Shurflo 4901-4202 pump
My 4gpm, 4-diaphragm, pump
cycles for no apparent reason. The original pressure switch was bad based on the backflow I got when pressurized. The new switch changed the frequency and duration of the runs, but it still cycles for no apparent reason:
We have a large accumulator, and a substantial amount of water
has to pass before it drops pressure enough to kick the pressure switch. So, if there were a leak, it would be substantial in the amount of water
it would display on looking...
But we find no such leak (or any at all, for that matter).
So, I call Shurflo. The rep tells me that smacks of firmware; one of the reasons they discontinued this pump 4-5 years ago is that the firmware started to fail.
Firmware??? I just replaced the switch. No, it's in the BASE (the part you screw to the bulkhead or shelf) - despite there being no electrical
connection between the base and the pump body, on which body (he called it the bottom; I guess he expects a horizontal mount) it mounts, sez he.
And the firmware 'remembers' what it's been doing, and continues to do that; in my case, due to the leakdown, is that it cycles often - if it's a firmware problem - that it's "remembering".
The solution, rep sez, if there is any hope, is to physically disconnect the wires from power; a breaker isn't sufficient - it still has a micro-amp draw if there is a physical connection (WTF??). Otherwise, even if we were to send the pump to them, there's nothing he could do about it (base obsolete? I didn't ask the question, as he was addressing the firmware issue). The parts
PDF shows, but does not identify as a part number, the base. Seems to me that this would be a replacement item if there's something which controls the pump.
search for firmware and Shurflo pumps came up dry, so if there is such a thing, it's well hidden.
Has anyone else heard of "firmware" in a Shurflo pump? Or had our issue and solved