RV Water Pump: Symptom, First Checks, and Stop
Start with the symptom
Pick the row that matches what your Shurflo 4008 RV pump is doing, run the first checks, and stop where the table says to stop.
Pump will not start / blows circuit
Pump will not start / blows circuit
- First checks: Electrical connections, 10 amp circuit, fuse or breaker, main switch, ground, open or grounded circuit, wire gauge and size, voltage at the pump, bypass switch test, thermal breaker, seized pump assembly.
- Stop: If the motor is hot, stop and let the thermal breaker reset. If the pump is seized, stop.
If the motor is hot, stop and let the thermal breaker reset.
Motor runs, will not prime / sputters
Motor runs, will not prime / sputters
- First checks: Strainer clog, water in tank, air in hot water heater, vacuum leak, kinked or restricted plumbing, voltage under load, debris or swollen valves, housing cracks and drive screws
- Stop: If the housing is cracked or water is frozen, stop.
If the housing is cracked or water is frozen, stop.
Pump will not shut off / runs with faucet closed
Pump will not shut off / runs with faucet closed
- First checks: Output leaks, air trapped, voltage, loose drive/head screws, debris or swollen valves, pressure switch
- Stop: Fix leaks before adjusting the pressure switch. Do not raise the switch setting to hide a leak.
Rapid cycling
Rapid cycling
- First checks: Restrictive plumbing or faucets, filter on a separate feed, low shut-off pressure
- Stop: Stop if plumbing is restricted; do not raise pressure blindly.
Scope check
If your pump is not a Shurflo 4008, stop and use its own manual.
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