Furnace Maintenance PCSA 2022 Heating Check Up Prepaid. Gas furnace is checking out good at this time, filter is changed and drains are clear. Had a mild co reading In the house, however, co detectors are all up to date and tested. Found the dryer vent to gas dryer was un-done and customer is aware. They are going to re-attach it and monitor. As will we continue to monitor. They also have a gas fireplace, however, it is not in use at this time. Gas furnace co readings are normal.