Appliances, Equipment, and Installation Clearances
This domain tests appliance and equipment installation: listing, manufacturer instructions, combustible clearances, service access, floors, attics and roofs, condensate disposal, safety devices, and protection from damage.
Core rules
- Appliances must be listed for the application and installed per the listing and manufacturer instructions. A code clearance does not override a stricter listing clearance.
- Clearance to combustibles is measured from the appliance, vent connector, and piping to the protected or unprotected surface. Reduced clearances require approved protection methods or listed assemblies.
- Service access must allow inspection, maintenance, and replacement. Do not place equipment where doors, access panels, or electrical disconnects are blocked.
- Floor construction, elevated platforms, attic access, roof curbs, and seismic anchorage must support the equipment and its operating weight. Condensate must drain to an approved location without trapping or freezing.
- Safety devices such as limit controls, flame safeguards, relief valves, and door interlocks must remain functional and not be bypassed.
Worked example
A furnace is listed for zero clearance to combustibles on its sides but requires 24 in of front service clearance. The installer leaves 12 in in front because the closet door opens outward. The installation fails: zero side clearance does not waive the front service access, and the door swing may further obstruct maintenance. The plan must show the listed clearances and actual access.
Traps
Confusing clearance to combustibles with service clearance; assuming drywall always permits reduced clearance; ignoring door swing and disconnect access; installing condensing equipment where the condensate cannot drain; and blocking or bypassing safety devices.