Smoke and carbon monoxide alarm with hissing in basement

Fire control, Middleport service call (number withheld) North Hartland Street between Chase Road and Sleeper Street for the combination smoke CO alarm activation.

Caller does say they hear hissing sounds coming from the basement.

Incident is going to be on FD Tech One.

Repeating to Middleport service call (number withheld) North Hartland Street between Chase Road and Sleeper Street for the combination smoke and CO alarm activation.

The sounds of hissing coming from the basement.