. Its wired controller and claimed 2–4-fixture capacity suit buyers planning a compact whole-home or point-of-use installation, subject to local installation requirements.

At a glance

Outdoor propane unit with listed flow up to 5.1 gpm and heat output of 120000 british thermal units.
The listing says it supports 2–4 fixtures and describes temperature stability of ±1°F. These are manufacturer claims, not independently established performance.
A wired digital controller is described with an adjustable 95°F–158°F range and error-code display.
Listed freeze protection applies to the unit. The manufacturer says external pipes need separate insulation and advises draining the unit if temperatures fall below 32°F without continuous power.

Price

$569.99Save 29%

Reference price: ~~$799.99~~

Price checked: Nov 14, 2026

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Pros and cons

Pros

Outdoor wall-mount design avoids allocating indoor wall space for the heater.
A wired controller and self-diagnosis display are described for temperature adjustment and troubleshooting.
The stated 5.1 gpm flow and claimed 2–4-fixture support may fit modest multi-fixture demand, depending on conditions.

Cons

The listing requires a 120V AC power supply in addition to propane, so it is not a gas-only installation.
Freeze protection does not cover external plumbing, which requires separate insulation.

Technical specifications

12 specifications

Identity
Brand	Westinghouse
Model	AMZ-HS120A1G-LP
Power configuration	gas_powered

Water heating
Listed capacity	16 liters
Flow rate	5.1 gpm
Maximum temperature	158 °F
Heat output	120000 british thermal units
Maximum pressure	150 psi

Dimensions and installation
Mounting type listed	Wall
Dimensions listed	15.5"W x 23.9"H
Depth	7.3 inches

Controls and features
Listed features	5 Years After-Sale Support, CSA Certified, Easy to Install, Remote Control, Temperature Lock

What to know before buying

Listing details to confirm

Listing details are not fully consistent: the title and feature copy identify an outdoor propane unit at 5.1 GPM and 120,000 BTU, while the detail field lists capacity as 16 liters and the power field only says gas-powered. Confirm the selected model’s fuel, capacity and installation requirements before purchase. The claimed ±1°F stability and 2–4-fixture support are listing claims, not independently verified. Professional licensed installation is recommended. The stated freeze protection applies only to the unit. The listing advises fully draining it below 32°F if continuous power is unavailable, and insulating external pipes separately.

What’s in the box

Included

Tankless water heater × 1
User manual
Wire control panel × 1

Who is it for?

A good fit for

Households seeking an outdoor propane tankless heater for a claimed 2–4-fixture setup.
Buyers who want a wired digital temperature controller and can provide a 120V AC connection.

Less suited to

Buyers who need an indoor heater or a system that operates without electrical power.
Installations where the external water lines cannot be protected from freezing.

Westinghouse AMZ-HS120A1G-LP Propane Tankless Water Heater, 5.1 GPM · photo 2 — Additional product photo 2

Customer reviews on Amazon

4.8 / 5 · 16 ratings

5 stars83%83%
4 stars17%17%
3 stars0%0%
2 stars0%0%
1 star0%0%

Aggregate ratings are largely in the top two star categories, but the sample is small and provides no written feedback here. It offers limited evidence about customer experience and does not establish performance, installation ease or reliability for this particular 5.1 gpm outdoor propane configuration.

Frequently asked questions

Does this heater run on propane only?

The title and product copy identify it as propane, but the detail field describes the power source only as gas-powered. The listing also requires a 120V AC supply, so confirm fuel and electrical requirements for the selected model.

Can it supply several fixtures at once?

The listing claims support for 2–4 fixtures and a maximum flow rate of 5.1 gpm. Actual suitability depends on installation and demand, and the stated support is not independently verified.

Does its freeze protection protect the plumbing?

No. The listing says freeze protection applies to the unit only and that external pipes need separate insulation. It advises draining the unit below 32°F if continuous power is unavailable.

What is included?

The stated contents list includes one tankless water heater, one user manual and one wire control panel.