A leak at an equipment collar can be a duct seating problem, a sealing problem, a support problem, or a manufacturer/cabinet connection problem. Identify which seam is leaking before smearing sealant over it.
Do not smear sealant over a loose or stressed equipment connection.
Check
First identify whether the leak is at the collar-to-duct connection or at the collar-to-equipment cabinet connection. Those are different fixes.
For a collar-to-duct leak: check whether the duct is fully seated, mechanically fastened per job standard, and sealed with the approved method. Re-seat before sealing if it is not fully engaged.
For a collar-to-cabinet leak: hold before covering it with sealant. The collar may need to be reattached, re-gasketed, or adjusted per manufacturer/submittal direction.
Check whether duct weight is pulling the collar off the cabinet face. If so, correct support first, then seal.
Photograph and describe the leak location specifically, such as 'collar-to-duct seam, north side' instead of just 'leaking at unit.'
Steps
First identify whether the leak is at the collar-to-duct connection or at the collar-to-equipment cabinet connection. Those are different fixes.
For a collar-to-duct leak: check whether the duct is fully seated, mechanically fastened per job standard, and sealed with the approved method. Re-seat before sealing if it is not fully engaged.
For a collar-to-cabinet leak: hold before covering it with sealant. The collar may need to be reattached, re-gasketed, or adjusted per manufacturer/submittal direction.
Check whether duct weight is pulling the collar off the cabinet face. If so, correct support first, then seal.
Photograph and describe the leak location specifically, such as 'collar-to-duct seam, north side' instead of just 'leaking at unit.'
Say this to your foreman
I have a leak at the equipment collar on [unit tag] at [location]. It looks like it is at the [collar-to-duct / collar-to-cabinet] connection. Do you want me to re-seat and seal, add support first, or hold for direction?