TITLE 77: PUBLIC HEALTH
CHAPTER I: DEPARTMENT OF PUBLIC HEALTH
SUBCHAPTER r: WATER AND SEWAGE
PART 890 ILLINOIS PLUMBING CODE
SECTION 890.1220 HOT WATER SUPPLY AND DISTRIBUTION
Section 890.1220 Hot Water Supply and Distribution
a) All water heaters shall comply with the requirements of Appendix A, Table A, (Approved Standards for Plumbing Appliances/Appurtenances/Devices), and ASHRAE 90 Standards. Hot water storage tanks shall meet construction requirements of ASME, AGA, or UL listed in Appendix A, Table A (Approved Standards for Plumbing Appliances/Appurtenances/Devices), as appropriate. Hot water supply boilers with heat input in excess of 200,000 BTU per hour, water temperature in excess of 200° F, or capacity in excess of 120 gallons must also comply with the requirements of the Boiler and Pressure Vessel Safety Rules and Regulations (41 Ill. Adm. Code 120). Smaller water storage tanks that are not subject to ASME requirements shall be constructed of durable materials and constructed to withstand 150 p.s.i. (See Appendix I, Illustrations L and M, for examples of typical water heater installations.)
1) All equipment used for heating and storage of hot water shall bear the marking of an approved testing agency certifying that it has been tested and approved and listed as meeting the requirements of the applicable standard. Listing by Underwriters Laboratories, American Gas Association or National Board of Boiler and Pressure Vessel Inspectors, or the ASME Standard shall constitute evidence of conformance with these standards.
2) A solar-heated system shall use a double-walled heat exchanger which is exposed or vented to the atmosphere between the walls.
3) Heat exchangers may be of single wall construction if a non-toxic transfer fluid with no conditioning chemicals in the system is used, or if a pressure gradient monitor system is installed to isolate the heat exchanger from the potable water system. If pressure on the potable water side reaches a pressure less than 10 p.s.i. above the toxic transfer fluid pressure, an audible alarm shall be activated.
4) Heat exchangers using a toxic transfer fluid or having conditioning chemicals in the system shall be separated from the potable water by double wall construction. There shall be an air gap open to the atmosphere between the two walls. Where the boiler (heating chamber) operates in excess of 65 p.s.i., the requirements of subsection (a)(5) of this Section shall also apply.
5) No heat exchanger will be permitted on any boiler system operating in excess of 65 p.s.i., or high temperature hot water system operating in excess of 250°F, or any steam boiler operating with a pressure in excess of 50 p.s.i., unless:
A) the heat exchanger is double-walled; and
B) the heat exchanger has an air gap open to the atmosphere between the 2 walls; and
C) the heat exchanger has a pressure gradient monitor system with a "fail-safe to off" switch installed to isolate the heat exchanger from the potable cold or hot water system. If pressure on the potable water side reaches a pressure less than 20 p.s.i. above the pressure of the transfer fluid or steam and a pressure reducing valve is installed on the inlet to the heat exchanger with a setting 20 p.s.i. lower than the potable water pressure at the heat exchanger, an audible alarm shall be activated and the heat exchanger shall be automatically shut off until the alarm and heat exchanger can be reset manually.
6) Any boiler using toxic chemicals shall have a label with a minimum size of 5 inches X 5 inches attached to the boiler in a conspicuous place. The label shall read as follows:
Chemicals and additives used to treat the boiler feed water in this boiler are not approved for potable water. The steam or hot water produced by this boiler is not potable. If the steam or hot water produced by this boiler is used to heat water, the water will not be considered potable if the steam and potable water are mixed.
7) Indirect, External, Submerged Coils. Indirect, external, tankless or submerged coils used in heating water shall be equipped with a thermostatic mixing valve or valves when not connected to a storage tank. A pressure relief valve shall be installed on the cold water inlet of the tank. A properly sized temperature and pressure relief valve, based upon the energy input rating of the coils, shall be installed on the tempered line with the temperature sensing element immersed in the tempered water line as close as possible to the mixing valve.
8) Direct Fired Instantaneous Heaters. (Storage tank of more than 64 fluid ounces.) Direct fired instantaneous water heaters shall be equipped with a thermostatic mixing valve or valves which conform to ASSE 1017-1999. A pressure relief valve shall be installed on or adjacent to the heater. A properly sized temperature and pressure relief valve, based upon the energy input rating of the heater, shall be installed on the tempered line with the temperature sensing element immersed in the tempered water line as close as possible to the mixing valve.
9) Water Heaters Used for Space Heating. Any water heater to be used for space heating, in addition to hot water supply, must conform to ANSI Z21.10.1a-1991, shall be constructed for continuous use, and the piping for space heating shall be conducted to a proper terminal heating device.
A) A thermostatic mixing valve, conforming to ASSE 1017-1999, shall be installed on the hot water line to the plumbing fixtures. (The mixing valve shall be set to prevent temperatures exceeding 120°F from reaching the plumbing fixtures.)
B) A single check valve shall be installed in the cold water line supplying the water heater. (This will prevent hot water backing up from the heating unit to the plumbing fixtures.)
C) A properly sized and approved expansion tank shall be located on the outlet side of the check valve in the water heater's cold water supply with no shut-off valve between the heater and expansion tank.
D) Valves (manual, automatic) supplying hot water to the heat transfer unit for space heating shall have a minimum of a ⅛ inch orifice. (This will prohibit potable water from standing in the heat transfer unit when not in use.) This does not prohibit full shut off/isolation valves on either side of the pump within a heat transfer unit, as needed, to permit the servicing of the pump.
E) The water heater instructions shall have a statement specifying that piping and components connected to the water heater for the space heating application shall be suitable for use with potable water, and the water heater shall not exceed a developed length of more than 25 feet from the heating coil.
F) A statement specifying that toxic chemicals, such as those used for boiler treatment, shall not be introduced into the potable water used for space heating shall be included in the instructions. A label with the following words shall be firmly attached to any water heater used for space heating: "DO NOT INJECT TOXIC MATERIALS INTO THIS TANK."
G) A statement specifying that a water heater which will be used to supply potable water shall not be connected to any heating system or components previously used with a non-potable water heating appliance shall be included in the installation instructions.
H) Each water heater shall bear a statement on the rating plate as follows: "SUITABLE FOR POTABLE WATER HEATING AND SPACE HEATING."
10) Point-of-Use Instantaneous Water Heaters. Point-of-use instantaneous water heaters (high temperature, non-storage or storage of 64 fluid ounces or less, non-pressurized relative to atmosphere) shall meet the following requirements:
A) Units intended to deliver water temperatures exceeding 110°F, or with no mechanical or electrical temperature limiting device must have the faucet located at least 3 inches from the 110°F hot water or cold water faucet. All such faucet outlets shall have labels clearly and conspicuously indicating extremely hot water.
B) Units intended to deliver water temperatures 110°F or less shall have an internal burnout element or shall have a factory set thermostat that is not adjustable to higher than 110°F.
C) All pressurized point-of-use water heaters shall also have provisions as a part of the unit to provide temperature and pressure relief. Valves shall be set to relieve at 20°F above the intended water temperature and at 125 p.s.i. or at 15 p.s.i. below the pressure rating of the lowest rated part of the assembly, whichever is lower.
11) Steam Heat. All water heaters including storage heaters, instantaneous shell and tube heat exchangers, steam injection heaters and any other device using steam to heat water for potable use shall meet the following requirements:
A) All chemicals and additives used to treat the boiler feed water in a boiler supplying steam to heat potable water must be proper for use with potable water. Where such approved chemicals and additives are used with steam boilers generating at 15 p.s.i. or less, or are used with pressure reducing stations with pressure relief valves set at 15 p.s.i. or less downstream from the pressure reducing valves, single wall heat exchangers may be used.
B) Steam injection heaters must be supplied with steam from a generator or boiler which uses only United States Food and Drug Administration (FDA) approved additives or chemicals.
C) The following warning label with a minimum size of 5 inches X 5 inches shall be permanently attached to each steam injection heater:
"If the chemicals used to treat the feed water to provide steam for this steam injection water heater are not approved for potable water, the hot water from this heater shall not be considered potable. Therefore, each cross connection between the hot water and cold water connections to or from this heater must be provided with a device to prevent the backflow of hot water or steam condensate into the potable water supply."
D) The following warning label with a minimum size of 5 inches X 5 inches shall be permanently attached on the front of any boiler providing steam to direct injection steam hot water heaters:
"If the chemicals used to treat the boiler feed water in this boiler are not approved for potable water, the steam produced by this boiler cannot be considered potable. Therefore, if steam from this boiler is used to heat water, the water shall not be considered potable and any cross connections between the hot water produced and a potable water supply must be provided with a device to prevent the backflow of the non-potable hot water into the potable water supply."
b) Water Heaters – Food Service. Water heaters installed and utilized in food service establishments with dishwashing machines shall comply with National Sanitation Foundation (NSF) Standard Number 5.
c) With the exception of special water heaters used for space heating in addition to hot water supply, as provided in subsection (a)(9) of this Section, water that leaves the potable water system for heating, cooling, use in equipment or other similar uses shall not be returned to the potable water distribution system. When such water is discharged to the building drainage system it shall be discharged through a fixed air gap.
(Source: Amended at 28 Ill. Reg. 4215, effective February 18, 2004)