Generator Questions, Answered

We arrive within 1–2 hours, usually within 1 hour. Tell us where the generator is when you call so we can say when to expect the technician. If it failed during an outage, our emergency generator repair page explains what is safe to do while you wait.

Yes. We operate 24/7, every day of the year, so you can call at 2 a.m. on a Sunday as readily as on a Tuesday morning. Call or WhatsApp 076 434 7292.

Where the generator is, its make, model and kVA rating from the nameplate, and what it is doing: not starting, running without power, showing an alarm, smoking or leaking. An hour-meter reading and a photo of the controller screen help a lot; the photo gallery shows the labels and screens worth photographing. Our guide to preparing for a technician visit lists the rest.

Check the fuel level, that the emergency stop is not pressed in, that the controller is in automatic mode and whether the output breaker has tripped. With the set isolated, look for loose or corroded battery terminals and for leaks you can see from outside. Leave panels, wiring, fuel lines and the changeover to us, and stop cranking after a few failed attempts. See generator not starting.

Call or WhatsApp 076 434 7292, email info@onsitegeneratorrepairs.co.za, or send the form on our contact page. Routine servicing is booked for a time that suits you; a breakdown is treated as urgent.

We use them to reply to your enquiry and to arrange and record the work. Our privacy policy explains what we keep, why, for how long and how to ask us to correct or delete it.

Repairs fix a fault. Servicing is scheduled routine work: oil, filters, fluids, checks and a test run. Maintenance is the ongoing programme of services, inspections and test runs that keeps a generator ready.

At the running-hours interval in the engine manufacturer’s schedule, or once a year, whichever comes first. A standby set that only runs on test reaches the yearly date first; one that runs through load shedding most days can reach its hours interval within weeks. See service intervals and oil care.

Yes. Oil and coolant age in the engine, batteries self-discharge, rubber hoses perish and stored diesel picks up water whether the set runs or not. A standby generator left for a year without attention is the one most likely to let you down when the power goes. See standby generators.

A typical service replaces the engine oil and the oil, fuel and air filters, drains water from the fuel separator, checks coolant, belts, hoses, the battery and the charger, reads the controller’s alarm history and ends with a test run, under load where possible. The exact list depends on the engine: the service checklist shows it item by item, and generator servicing explains how we do it.

Yes. For homes, estates, businesses and industrial sites we agree a schedule of services, inspections and test runs for each generator, timed by its running hours and the calendar. See generator maintenance.

A no-load run proves the engine starts, not that it can carry your load. Diesel sets that run lightly for long periods also suffer from wet stacking, where unburnt fuel and soot collect in the exhaust. A run on the building’s own load, or on a load bank, shows whether the set holds its voltage and frequency at the load it will meet in an outage.

We Service & Repair All Generator Brands. That includes complete sets such as FG Wilson, Kipor and Honda, engines from Perkins and Cummins, alternators from Stamford and controllers from Deep Sea and ComAp. The brands page lists the makes we see most.

Yes. We work on petrol generators, portable and inverter units, gas generators running on LPG or natural gas, and diesel generators of every size.

From small portable units to large industrial sets: 1 kVA–20,000 kVA capability. Whether a generator runs a few lights during load shedding or a whole factory, the same approach applies: find the fault first, then fix it.

Add up the running load in kW, then allow for the biggest starting surge: the motors in borehole pumps, compressors and air conditioners draw several times their running current as they start. Convert to kVA (most diesel sets are rated at a power factor of 0.8, so 1 kVA gives about 0.8 kW) and leave headroom. The kVA sizing guide works through an example, and single vs three phase explains the supply side.

For long or frequent outages and bigger loads, diesel: it uses less fuel for each kWh, keeps better than petrol in storage, and diesel engines run longer between overhauls. Petrol suits small, occasional loads and costs less to buy, but stale petrol gums up the carburettor when a unit stands for months. Compare diesel and petrol generators.

Yes. Controllers from makers such as Deep Sea, ComAp and SmartGen, their sensors and wiring, and automatic changeover panels are all part of the work. See control panel repairs.

No. Free callouts and quotations: you do not pay for the technician to come out or for the quotation. Most faults are found on that first visit; if an intermittent fault needs a longer test run to catch it, we explain what that involves before going ahead. See what affects the cost.

It depends on what the diagnosis finds: the fault, the parts it needs, the size of the generator in kVA, its fuel type, access to the site and how urgently the work is needed. A tripped breaker and burnt alternator windings can both mean no power at the board, at very different costs, which is why we quote after finding the fault. Our repair cost guide explains each factor.

No. You see the quotation first, and work starts only once you approve it. The same applies to any extra work found along the way.

Yes. Our work carries a one-year warranty. Ask us to explain what it covers for your job when you approve the quotation.

Usually because they cover different work. Check whether the fault has actually been diagnosed or only guessed, which parts are listed, whether a test under load is included and what warranty applies. A low price for replacing a part that was never faulty is not a saving. See generator repairs for how we diagnose before we quote.