2018 York furnace has a fault history for pressure switch. Found drain plugged up with mud from a mud dobbler. Cleared out mud from drain, added dish soap, dumped water from draft motor, and reassembled.unit is working now but Informed customer of possibility of water getting into pressure switch. Parts are covered under warranty just not labor charge to install them. Offered to order new switches under warranty but customer declined since unit is working. Did heating maintenance today.