What the pump is telling you
| What you notice | Likely causes | |
|---|---|---|
| Short bursts with nothing on | The pump starts, stops, starts again with every tap closed | A dripping tap or running cistern, a leak in the tank pipework, or a non-return valve that no longer holds |
| Runs but no water | Motor runs, little or nothing comes out | Tank empty, a blocked inlet strainer, or the pump has lost its prime |
| Will not start | Silence when a tap opens | No power, a tripped safety switch, dry-run protection has cut it out, or a failed controller |
| Weak or surging flow | Pressure rises and falls at the tap | A worn pressure controller, a waterlogged pressure vessel, or air getting into the suction side |
| Very noisy | Rattling, screaming or grinding | Worn bearings, cavitation from a starved inlet, or the pump loose on its base |
Safe checks before you call
Look at the tank level
An empty or nearly empty tank is the most common reason a pump stops delivering. If your system has a mains changeover, check it has switched across.
Check the power
See whether the pump's plug is in and its circuit at the switchboard has not tripped. If it trips again, leave it off and call for help.
Close every tap and listen
If the pump still kicks in every so often, water is escaping somewhere. Check toilets, garden taps and the ground along the tank pipes.
Note the make and model
The label on the pump, plus a short video of the noise or the cycling, helps a plumber judge whether it is a repair or a new pump before they arrive.
What a plumber will do
A plumber will check the suction side first: the tank outlet, any strainer or foot valve, and whether air is getting in. Then the pump itself, the pressure controller or switch, and the non-return valve that stops water draining back into the tank when the pump stops.
Common fixes are a new pressure controller, a cleaned or replaced strainer, re-priming the pump, or replacing a valve. If the motor or bearings have gone, a new pump is usually the better choice. The plumber will match it to the number of fixtures it feeds and the height and distance it has to push water.
Many tank systems switch to mains water when the tank runs low. If yours has a changeover device, the plumber will check that it switches cleanly both ways and that the backflow protection between tank and mains is intact. If the house needs topping up from the mains more often than it should, the problem may be the changeover rather than the pump.
Where your part stops
You can
- Keep the pump covered and ventilated, out of direct sun and rain.
- Clean an inlet strainer that is designed to be opened by the owner, with the pump switched off.
- Fix any dripping tap or running toilet the pump is feeding: see running toilets.
- Before any work on pipes that connect to the house, read what you can do yourself for your state.
Leave to a licensed plumber
- Replacing the pump, controller or valves.
- Re-plumbing the suction or delivery pipes.
- Any work on the mains changeover or backflow device.
- New wiring or a new power point, which is a licensed electrician's job.
Licence and paperwork
If the work touches a backflow device, the paperwork can change. Replacing one in Western Australia is not minor work. A notice goes in at least 24 hours before the job starts, and a certificate of compliance should follow within 5 working days. South Australia includes backflow device work in its electronic certificate of compliance rules. For the rest, see our compliance certificate guide.
Questions to ask the plumber
- Is it the pump, the controller or something in the pipework?
- Is a repair worth it on a pump this age, or should it be replaced?
- Is the new pump sized for the fixtures and the height it has to push?
- Will you check the mains changeover and the backflow device while you are here?
What we would do
Rule out the simple things first: an empty tank, a tripped circuit, a dripping tap. If the pump keeps cycling with everything closed, get it looked at soon, because short-cycling wears out a pump quickly. If it is old and noisy, put the money into a correctly sized new pump rather than a second repair. A plumber who works on tank systems often will check the changeover and backflow protection at the same visit.