Ch. 12 Hydronics — 2025 California Mechanical Code
California Mechanical Code (Title 24, Part 4) · 2025 edition · updated 2026-10-19 · California
CBSC: official editions, supplements and errata
Italicized text is a California amendment to the model code, as printed in the official publication.
Cite as: 2025 California Mechanical Code (Title 24, Part 4) Chapter 12 · Effective January 1, 2026 · Official source: Building Standards Commission
(Matrix Adoption Tables are non-regulatory, intended only as an aid to the code user. See Chapter 1 for state agency authority and building applications.)
| Adopting Agency | BSC | BSC-CG | SFM | HCD 1 | HCD 2 | HCD 1-AC | DSA AC | DSA SS | DSA SS/CC | OSHPD 1 | OSHPD 1R | OSHPD 2 | OSHPD 3 | OSHPD 4 | OSHPD 5 | OSHPD 6 | BSCC | DPH | AGR | DWR | CEC | CA | SL | SLC |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Adopt Entire Chapter | X | X | X | X | ||||||||||||||||||||
| Adopt Entire Chapter as amended (amended sections listed below) | X | X | X | X | X | X | X | |||||||||||||||||
| Adopt only those sections that are listed below | X | |||||||||||||||||||||||
| Chapter/ |
||||||||||||||||||||||||
| 1205.2, Note | X | X | ||||||||||||||||||||||
| 1210.2 | X | X | X | X | X | |||||||||||||||||||
| 1211.7, Note | X | X | ||||||||||||||||||||||
| 1217.8.2.1 | X | |||||||||||||||||||||||
| 1217.10.1 | X | |||||||||||||||||||||||
| 1220.4.7.1 | X |
This state agency does not adopt sections identified with the following symbol: † The Office of the State Fire Marshal’s adoption of this chapter or individual sections is applicable to structures regulated by other state agencies pursuant to Section 1.11.0.
CHAPTER 12
HYDRONICS
| TABLE 1201.10 PERCENT GLYCOL MIXTURES | ||
|---|---|---|
FREEZING POINT, °F |
FREEZING POINT, °F |
FREEZING POINT, °F |
(% BY VOLUME) |
ETHYLENE GLYCOL* | PROPYLENE GLYCOL |
20 |
16 | 18 |
30 |
3 | 8 |
40 |
-12 | -7 |
50 |
-35 | -28 |
For SI units: °C = (°F-32)/1.8 Note:
- Ethylene glycol shall not be used in one- and two-unit residential systems. In existing systems, where ethylene glycol is used, there shall be no direct or permanent potable water connections. Where a temporary potable water connection is required, a backflow preventer shall be installed.
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1201.0 General.¶
1202.0 Protection of Potable Water Supply.¶
1203.0 Capacity of Heat Source.¶
1204.0 Identification of Potable and Nonpotable Water Systems.¶
Water Systems.
1205.0 Installation, Testing, and Inspection.¶
1206.0 Pressure and Safety Devices.¶
1207.0 Heating Appliances and Equipment.¶
1208.0 Circulators and Pumps.¶
1209.0 Expansion Tanks.¶
1210.0 Materials.¶
1211.0 Joints and Connections.¶
1212.0 Valves.¶
1213.0 System Controls.¶
1214.0 Pressure and Flow Controls.¶
1215.0 Hydronic Space Heating.¶
1216.0 Steam Systems.¶
1217.0 Radiant Heating and Cooling.¶
1218.0 Heat Exchangers.¶
1219.0 Indirect-Fired Domestic Hot-Water Storage Tanks.¶
Tanks.
1220.0 Snow and Ice Melt Systems.¶
1221.0 Piping Installation.¶
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