Looking for ideas. I have a two day old Ruud U962VA07 throwing A047F error code: IDM 5 min lock out. It was recommended to replace pressure switches, which was done. It threw the code adain with in an hour. IDM is creatating 1.5" w.c. draft almost twice the rating on the switches. What else can throw that code? Bad IDM? (Amp draw, voltage and capacitor are all ok) Bad board? Any ideas, however improbable are welcomed. Thank you
I believe the 5 min soft lockout is caused because the low pressure switch does not close.
I would take a look at the venting or drainage system and make sure it's sized and installed properly.
Likely if it's running for an hour before tripping it's an accumulation of water somewhere that's causing the pressure switch to trip. Maybe the venting is not sloped properly or you need an air vent in the drain line. Check that the vent termination is correct and not reversed.
Pictures of the entire installation would help.