Clearances.
Municipal Code of Chicago § 18-28-803.10.6
in effect18-28-803.10.6 Clearances.
Connectors shall have a minimum clearance to combustibles in accordance with Table 18-28-803.10.6. The clearances specified in Table 18-28-803.10.6 apply, except where the listing and labeling of an appliance specifies a different clearances, in which case the labeled clearance shall apply. The clearance to combustibles for connectors shall be reduced only in accordance with Section 18-28-308.
Table 18-28-803.10.6
Connector Clearances to Combustibles
Type of Appliance | Minimum Clearance (Inches)
Type of Appliance | Minimum Clearance (Inches)
Domestic-type appliances
Chimney and vent connectors |
Electric and oil incinerators | 18
Oil and solid fuel appliances | 18
Oil appliances labeled for venting with Type L vents | 9
Commercial, industrial-type appliances
Low-heat appliances
Chimney connectors |
Oil and solid fuel boilers, furnaces and water heaters | 18
Oil unit heaters | 18
Other low-heat industrial appliances | 18
Medium-heat appliances
Chimney connectors |
All gas, oil and solid fuel appliances | 36
High-heat appliances
Masonry or metal connectors |
All gas, oil and solid fuel appliances | (As determined by the Building Commissioner)
For SI: 1 inch = 25.4 mm.
(Amend Coun. J. 9-14-21, p. 35949, Art. VIII, § 2)
Source: City of Chicago, Municipal Code of Chicago (American Legal Publishing, codelibrary.amlegal.com)URL: https://codelibrary.amlegal.com/codes/chicago/latest/chicago_il/0-0-0-2687895Fetched: 10/24/2026