A borehole pump works out of sight, dozens of meters underground. That is why failures feel sudden — but they almost never are. Weeks before a pump stops, its current draw, flow rate, and water level start telling the story. A simple maintenance routine is how you read that story early, when the fix is still cheap.
This guide gives you a practical schedule for submersible borehole pumps (our QJ/QJT type and similar makes), plus the records that matter and the mistakes that shorten pump life.
Why Maintenance Pays for Itself
Pulling a pump for an unplanned failure costs far more than the repair itself: the crane or tripod crew, the transport, the downtime — and on a farm or village supply, the water you do not have while the pump is out. Planned checks cost minutes. An emergency pull-up costs days.
The deeper and more remote the well, the more this matters. If your pump serves a farm, a community supply, or a mining camp, maintenance is not a chore — it is insurance.
The Maintenance Schedule
Most of the schedule is done at the surface, without pulling the pump:
| Interval | What to do | What it catches |
|---|---|---|
| Every visit / daily | Listen at the wellhead for unusual noise; glance at the control panel; look at the discharged water — flow, color, sand | Cavitation, bearing wear, sand ingress, dry running |
| Weekly | Record operating current (A) and voltage (V) at the panel | Blockage, wear, phase problems, supply issues |
| Monthly | Measure flow (meter or timed bucket); note the dynamic water level if you can measure it | Wear, falling aquifer level, wrong operating point |
| Quarterly | Inspect wellhead cable and joints; confirm the check valve holds (no back-spin after stop); clean panel vents and filters | Cable damage, water hammer, overheating electronics |
| Annually / by running hours | Megger test (insulation resistance) by a qualified electrician; compare the full set of readings against the commissioning baseline; decide whether a pull-up inspection is due | Motor insulation aging, seal failure before it happens |
The Five Numbers Worth Writing Down
You do not need instruments everywhere — you need a notebook (or a spreadsheet) with five numbers, taken the same way each time:
- Operating current (A) — the single most informative reading on a submersible pump
- Voltage (V) at the panel while running
- Flow rate (m³/h) — metered or timed into a tank
- Dynamic water level (m) — the level while pumping, not at rest
- Insulation resistance (MΩ) — at commissioning, then annually
The trend matters more than the absolute value. Current creeping up while flow drops means wear or blockage. A falling dynamic level means the aquifer is declining — lower the pump or reduce duty; do not just let it run closer to dry. Keep the commissioning-day readings as your baseline. Every Ganquan pump is tested on our factory test stand before dispatch, and the test record that ships with the pump is a good starting baseline for your own log.
Five Mistakes That Shorten Pump Life
- Waiting for a trip. A tripped breaker is the end of the story, not the beginning. Read the trends first.
- Ignoring sand. Sand in the discharge water wears impellers and bearings fast. If you see sand, act — see our troubleshooting guide for the checks.
- Bypassing dry-run protection. Dry running can destroy a pump in minutes. If your panel has dry-run detection, never bridge it out “to keep the water flowing.” If it does not, read how dry-run protection works.
- Poor underground cable splices. A badly waterproofed joint underground is a slow-motion motor failure. Use proper splice kits and test insulation after any joint work.
- Choking the pump for months. Submersible motors are cooled by the water flowing past them. Running far below the rated flow point for long periods can overheat the motor — if you must throttle, confirm the minimum flow for your model with the manufacturer.
Signs It Is Time to Pull the Pump
- Current rising and flow falling together over weeks
- Sand content in the water increasing
- Insulation resistance falling compared with the baseline (your electrician judges the threshold)
- Repeated protection trips you cannot explain — work through the symptom guide first
Pulling early, on your schedule, is always cheaper than pulling after a burnout.
Water Quality Changes the Interval
The schedule above assumes clean, cool well water. Sandy water, corrosive water (low pH or high chloride), or high water temperature all shorten every interval — and they also change the right material choice for the pump itself. If your water is aggressive, tell us when you enquire: material and seal options are confirmed per order with the factory.
FAQ
How often does a borehole pump need maintenance?
Surface checks run daily to quarterly as in the schedule above. A full pull-up inspection depends on running hours and water quality — there is no universal calendar number. Your trend records tell you when it is time.
Can I maintain a borehole pump without pulling it out?
Yes — most of the schedule (current, voltage, flow, water level, panel and wellhead checks) is done at the surface. Pulling is only for inspection, repair, or replacement.
How long does a borehole pump last?
It varies widely with water quality, duty cycle, and sizing. Two things extend life more than anything else: sizing the pump correctly for the well (see well depth vs pump head), and working dry-run protection. Sand and heat shorten life; good records catch both early.
What is the single most important check?
Operating current, recorded weekly. It is one number, it takes a minute, and it reflects almost everything happening downhole.
Need a Hand?
Choosing a pump for a new well? Start with the borehole pump range or try the online pump selector. For maintenance questions on a specific installation, contact our team or message us on WhatsApp — tell us your well depth, flow requirement, and what the pump is doing, and we will help you work it out.