RDspaguy
In The Industry
Still the same issue. By putting it in economy you are changing when it allows it to heat. No call for heat, no flo error. As soon as you turn on the pump it initiates a call for heat. Either your flow switch is not closing, is not functioning, has a loose or corroded connection, or the circuit board is bad. Most likely it's just a bad switch, but check for a connection issue first, since that is free.