I too had the FH error. By running the diagnostic test, I was able to eliminate the flowmeter because step C01 ran and water was flowing into the tub. After searching the internet I figured it was probably the pressure switch and/or it’s hose. I order the parts and started to replace them. The pressure hose is connect to the Airtrap. What I found was my airtrap was completely clogged. Since nothing was “flowing” to the pressure switch, it detected that there was no water entering the tank and generated the FH error. I removed the airtrap and clean it. I re-ran the diagnostic test and no FH error. I really don’t think the pressure switch was the problem, but it was not that expensive for the part so I figured I would use it anyway. So you may want to check the Airtrap.