When a bore pump begins losing pressure, most Australians assume the pump is failing and rush to replace it. The truth is pressure loss rarely comes from pump failure. It almost always comes from incorrect sizing, low bore yield, seasonal water level drops, pipe restrictions, or system design issues that can be fixed without replacing the entire pump.
This guide breaks down the real reasons bore pumps lose pressure in Australian conditions and shows you how to identify the cause quickly. If you need to choose the right pump after diagnosing the problem, you can explore options at Busselton Pumpshop or ask for help through the Contact us page.
Why Pressure Loss Happens in Bore Pump Systems
A bore pump must overcome depth, friction, elevation, and outlet pressure. When any of these factors change or are miscalculated, pressure drops. Pressure loss is often a symptom of something else, not the problem itself. Typical symptoms include:- Taps running weak
- Sprinklers failing to reach full spray
- Pump cycling on and off
- Slow water delivery
- Pressure tank not reaching its cut off point
- Water pulsing
- Pump taking longer to prime
1. Standing Water Level Has Dropped
This is the most common reason for pressure loss in Australia. During summer or heavy pumping periods, the water level inside the bore drops. A pump sized for a water level of 15 metres may struggle when the level drops to 22 metres. When water level drops:- The pump must push water further
- Pressure output decreases
- Flow rate reduces
- Pump works harder and heats up
How to check it:
Lower a weighted tape or probe into the bore when the pump is off and measure the current water level.Fix:
- Lower the pump deeper into the bore
- Reduce flow rate
- Use a storage tank system
- Upgrade to a pump suitable for deeper lift
2. Bore Pump Is Undersized
If the pump was chosen without measuring bore depth, water level, or total dynamic head, it may simply be too small for the job. Symptoms include:- Sprinklers that never reach full rotation
- Weak pressure at taps
- Water pressure drops when multiple outlets run
- Pump stays on constantly and never reaches cut off
Fix:
- Upgrade to a correctly sized pump
- Reduce the number of outlets used at once
- Increase pipe size to reduce friction
- Reduce elevation load
3. Pump Is Oversized and Cycling
An oversized pump is just as problematic as an undersized one. If the pump produces too much pressure, it will hit the pressure switch quickly and shut off. Then it restarts almost immediately. This rapid cycling causes inconsistent pressure, weak irrigation performance, and motor wear.Symptoms:
- Pressure spikes and drops
- Loud clicking from the pressure switch
- Pump turns on and off rapidly
- Water comes out in pulses
Fix:
- Install a larger pressure tank
- Adjust the pressure switch
- Move to a smaller pump if needed
4. Friction Loss in the Pipeline
Many Australians underestimate how much pressure is lost due to friction, especially when using narrow pipes over long distances. Small pipe diameter increases friction significantly. Long horizontal runs also contribute.Symptoms:
- Good pressure near the pump
- Weak pressure at distant outlets
- Irrigation lines losing power halfway
Fix:
- Increase pipe diameter
- Reduce pipe length or elevation
- Remove unnecessary elbows and fittings
5. Leaks in the Pipeline
Even minor leaks can destroy pressure. Underground leaks can go undetected for months.Symptoms:
- Pump runs constantly
- Pressure never stabilises
- Wet patches along pipeline
- Air in the water line
Fix:
- Inspect visible pipework
- Walk the property and look for damp soil
- Pressure test the system
- Repair or replace damaged sections
6. Bore Yield Is Too Low
When your bore produces less water than the pump requires, pressure will drop. If the pump is drawing water faster than the bore can supply it, the water level inside the bore falls rapidly.Symptoms:
- Water turns cloudy or sandy
- Water flow weakens after a few minutes
- Pump surging
- Pump shutting off due to overheating
Fix:
- Reduce pump flow rate
- Install a smaller pump
- Switch to a tank storage system
- Allow longer recovery time between pump cycles
7. Pump Wear and Tear
While pump failure is not the most common reason for pressure loss, it does happen. Worn impellers or a weakened motor reduce pressure output significantly.Symptoms:
- Pump louder than usual
- Gradual decline in pressure over months
- Vibration or irregular noise
- Pump overheating frequently
Fix:
- Inspect impellers
- Test motor performance
- Replace worn components
- Replace the pump if repair is uneconomical
8. Electrical Problems
A pump running on reduced voltage produces less pressure. Loose wiring, poor connections, or failing capacitors can reduce pump performance.Symptoms:
- Pump struggles to start
- Motor feels weak
- Pressure increases and decreases randomly
Fix:
- Check electrical connections
- Replace worn capacitors
- Test voltage at the pump controller
9. Blocked Filters or Screens
Many bores include intake screens or inline filters to prevent debris entering the system. Over time, these block and restrict flow.Symptoms:
- Slow pressure decline
- Dirty water
- Lower flow at all outlets
Fix:
- Clean intake screen
- Flush inline filters
- Inspect bore water for sediment issues
Common Questions Australians Ask
1. Why is my bore pump losing pressure suddenly?
Likely caused by water level drop, leaks, or blocked filters.2. Why does pressure drop when I use multiple taps?
Your pump is undersized or your pipework has excessive friction loss.3. Can a failing pressure switch cause low pressure?
Yes. Faulty switches cause cycling and unstable pressure.4. How often should I check my bore pump system?
Every 6 to 12 months, especially before summer.5. When should I replace the pump?
If impellers are heavily worn or the motor is failing, replacement may be more cost effective. For More Info:- Busselton Pumpshop
- Contact us