Then the technician will go through and thoroughly clean and disinfect with environmentally friendly Then the technician will go through and thoroughly clean and disinfect with environmentally friendly products. If there is a crack or hole somewhere, rodents could get in. A leak could allow water to get into the system causing there to be a musty or moldy scent. One way to find out is by checking the thermostat....15Jun2022Box-Type Units Manufacturers