Customer stated: they have a carbon monoxide issue. Tech notes: called out today to look at an issue with a carbon monoxide leak. While on site home owner stated the fire department came out and detected some carbon monoxide between the floors. Fire department stated it is because the furnace does not have a filter. THIS ISSUE IS REQUIRED FOR AN HVAC TECHNICIAN TO COME OUT AND REPAIR THE ISSUE WITH THE FURNACE DUE YO IT BEING AN EXHAUST ISSUE WITH THE FURNACE. Resolution: no plumbing issue! HVAC tech is needed on site. Job status complete. Job notes no clean out. Hose bibs are off. Estimates; none needed.