SUD F35 Error After reading numerous forums it appeared that there was no alternative but to replace the pressure switch. I did what one forum suggested to make sure the pressure hose was clear. I tried to order a part through Amazon for $97.00 but the manufacturer would not allow sales into Canada. Great! All the part suppliers in Canada want $150.00 to $180.00 and there was a three week lead time. Great again, and the laundry is piling up. How complicated can this pressure switch be? If excessive suds is causing the problem then it must be clogged or dirty. Let try cleaning the thing. I had a can of electrical contact cleaner much like brake cleaner and gave the contacts a shot or two. Why not clean the switch mechanism...nothing to loose, right. I filled the switch cavity with the cleaner, gave it a good shake and the drained and allowed it to dry. Bingo! We're on our sixth load and laundry pile is gone. Hope this helps.