Your RV water pump is humming away but nothing's coming out of the faucet. Or it runs and never shuts off. Before you replace the pump, work through this — most pump problems have a fixable cause that isn't the pump.
Your RV water pump is one of those things that's completely invisible until it stops working — and then it's the only thing you can think about. No water pressure. Or worse: the pump runs constantly without stopping, draining your batteries overnight while you sleep.
Before you order a replacement pump, work through this. Most pump problems have a fixable cause that doesn't require a new pump.
Symptom 1: Pump Runs But No Water Comes Out
This is almost always an air-in-the-lines or empty-tank problem — not a pump failure. The pump is doing its job; it just has nothing to push.
Check your fresh water tank level
Obvious, but frequently overlooked. Many RV tank gauges read inaccurately, especially when the tank is below 25%. If you're not sure, manually check or fill it before proceeding.
Check the pump inlet strainer
Most RV pumps have a small inline strainer on the inlet side. If it's clogged with debris, the pump can't draw water. It unscrews, rinses clean in 30 seconds, and goes back in.
Check for air leaks on the inlet side
A loose fitting or cracked line between the tank and pump inlet lets air in, breaking the pump's prime. Inspect every connection on the suction side of the pump and tighten or repair anything loose.
Check the pump inlet valve
Some RV setups have a shutoff valve between the fresh tank and the pump. Make sure it's fully open.
Symptom 2: Pump Runs Constantly (Won't Shut Off)
The pump has a pressure switch that tells it to stop when the system reaches the target pressure. If it's running continuously, the system isn't building pressure — which means there's a leak somewhere, or the pressure switch has failed.
- Walk through every faucet, toilet, and water connection in the rig — look and listen for drips
- Check under sinks and at the water heater connections
- Check the toilet fill valve — a stuck or failing valve leaks water continuously into the bowl
- Check the water heater pressure relief valve — if it's weeping, it may need replacement
- If no visible leak is found, the pressure switch on the pump may be faulty and need replacement
Running pump = running clock on your batteries
A 12V RV water pump draws 5–8 amps while running. If it runs continuously overnight because of a small leak or failed pressure switch, that's 60–96 amp-hours drained from your battery bank before you wake up. If you notice the pump cycling when no water is in use, shut it off at the pump switch or breaker before going to bed and investigate in the morning.
Symptom 3: Pump Runs But Pressure Is Low
- Check for partially blocked strainer (same as above)
- Check for a kinked or partially crushed water line between pump and faucet
- Check for a partially closed shutoff valve somewhere in the system
- Low-pressure can also mean the pump is at end of life and losing output — a pump that runs hot, makes grinding noises, or vibrates excessively is probably failing
Symptom 4: Pump Makes Noise But Won't Run
If you hear a click (relay energizing) but the pump motor doesn't turn, check your 12V supply to the pump. Use a multimeter to verify voltage at the pump terminals when the pump switch is on. Below 12V under load suggests a wire, connection, or fuse problem — not a pump failure. No voltage at all means trace back to the fuse, breaker, or switch.
Common Question
How long do RV water pumps last?
A quality 12V RV pump (Shurflo 2088 or equivalent) typically lasts 5–10 years with normal use. Heavy use, running dry frequently, or poor water quality (sediment) shortens that considerably. If your pump is older and starting to lose pressure or run rough, it's worth budgeting for a replacement soon rather than being caught without water at a campsite.
If you've worked through the checklist and still can't get your water system running right, give us a call. We diagnose and repair RV plumbing on-site throughout Redding and all of Northern California. Learn more about our RV plumbing repair service.
BossBros RV Team
Redding, CA