Is your water pump making an annoying clicking sound? This common issue, known as water pump cycling, can be more than just irritating; it can also damage your pump if left unaddressed. Understanding why this happens is the first step to fixing it. Here’s what you need to know:
What is Water Pump Cycling?
A water pump that is constantly switching on and off is “cycling”. This happens when the pump is operated by internal pressure switches. These switches respond to the water pressure in the outlet pipe. There are two switches:
- Low-pressure switch: This switch turns the pump on when the water pressure drops.
- High-pressure switch: This switch turns the pump off when the water pressure gets too high.
When you use water, the low-pressure switch activates the pump. Once the tap is closed and the pressure builds up, the high-pressure switch turns the pump off.
Common Causes of Water Pump Cycling
Several factors can cause your pump to cycle on and off:
- Incorrect Pressure Switch Settings: If the low and high pressure switch settings are too close, even small changes in water pressure will cause the pump to switch on and off. Typically, the low-pressure switch is set around 20 psi (1.4 Kg/sqcm), and the high-pressure switch around 40 psi, but these can be adjusted.
- Oversized Water Pump: A large pump supplying a small shower or tap can cause cycling. The pump might push water faster than the shower head can release it, leading to a rapid build-up of pressure and frequent on/off cycles. This can also result in pulsing water from the shower. If you have multiple bathrooms, consider using multiple smaller pumps instead of one large one.
- Small Leaks: A small leak in your pressurized water system can cause the water pressure to drop quickly, triggering the pump to switch on. The pump will then build pressure and switch off, and the cycle will repeat if the leak persists. A slow cycling pump indicates a small leak, while fast cycling points to a larger leak.
- Faulty Pressure Tank: Pressure tanks (also known as accumulators) are designed to mitigate the cycling issue by using compressed air to maintain a steady water pressure. If the air in the pressure tank escapes, or the rubber bladder inside bursts, it will not function correctly, and the pump will cycle.
- Water Tank Issues: Older water systems with ball valves in the water tank might also contribute to the issue. When the water level drops, even a small amount, the valve opens, and the pump switches on, but it is unlikely to be the primary cause of cycling.
How to Troubleshoot Your Cycling Pump
Here’s a step-by-step guide to diagnose the problem:
- Check for Leaks: Make sure all water outlets are off. If the pump is still cycling, there’s likely a leak. Check for dripping taps, running toilets, and any leaks, especially a dripping jet washer in the toilet or the pressure relief valve on your water heater.
- Inspect Your Property: Look for evidence of leaks in your garden, such as lush patches of foliage or wet areas. Check pipes in walls, which can leak due to poorly glued joints.
- Isolate the Leak: Try turning off stop cocks in the piping system to determine the leaking area.
- Examine Your Pump: If you can’t find any leaks, it’s important to check your pump settings. You can also check the pressure tank (if applicable) for a loss of air or a damaged bladder.
- Call a Professional: If the problem persists, contact a qualified plumber. They can check the pump’s pressure switch settings, the pressure tank, and diagnose leaks in your system.
Key Takeaways
- Cycling is not normal: Constant on/off cycles indicate an issue.
- Small leaks are common culprits: Check your taps, toilets, and pipes thoroughly.
- Pressure settings matter: Ensure the low and high-pressure switch settings are properly adjusted.
- Pressure tanks require maintenance: Check the air pressure and bladder regularly.
- Don’t ignore the problem: It can damage your pump.
By following these steps, you can effectively troubleshoot your cycling water pump and ensure a reliable water supply for your home.
