Customer had us out due to no heat. Found system would run for 5-10 minutes and shut off. Did this 5 times till the lockout. Code says pressure switch open. Found water coming from flue vent. Inspected flue vent from outside home and it appear to be bent up and leaning. Removed flue vent in attic and system ran for 20 plus minutes with no issues. We recommended having roofer out to correct the flue vent and cap. Also noticed very dirty filter and ducts. Customer has no TE standard wet switch. Highly recommended we install a wet switch, uv protection, and clean duct work.