Plumbing code update

The International Code Council (ICC) held its code hearings in late February in Palm Springs, Calif. The hearings, which took place Feb. 18 through March 1, were conducted in two tracks and covered all of the ICC’s family of codes. Notable changes to the plumbing code include increasing the minimum required water pressures at various plumbing fixtures and code changes addressing grease in...


The International Code Council (ICC) held its code hearings in late February in Palm Springs, Calif. The hearings, which took place Feb. 18 through March 1, were conducted in two tracks and covered all of the ICC’s family of codes.

Notable changes to the plumbing code include increasing the minimum required water pressures at various plumbing fixtures and code changes addressing grease interceptor requirements.

During the energy code hearings, a surprise code change occured that may have been under the radar for many in the plumbing industry and for manufacturers of water heaters. These proposed changes in the energy code hearings concerned water heater burner controls.

Water heater ignitions

The committee passed energy code change #EC79-07/08, which requires all gas water heaters to be equipped with pilotless electronic ignitions, and aims to eliminate standing pilots on water heaters. The reason statement said “the water heater accounts for about one-third of the energy use.” The statement went on to say that “pilotless ignitions on gas ranges save about 30% of gas usage over the constantly burning pilot light, so therefore the same energy savings could be attributed to pilotless water heaters.”

The problem with this code change is that it’s similar to comparing apples to oranges. The heat and combustion products from the standing pilot on a stove is a ventless application, and the standing pilot does not contribute to cooking the food, whereas the standing pilot on a vented atmospheric combustion water heater can contribute to maintaining heat within a water heater storage tank. The stove and water heater are two different applications with little relationship to each other. The proponent also said that the payback for installing a pilotless heater would be about 2 years based on 30% energy savings, which may be a flawed statement.

Other testimony from the proponent indicates standing pilots waste energy, which is true for the stove example, and that banning standing pilot lights for gas burners on water heaters would save energy. The problem with this change is that eliminating a standing pilot on an atmospheric water heater will probably not save much energy, because standing pilots generally are used on atmospheric-type equipment. Based on the code change, you may now have an atmospheric-type water heater with an electronic ignition, which means that when the burner is off, the water heater will allow cool air from the floor to draft up through the flues. It makes the water heater act as a water cooler and therefore less efficient.

It appeared the proponent and many of the well-intentioned energy code committee members did not have a thorough understanding of the various construction types for atmospheric versus sealed-combustion burners or flue and draft hood configurations for water heaters. One opponent of the code change testified that the loss of energy from the standing pilot on a water heater was almost negligible, because 75% of the heat from the pilot goes into the water. One code committee member responded, “I want the other 25%.” That comment indicated that he did not understand that the other 25% was going up the flue as exhaust mixed with room air in an atmospheric combustion process and without the standing pilot, nothing but room air will go up the flue, cooling the water even more.

I believe what the proponent was intending to do was eliminate atmospheric combustion water heaters and mandate high-efficiency sealed combustion water heaters, but the proposal was worded poorly and only asked to eliminate standing pilots. With the current wording, someone now can install a spark-ignition on an atmospheric-type water heater, which will be less efficient. Spark-ignition water heaters require an electrical connection, so there will be the cost of an electrical circuit for the water heater and the additional cost for the spark ignition on the water heater.

With this scenario, the cost of construction will go up and the energy savings may be less. There is still an opportunity to address this code change through a comment or challenge process at the ICC’s final action hearings scheduled for late September in Minneapolis. The comment forms and dates will be posted on the ICC Web site at .

Minimum pressures

Another significant code change dealt with the plumbing code and the minimum domestic cold water pressures to be delivered to various plumbing fixtures. Table 604.3 in the International Plumbing Code (see Table) gives minimum required capacities at fixture pipe outlets in gallons per minute and in flowing pressure.

The table conflicted with the minimum pressure and flow requirements in the American Society of Mechanical Engineers (ASME) standard for plumbing fixtures, ASME A112.19.2, “Vitreous China Plumbing Fixtures and Hydraulic Requirements for Water Closets and Urinals,” and the pressure requirements recommended in the American Society of Sanitary Engineering standard for pressure balancing and thermostatic mixing valves and combination pressure balancing/thermostatic mixing valves. The increase in pressures in this table will assure plumbing systems have the proper pressure for safe and sanitary operation, and in a few cases, it may trigger a need for a domestic water booster pump.

Grease traps

During the last code cycle, code requirements were added to change the term grease trap, which was eliminated and a new definition for grease interceptor was included. An addition of the requirements for grease interceptors also was added to meet the Plumbing and Drainage Institute Standard PDI G101 standard or ASME A112.14.3 or ASME A112.14.4. These new requirements left the larger outdoor, gravity-type grease interceptors without code acceptance, and they have been used in many areas for many years.

Many manufacturers of large gravity-type grease interceptors construct these large outdoor-type gravity grease interceptors from concrete, fiberglass, or plastic. A code exception was added this year to allow an exception for interceptors that have a volume greater than 500 gallons and are located outdoors to not have to meet the requirements for the standards listed in the code.

These code changes will appear in the 2009 edition of the International Codes after the final action hearings this fall. Local jurisdictions still must adopt the 2009 code before these code changes can be enforced locally.

Also of note, the International Assn. of Plumbing and Mechanical Officials will have its code hearings for the Uniform Plumbing Code and Uniform Mechanical Code May 5-9, 2008, at the Adams Mark Hotel in Denver.

The ICC proposed code changes and the results can be viewed on the ICC’s Web site at .

Type of fixture

Old minimum Flow pressure (psi)

New minimum Flow pressure (psi)

Bathtub, with ASSE 1016 or 1070 valve


20 psi

Bidet, with ASSE 1070 valve


20 psi

Shower, with ASSE 1016

20 psi

20 psi

Urinal, flushometer valve

15 psi

25 psi

Water closet blowout, flushometer valve

25 psi

45 psi

Water closet, flushometer tank

15 psi

20 psi

Water closet, siphonic, flushometer valve

15 psi

35 psi

Water closet, tank, close coupled

8 psi

20 psi

Author Information

George is president of Ron George Design & Consulting Services ( ), which offers plumbing design and code consulting service, 3-D CAD design, and construction coordination services and forensic investigations of mechanical system failures and litigation support.


The ICC code family includes:

• International Building Code

• International Fire Code

• International Wildland Urban Interface Code

• International Energy Conservation Code

• International Existing Building Code

• International Fuel Gas Code

• International Mechanical Code

• International Plumbing Code

• International Private Sewage Disposal Code

• International Property Maintenance Code

• International Residential Code

• International Zoning Code

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