The 2021 cycle for the ICC international codes has begun. Every technical change to the Plumbing, Mechanical, and Fuel Gas Code has already been submitted for the 2021 edition.

Once again, hot water is a major topic of many of the code changes. The issues surrounding hot water are: scalding, emergency equipment and Legionnaires’ disease. The proposed code changes deal with the temperatures of hot water and the means to regulate that temperature.

The current International Plumbing Code identifies hot water as having a temperature of 110° F or higher. Tempered water is 85°-110°. Should the hot water temperature be raised to 120° minimum? This will be part of the discussion before the committee. The temperature ranges relate to helping to control Legionella bacteria growth.

The new ASSE standards for water heaters are being proposed as a means of controlling the temperature of the hot water. The three standards would provide equivalency to temperature- limiting and -controlling valves. Currently, the code only recognizes ASSE 1070 (ASSE 1070/ASME A112.1070/CSA B125.70) or ASSE 1016 (ASSE 1016/ASME A112.1016/CSA B125.16) for regulating the maximum temperature of hot water. The ASSE 1084 water heater standard is equivalent to an ASSE 1070 valve, whereas the ASSE 1082 water heater standard is equivalent to an ASSE 1017 valve. The difference is that an ASSE 1070 valve will stop the flow of water when the temperature exceeds the maximum temperature setting, while an ASSE 1017 valve will allow water to continue to flow.

There are other proposed changes that would allow the use of an ASSE 1017 valve for controlling the maximum temperature of hot water. This would be allowed for regulating the maximum hot water temperature to showers, bathtubs, shampoo sinks, foot baths and lavatories.

For emergency showers, eye wash and face wash systems, the code references ASSE 1071 as the valve for regulating the temperature of tepid water. However, this requirement only applies when there is a supply of hot and cold water to the fixtures. A change will allow the use of an ASSE 1085 water heater to serve emergency fixtures. The ASSE 1085 water heater standard is based on being equivalent to ASSE 1071.

Each of the proposed changes indicate ASSE 1082, 1084 and 1085 are draft standards. However, ASSE hopes to have these standards finalized before the end of the code-change cycle. If the standards are not completed, their acceptance will be delayed until the 2024 edition of the International Plumbing Code.


Leak catcher

Intermixed with the water heater standards is a proposal to require every water heater to have a pan if a leak could result in damage to the building. The current code only requires pans for storage-type water heaters. This requirement could apply to very small instantaneous water heaters that are commonly installed with a residential kitchen sink. If a pan is required for these types of water heaters, it could signal the end of their use. The installation of a pan and connection to a drain probably would more than double the cost of the installation.

Another Legionnaires’ disease change proposed will be a requirement to comply with ASHRAE 188. This standard has been proposed in the past with little success. However, the change this cycle will be directed to the design engineer regarding the design of water-distribution systems.

Other water code changes involve water conservation. Flow rates for showers, kitchen sinks and lavatories will be debated. In addition, flush volumes for water closets and urinals are up for discussion. Add to that discussion, a limitation on the amount of water a water-supplied trap primer can use in a one-year period of time.

Water-closet compartments are subject to a few changes to the Plumbing Code and the Building Code. One proposal will require full height compartments. Basically, it would result in individual rooms for a water closet. A lavatory could be added to the compartment.

This change is somewhat of a follow-up to the change requiring single-occupant toilet rooms to be marked as available for both men and women. The movement is toward a general area where men and women select the compartment to use without having women’s rooms and men’s rooms. Some European countries already have converted to allowing this design.

The difference is that one of the changes would require individual compartments in all situations. That would be a drastic change in the design of buildings regarding the location of plumbing fixtures.


Disposer dilemma

Food-waste disposers and grease interceptors will be up for discussion again. The 2018 International Plumbing Code prohibits a food-waste disposer from discharging through a grease interceptor. Plumbing engineers have asked for an allowance of a small-size food-waste disposer on two-compartment and three-compartment sinks. The concept is to clear the remaining food particles after a wash cycle through a disposer. However, these sinks connect to grease interceptors.

The proposal is to limit the size of such food-waste disposers to 1 hp. Thus, the full use of a commercial disposer would be located elsewhere in the food-handling establishment. But a small food-waste disposer would be allowed to be used to remove small quantities of waste.

Also related to food-waste disposers is a proposal to allow a disposer to connect to a combination waste and vent system. The International Residential Code-Plumbing Section allows food-waste disposers to connect to combination waste and vent systems. However, the International Plumbing Code prohibits such an installation. The code change will result in the Residential Code and Plumbing Code being consistent by allowing such a connection.

One of the many complaints I have heard from plumbing engineers is that code development has become controlled by the professionals in the business (code and standard consultants and various associations). It is nearly impossible for a lay person to propose a code change when the 2018 codes are only published a few weeks before the deadline for submitting code changes to the next edition. This is true and something that the model codes need to consider.

You can download all of the proposed code changes on the ICC website, either or The first hearing will be held from April 14-25 in Columbus, Ohio.