Performed annual furnace maintenance 7 yr split Rudd system attic. Cleaned burners and flame sensor. Variable speed motor ok. Found system in attic leaking air under unit. Recommend sealing unit. Also system has regular filter recommend switching to washable filter, so we can wash it when we come out. Also found evidence of rodents at hatch. Cleared platform so as not to track mess around house. Seal leak between furnace and coil with tape and sealant. And ordered washable filter to be sent to client. Chanse is returning one the 8th to install a new Koehler ada comfort height elongated toilet