Many pump problems come down to one small part, and the one people ask for most is a pressure switch for water pump systems on tanks and boreholes. Others fail just as often: capacitors, float switches, non-return valves, mechanical seals and probes. The right spare is often cheaper than a new pump, but the wrong one causes new problems, and anything on mains power is work for an electrician. Send one request with the pump and the part, ideally with a photo, and we pass it to independent pump shops and suppliers near you, who quote you directly.
Pressure switches and pressure controllers
A pressure switch starts the pump when the pressure in the pipes drops as a tap opens, and stops it when the pressure reaches the cut-out setting. It works with a pressure tank, which holds a little water under pressure so the pump does not start every time. A pressure controller (a flow switch) starts the pump when a tap opens and stops it when the flow stops, often without a tank, and many include dry run protection. When either fails, the pump may not start, may run without stopping, or may start and stop quickly. Fast cycling is often the tank, not the switch: check its air pre-charge. A pressure gauge beside the switch makes fault finding easier.
Capacitors, and can a pump run without one?
A single phase motor cannot start by itself: it needs a capacitor to get it turning, and some motors use both a start and a run capacitor. So no, a single phase submersible pump cannot run without a capacitor. On a 2 wire pump it sits inside the motor; on a 3 wire pump it is in the control box above ground. When it fails, the pump hums and does not start, or trips, and left like that the motor can burn out. Three phase motors do not need one. A replacement must match the rating printed on the old one, and because capacitors can hold a charge after the power is off, let an electrician or repairer change it.
Valves, floats and probes
- Non-return (check) valve: stops water running back down the pipe. A stuck one blocks the flow; a leaking one lets the pump restart for no reason.
- Foot valve: at the end of a surface pump's suction pipe, keeps the pump primed.
- Float switch: starts and stops a pump on the water level in a tank or sump.
- Dry run and level probes: tell the control box when the water in a borehole runs low.
- Borehole caps and splice kits: see pump cable and pipe.
Seals, impellers and bearings
Inside the pump, the wearing parts are the mechanical seal on the shaft, the bearings and the impellers. A leaking seal shows as a drip under a surface pump, worn bearings grind, and worn impellers mean less flow and pressure. Spares for common pumps are usually available from pump shops, but they must match the model, so take the old part or a photo of the rating plate. Fitting seals and bearings means stripping the pump, which many owners leave to a workshop; see water pump repairs.
What to put in your request
- Pump type and motor size in kW
- Single or three phase, 2 wire or 3 wire
- A photo of the old part and the rating plate
- How many of each part you need
- Whether you need it fitted as well
Pump Spares for homes, farms and businesses
- Homeowners: a new pressure switch for a booster pump on a water tank
- Smallholdings and plots: a spare capacitor and float switch kept on the plot for the borehole
- Farms: valves, probes and splice kits stocked for boreholes far from town
- Complexes, estates and body corporates: pressure controllers and gauges for a complex's booster set
- Offices, shops, hotels and lodges: seal and bearing kits for hotel pool and pressure pumps
- Factories, plants and depots: spare impellers and seals for process pumps before a planned shutdown
- Mines and quarries: wear parts and float switches for sump and transfer pumps
- Municipalities, schools and clinics: probes, capacitors and valves for village borehole panels
- Contractors and drillers: a plumber buying pressure switches and valves for tank installs
Frequently asked questions
Do you sell pump spares yourselves?
Can a submersible pump run without a capacitor?
How do I know if my pressure switch is faulty?
Which capacitor do I need for my pool pump?
Pump Spares by province and city
- Johannesburg
- Pretoria
- Centurion
- Midrand
- Sandton
- Randburg
- Roodepoort
- Krugersdorp
- Randfontein
- Germiston
- Boksburg
- Benoni
- Kempton Park
- Alberton
- Vanderbijlpark
- Vereeniging
- Durban
- Pinetown
- Pietermaritzburg
- Richards Bay
- Newcastle
- Ladysmith
- Gqeberha (Port Elizabeth)
- East London
- Kariega (Uitenhage)
- Mthatha
- Cape Town
- Bellville
- Paarl
- Stellenbosch
- George
- Worcester
- eMalahleni (Witbank)
- Middelburg
- Secunda
- Mbombela (Nelspruit)
- Rustenburg
- Brits
- Klerksdorp
- Potchefstroom
- Mahikeng
- Polokwane
- Tzaneen
- Kimberley
- Upington
- Bloemfontein
- Welkom
- Sasolburg