Arrived to find unit running intermittently, observed unit running until it dropped out, giving 45 code, low pressure switch open while inducer is @ high speed. Problem seems to be isolated to low pressure switch, I verified unit wasn’t plugged up or not draining or that we had any vent problems. When unit fires up one in awhile it’ll just all the sudden drop out (45). I also verified the inducer was drawing 1.5†wc and switches are .40â€-.30†diagnosis is failing low pressure switch ordering new