Does a Coffee Maker Require a Backflow Preventer, Vent, and Drain for Commercial Jobs?

Markham Jarrett, a Plumbing Designer with Spectrum Design in Martinsville, Virginia, recently wondered if a coffee maker would have to follow the same code requirements as other beverage-dispensing machines, so he asked our experts on ASPE Connect: Does a coffee maker require a backflow preventer, vent, and drain for commercial jobs?

The purpose of a backflow preventer is to prevent cross-contamination between the potable system and any other source of liquid that might contain a contaminate. These contaminates could be a nascence, a low hazard, or a serious hazard. While coffee is not considered a hazard in a potable water system, it does not belong there. Additionally, coffee pots occasionally get chemically cleaned, which could be a serious hazard if those chemicals were to enter the potable system.

What Does the Code Say?

2018 International Plumbing Code (IPC) Section 608.17.1.2, Coffee makers and non-carbonated drink dispensers, says: “the water supply connection to each coffee machine and each non-carbonated beverage dispenser shall be protected against backflow by a backflow preventer conforming to ASSE 1022 or ASSE 1024, or protected by an air gap.”

What Are the Different Types of Backflow Preventers?

ASSE 1022 backflow preventers are specially designed for carbon dioxide exposure. They are acceptable for use with carbonated drink dispensers, non-carbonated drink dispensers, and coffee machines. However, coffee machines and non-carbonated beverage dispensers can be connected to the potable water supply using ASSE 1024 backflow preventers, as introduced in the 2018 IPC.

An ASSE 1022 device has a vent opening that leaks water when the downstream check valve of the device fails. The leaking water is required to drain indirectly to a safe point of discharge.

An ASSE 1024 device does not have a vent opening and is not required to be drained.

The IPC also allows dual check valves conforming to ASSE 1024, which do not have a vent and subsequent drain. A double check valve could also be protective against Legionella, especially if the supply to the coffee maker is a line that tees off from the supply to an ice machine.


The first and primary responsibility of designers and engineers is to protect the public’s health, safety, and welfare, so when in doubt, provide backflow protection.

Can You Help?

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