A short cycling a water pump means that the pump shuts on and off too quickly. If you’re having this problem, here are the four most common reasons for short cycling pumps here.
Insufficient Air Charge In The Water Tank
Loss of air charge inside your water tank is the most common cause of short cycling. It is an especially common problem for older models and non-bladder type (also called captive air tanks) water pressure tanks. Newer bladder type tanks can also develop this problem when the bladder is damaged.
Here are three fixes you may need to try (steps 1 and 2 are for non-bladder style tanks)
1. Repair the tank air volume control.
2. Drain the water tank and let air re-enter the tank.
3. Drain the water from the tank and use the air inlet valve to recharge air back into your tank. The air charge should be 2 psi lower than you pump cut-on pressure.
Defective Water Pump Pressure Control Switch
Water pressure control switches can fail. Contacts can burn out, and the opening of the switch that detects pressure in the system can get clogged with debris and sediment. This most often appears as a failure of the switch to turn the pump on or off at all, as opposed to just short cycling. The switch may be damaged or need adjustment. This can cause short water-pump cycling. Depending on the severity, you could fix it by either cleaning the switch contacts or replacing the switch entirely.
Blocked Water Supply Piping
Clogged piping or water filters can cause short water-pump cycling. The blockage will cause water pressure to rise quickly when the pump switches on. It’s common for people to replace their pump controls only to find that a clogged filter was the real problem. Be sure to check the water supply piping if you have a filter installed on your system.
If the filter has a bypass valve, open it to see if it stops short cycling. If there’s no bypass valve for the water filter, turn the pump, and the valves around the water filter, off. Then remove your water filter cartridge, clean and reassemble it. If the short cycling stops you’ve likely had a clogged filter. Replace the cartridge.
Irrigation Zones Are Too Small
When a pump is used for irrigation and the flow rate is too low, the pump can reach its cut-off pressure very quickly. This is happens most often with small or low flow rate zones such as drip irrigation. This problem can usually be corrected by running the small low flow rate zones simultaneously with another zone. The higher flow rate allows the pump to come on and stay on until the irrigation cycle is completed.
If your water pump is on the fritz, contact W.P. Law, Inc.