Flojet water pump issues

[28Bunkhouse]

Greetings, I thought I would share an experience we had on summer vacation.We discovered our water pump running continuosly, but not very loud. When used water the pump would sound normal. I did an internet search on the pump and found many posts complaining of the same issue. A number of people claimed the pressure switches were faulty and either repaired or replaced their pumps. I promptly ordered a new pump on Amazon.ca (once I had internet access. Upon returning to camp I turned the pump back on, same issue. I started to do investigating work and discovered our 12vdc battery was almost dead, we had been running our generator morning and evening and assumed the battery was good. With the battery fully charged the pump works properly and I now have a sprare.The new pump documentation covers the fact that low voltage can cause what we were experiencing.
Just thought I would share and sage someone else the expense.
Bunkhouse

[jsmith948]

Good info to have. Thanks for sharing. That's what is great about this forum.

[JRTJH]

The reason Flojet pumps have this problem is the low voltage. In normal operation, when the water pressure drops, the pressure switch closes, the pump starts running and as water pressure increases, the pressure switch opens and the pump shuts off.

When battery voltage is low, the water pressure drops, the pressure switch closes and the pump starts running (slower) and water pressure can't build up high enough to open the pressure switch. The pump continues to run, but can't build higher water pressure, so it "cavitates" and the sound level drops. If allowed to continue to run in that condition, eventually the motor will overheat and "self destruct" (unless the battery discharges first). If a faucet is opened, the pump noise level increases as water is forced through the pump (at a lower pressure) until the faucet is closed, then the "quiet pump" sound returns. The pump will continue to run indefinitely because it can't build water pressure high enough to open the pressure switch. It's usually not a "bad pump" or a "faulty pressure switch" but rather low voltage. Once the battery is recharged or shore power is connected, normal operation returns.

Many times, owners will notice the "quiet pump" and turn off the water pump switch. That will prevent overheating the pump and protect it from damage.