If your well pump clicks on and off every few seconds whenever a tap runs, it is short-cycling, and in homes around Kettleby, Schomberg and Nobleton the usual cause is a pressure tank that has lost its air charge or become waterlogged. A worn or mis-set pressure switch, a clogged switch port or a hidden leak can do it too. It is worth dealing with early, because every start wears the pump, and the pump is the part you least want to replace.
How a well system works in a King Township house
Most homes in and around Kettleby, rural Schomberg and parts of Nobleton rely on a private well rather than municipal water. In Nobleton the answer can change from one road to the next, so if you are not sure, check whether you get a water bill from the Township of King.
On a well, three parts do most of the work:
- The pump, usually down in a drilled well, lifts water to the house.
- The pressure tank holds a cushion of compressed air, separated from the water by a bladder or diaphragm. That air pushes water to your taps so the pump does not have to start every time you fill a glass.
- The pressure switch turns the pump on when pressure falls to its "cut-in" setting and off when it reaches "cut-out". A gauge near the tank shows where you are.
In a healthy system the pump runs for a while, fills the tank, then rests while you draw water from it. When the tank stops doing its share, the pump has to start almost every time a tap opens. That rapid on-off is short-cycling.
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What makes a well pump short-cycle
A plumber will usually work through these, roughly from most to least common:
- Lost air charge. Tanks slowly lose air over time. With less air, the tank holds less usable water between starts, so the pump comes on sooner and more often.
- A waterlogged tank or failed bladder. If the bladder or diaphragm has split, water fills the space where the air should be. A tell-tale sign is water, rather than air, coming out of the air valve on top of the tank.
- Pressure switch trouble. Worn contacts, a switch set too narrow, or a small port underneath it clogged with sediment or iron. Groundwater around Kettleby and Schomberg tends to be hard and can carry iron, which is hard on switches and fittings.
- A leak or a fixture that never stops. A running toilet, a dripping yard hydrant, a leaking line to a barn or garage, or a softener or iron filter stuck in its regeneration cycle all draw water quietly and keep the pump starting.
- A check valve letting water fall back. If pressure drops and the pump restarts with every tap closed, water may be draining back down the well.
- A tank that was always too small for the pump's output.
One exception: some newer systems use a constant-pressure pump controller, which is designed to run differently from a standard switch-and-tank setup. If yours has a control box with a display near the tank, mention it.
What you can safely check yourself
A few observations help a plumber a great deal. The electrical side is not one of them.
- Watch the gauge while a tap runs. Note the pressure when the pump starts and when it stops, and roughly how many seconds pass between starts.
- Knock on the side of the tank. The upper part of a bladder tank normally sounds hollow. If it sounds solid all the way up, the tank may be waterlogged.
- Look for leaks. Listen for toilets refilling on their own, and check yard hydrants, outbuilding lines and treatment equipment.
- Check the sediment filter if you normally change the cartridge yourself. A clogged one causes low pressure, though it is not usually what makes a pump short-cycle.
Do not take the cover off the pressure switch. It carries household voltage, often 240 volts, even when the pump is not running. Adjusting or replacing the switch is work for a plumber or a licensed electrician. If the pump runs without stopping, or there is no water at all, switch the pump off at its breaker so it does not run dry, and get help.
Checklist: what to note before you call
- That you are on a private well, and whether it is drilled or dug, if you know.
- The cut-in and cut-out pressures from the gauge, and the seconds between pump starts.
- The tank's age or install date, often on its label, and when the system was last serviced.
- Whether water comes out of the air valve on top of the tank.
- Any treatment equipment: softener, iron filter, UV or reverse osmosis.
- Whether it started after a power cut, a dry spell or other plumbing work.
- A photo of the tank, switch and gauge from the outside.
When to call a plumber
Short-cycling does not fix itself, and it rarely stays mild. Book a visit if any of these are true:
- The pump starts every few seconds while water runs, or restarts with every tap closed.
- Pressure fades halfway through a shower or swings widely.
- Water comes out of the tank's air valve.
- The switch buzzes, chatters or smells hot. Switch the pump off at its breaker if you can do so from a dry spot.
- You have no water at all.
What a fix costs depends on what is found: whether the tank can simply be recharged or needs replacing, the size of the new tank and where it sits, whether the switch, gauge and fittings are replaced at the same visit, and access in the basement or well pit. Prices vary from house to house, so ask the plumber to explain what is driving theirs.
It also matters where the problem is. Pressure tanks, switches, gauges, house plumbing and water treatment are plumbing work. Drilling, casing repair and decommissioning a well are regulated in Ontario and done by licensed well contractors, and if the trouble turns out to be down the well, such as a failed submersible pump, that part may need a well contractor. More on how the two fit together is on our well pressure tank page, and the same issues come up across King City and the rest of the township.
Frequently asked questions
Can I just add air to my pressure tank?
If the bladder is intact and the tank has only lost some of its charge, recharging can help. It has to be done with the pump switched off and the tank emptied of water pressure, with the air set slightly below the pump's cut-in pressure. If water comes out of the air valve, the bladder has failed, extra air will not last, and the tank needs replacing.
How long can a pump short-cycle before it is damaged?
There is no fixed answer. Each start heats the motor and wears the switch contacts and starting parts, so the longer it goes on, the more likely the repair includes the pump. Treat it as a repair to book soon, not a quirk to live with.
Will a bigger pressure tank help?
Often, yes. A larger tank holds more water between starts, so the pump runs longer and starts less often. The right size depends on your pump's output and how the house uses water, which a plumber can work out on site.
If your pump is short-cycling, the short form is free to use and sends your request to one local plumber who covers King Township.