Bore Pump Repairs: What Is Worth Fixing and What Is Not
Once you have established that the pump is the problem rather than the bore, the next question is whether to repair it or replace it. On a commercial bore that decision is rarely about the fault itself. It is about what it costs to get the pump out of the ground, how much life is left in the rest of the unit, and whether the pump was ever right for the duty in the first place.
Here is how that decision usually breaks down.
What actually fails, and what can be fixed
Most bore pump faults fall into one of five categories, and they differ enormously in how repairable they are.
Control gear. Pressure switches, contactors, overloads and variable speed drives fail more often than the pump itself, and they are the cheapest thing on the list to put right. A pump that will not start, trips repeatedly, or short cycles frequently has nothing wrong below ground at all. This is always worth checking before anyone books a crane.
Cable and splices. Insulation breakdown in the drop cable or a failed splice will take a pump offline and can be mistaken for motor failure. An insulation resistance test distinguishes the two in minutes. Cable repair is straightforward once the pump is out.
Bearings and seals. Routine wear items. On a unit that is otherwise sound these are a standard rebuild and almost always worth doing.
Impellers and diffusers. Abrasive wear from sand and silt gradually erodes the hydraulic components, which shows up as falling output at unchanged power draw. Replaceable on most commercial pumps, though on badly worn units the cost climbs quickly.
Motor windings. Winding failure or insulation breakdown can often be rewound, but this is where the economics turn. On smaller units a rewind can approach the cost of a new motor. On larger high-capacity units it is usually worthwhile, provided the rest of the pump is sound.
The pull is the fixed cost
This is the part that catches people out. On a commercial bore, extracting the pump is most of the job. You need the plant to lift it, the rising main disconnected and drawn up in sections, and safe access for a truck or crane at the bore head. That cost is incurred whether you then replace a $200 pressure switch or the entire assembly.
Two things follow from that.
First, diagnose everything above ground before committing to a pull. Control gear, cabling and electrical supply account for a meaningful share of faults and cost a fraction to rectify.
Second, once the pump is out, the marginal cost of additional work is small. If the unit is coming up anyway, replacing wear items while it is on the surface is nearly always cheaper than pulling it again in eighteen months. Operators who repair only the failed component and put it straight back down often end up paying for two pulls inside two years.
Where the line sits between repair and replace
There is no universal threshold, but four factors decide it in practice.
Age against design life. A pump in the first half of its service life with a single failed component is usually worth repairing. One that has already run its expected duty cycle is being kept alive rather than fixed.
Efficiency. A worn pump costs money every hour it operates. If output has dropped while power draw has held steady, you are paying full running costs for reduced delivery, and that gap compounds on a unit running long hours through an irrigation season.
Whether the duty point still matches. Site demand changes. Areas get expanded, storage gets added, water levels drop. If the pump no longer suits what the site now needs, repairing it reinstates the original mismatch at your expense.
Parts availability. Obsolete units can be repairable in principle and impractical in reality once lead times on components run to weeks.
As a working rule, when a repair quote approaches half the cost of replacement on a unit past the midpoint of its life, replacement is usually the better commercial decision, because you reset the clock and recover the efficiency at the same time.
What a repair will not fix
Three situations where a rebuilt pump will fail again.
The bore is the actual problem. If yield has declined because the screen is fouled or the casing has degraded, a perfectly good pump will keep struggling and keep wearing. Establishing whether the fault sits with the bore or the pump before authorising work is the single most valuable step in the process.
The pump was wrong for the duty. Cavitation damage, persistent overheating and repeat seal failure are often symptoms of a selection error rather than a component fault. Repairing it puts the same problem back down the hole.
Abrasive damage without addressing the source. If sand is reaching the impellers, replacing them without dealing with the screen or the setting depth simply restarts the wear cycle.
Downtime is usually the real cost
For most commercial operations the repair bill is smaller than the consequence of being offline. A vineyard cannot pause an irrigation cycle in February. A mine site cannot suspend dust suppression. A council reserve loses turf.
Two things reduce that exposure. Holding critical spares on site, particularly control components and seals, turns a multi day wait into a same day fix. And a standby pump configured as duty or standby means a failure becomes a scheduled repair rather than an emergency, which is almost always cheaper.
What to have ready before you call
You will get a faster and more accurate answer if you can supply:
- The pump make, model and rated duty, along with the installation date if known
- Current flow and pressure against what the system delivered when commissioned
- Power draw, and whether it has changed alongside the flow
- Standing water level and drawdown, if recent figures exist
- Any fault codes from the controller or drive
- Access details at the bore head, including clearance for a truck or crane
That information usually tells us whether the problem is above ground, whether a pull is justified, and whether you are looking at a repair or a replacement, before anyone arrives on site.
Wallace Irrigation has worked on commercial and mining bore systems across NSW for more than 25 years, covering supply, installation, testing and ongoing maintenance. If you have a pump that has stopped performing, get in touch and we will work out what it needs.