Standby generators · Backup sets kept ready to start
Standby & Emergency Generator Servicing and Maintenance
A standby, or emergency, generator must start by itself and take the load when the mains fails, at a home, estate, clinic or office; standby generator servicing and maintenance keep it ready. If yours has failed right now, go to emergency generator repair: we are open 24/7 and arrive within 1 hour for a breakdown. Planned visits are booked for a time that suits you, with a free written quote first.
Callout fee waived when you accept our written quote. 1-year workmanship guarantee. See prices
- Battery, fuel and start tests
- Controlled transfer tests, agreed first
- 1-year workmanship guarantee
- Onsite across Gauteng

Why low-hour sets fail
What keeps an emergency generator ready between outages
When a backup set stays silent as the lights go out, the cause is rarely a major failure. It is usually a battery run flat or a charger that stopped charging, a controller switched out of Auto, an emergency stop still pushed in, fuel that has gone stale or run out, or a shutdown alarm from the last run that nobody cleared. None of these shows while the mains is on, so they are found on a schedule rather than on the night.
Oil, fuel, coolant and batteries age with the months whether the engine turns or not. A set that almost never runs is therefore serviced at least yearly, or at its maker’s hour interval if that point comes sooner.
The work is done while the mains is on and the set can be spared briefly. A test that moves the whole building onto the generator is agreed beforehand with the person responsible for the site, and occupants are told before it happens.
Maintenance contracts and service level agreements (SLAs) are customised for each client. We inspect and assess the generator, its condition, capacity and usage, and your requirements, then quote the plan in writing. There are no fixed packages or prices.

On every visit
The readiness checks on each visit
Each check answers one question: will this set start, change over and carry the load the next time the mains drops?
Charger float and battery under load
The starting battery is load-tested and the mains charger’s float output measured. A battery that barely cranks today will not after weeks on standby.
Alarms, Auto mode and the exercise timer
We go through the alarm log and find why each entry happened, leave the set in Auto, and check the exercise timer where the controller has one.
Fuel age and water in the separator
We note how old the fuel is and how full the tank sits, then drain the separator and look for water or slime that would choke a filter mid-outage.
Coolant, and the block heater where fitted
Coolant level and strength, hoses and clamps are checked with the engine cold. Where a block heater keeps the engine warm for starting, we confirm it works.
Air inlets and the canopy
Leaves, nests and stored boxes block louvres and radiator airflow. We clear inlets and outlets and check that canopy doors and seals close properly.
Start signal and changeover as a controlled test
We give the set a start signal as if the mains had dropped, then watch the changeover and the hand-back. A whole-building transfer happens only when the site agrees.
Voltage and frequency on load
With the set carrying load we read voltage and frequency, because a set that starts but sags under load will not hold the building up.
The record of the visit
Date, running hours, work done, parts fitted, readings and findings, kept per set so the next visit starts from the facts.
Next due by hours and by date
We write down the hour reading and the date at which the next visit falls due. The earlier of the two sets the booking.
Maintenance programme
How a standby maintenance programme is set up
A programme turns occasional visits into a plan for one set or several, written around what each generator has to carry.
01
Assess the set and the site
We look at the generator, its controller, transfer switch, battery and fuel, and at what it must carry when the mains fails.
02
Agree the visit schedule
Calendar visits for a set that mostly waits, with an extra visit when long outages have added running hours.
03
Agree what each visit covers
The readiness checks, any service items due, and whether a building transfer is included or kept to a controlled changeover test.
04
Decide when a load bank test joins the plan
When the building load is too light or too critical to prove the set, a load bank test is added. Our cost guide puts it at R2,800 to R5,500.
05
Agree access and notice
Who meets us, how we reach the set, and how much warning occupants need before a transfer test.
06
Keep records per set
Each generator keeps its own visit history, so a site with more than one set can see which is due and what was found.
If the generator breaks down between visits, contract clients are scheduled ahead of new callouts. Either party can end a contract with 30 days’ notice. For the published intervals behind a schedule, see service intervals by duty and how often to service a generator; for proving a set on a known load, see load bank testing.
Warning signs
Warning signs on a standby generator
You can notice all of these without opening the canopy. The owner’s own check is short: the controller showing Auto and a clear alarm screen.
It did not start on its own last time
The set stayed quiet in the last outage, or only ran once someone started it by hand.
It ran, but the building stayed dark
The engine started and the power never arrived, which points at the transfer switch or its signal.
An alarm stays on, or the exercise run has stopped
A lamp or message that will not clear, or a regular exercise run you no longer hear, means the controller needs reading.
A click instead of cranking
A click, or a charger indicator that has gone out, usually means the starting battery is no longer being kept up.
Fuel older than the last long outage
Diesel bought for one long outage and left in the tank since has had months to collect water.
Breakers trip as big loads start
A set that trips when lifts, pumps or air-conditioning start may be undersized for the load or not delivering its output.
If the set has already failed and you need it working now, go to emergency generator repair. For a set that will not start by itself, the auto-start fault guide explains what we test.
Common Questions
Questions about standby generator maintenance
What stops a standby generator from starting when the power fails?
Usually something small that went unnoticed: a flat battery or a failed charger, the controller left out of Auto, an emergency stop still pressed, stale or finished fuel, or a shutdown alarm nobody cleared. Readiness checks find these while the mains is still on.
How often should a standby generator be test-run?
Follow the maker’s schedule for your set and the plan agreed for your site. Many controllers run a regular automatic exercise, and a run on real load tells you more than an idle one. Sites working to the US standard NFPA 110 use its monthly loaded figure, which our service intervals guide explains.
Does an emergency generator need servicing if it hardly ever runs?
Yes. Oil, fuel, coolant and the battery age with time as well as hours, so a low-hour set still gets a service at least once a year, or at the maker’s hour interval if that comes first. Generac, for example, publishes a yearly routine for its home standby sets.
My generator has broken down right now. Is this the right page?
No. This page covers keeping a standby set ready. For a set that has failed, see our emergency generator repair page or call 082 057 4605: we are open 24/7 and arrive within 1 hour for a breakdown.
Do you test the automatic transfer switch during maintenance?
Yes, as a controlled test: the set gets a start signal, takes over and hands back to the mains while we watch each step. A transfer that puts the whole building on the generator is agreed with the site first, with notice for the people inside.
What is in a standby generator maintenance plan?
The visit schedule, the checks on each visit, whether building transfers or load bank tests are included, how records are kept and how a breakdown between visits is handled. Each plan is written for one site after we have assessed its generator.
Can our clinic, office or estate generator go onto a maintenance contract?
Yes. We assess the set and quote a contract for that site. If it fails between visits, a contract site is put ahead of new callouts in the queue, and repairs on a covered set may be charged at preferred labour rates, still quoted in writing first.
Should the starting battery be replaced on a schedule?
We replace it on condition rather than on a fixed date: the load test at each visit shows when it is weakening, and we tell you before it lets the set down. Battery replacement is typically R900 to R2,800 on our cost guide.
Still unsure what the fault is? Call or WhatsApp 082 057 4605 for onsite diagnosis.
Related Pages
Readiness, transfer switches and breakdowns
- Emergency Generator Repair The set has failed now
- Maintenance Contracts & SLAs How a contract is assessed and quoted
- Not Starting Automatically Diagnosing a missed auto-start
- Not Used for Months Recommissioning after a long standstill
- Body Corporates and Estates Shared standby sets for gates, lifts and pumps
- Load Bank Testing Prove the set on a known load
- ATS Repairs Faults in the transfer switch
- Battery Charging System Charger and starting battery faults
- Standby vs Prime What the duty ratings mean
- Commercial Servicing & Maintenance Offices, shops and complexes
- Diesel Servicing & Maintenance Servicing diesel sets of every size
- Generator Controllers Alarms, Auto mode and settings
Service Areas
Servicing & maintenance across Gauteng
Servicing and maintenance visits are booked for a time that suits you. Choose your area for the suburbs, site types and plans we cover there.
- Generator servicing & maintenance in Johannesburg
- Generator servicing & maintenance in Sandton
- Generator servicing & maintenance in Randburg
- Generator servicing & maintenance in Midrand
- Generator servicing & maintenance in Roodepoort
- Generator servicing & maintenance in Pretoria
- Generator servicing & maintenance in Centurion
- Generator servicing & maintenance on the East Rand
- Generator servicing & maintenance in Kempton Park
- Generator servicing & maintenance on the West Rand
What to send before we attend
These details help us plan the visit and bring the right parts. Send what you can on WhatsApp; if you can’t find the model number, we still book the visit.
- Location
- The suburb or site, so the visit can be booked in the right area.
- Make and model
- The generator brand and model, if they are known.
- kVA
- The size printed on the data plate.
- Fuel type
- Diesel, petrol, LPG, natural gas, or dual-fuel.
- Controller model
- The module name on the panel, when it is visible.
- Fault or alarm
- What the set does, and any text on the screen.
- Photos
- The generator, the data plate, and the controller or alarm. Send these on WhatsApp.
Book a Visit
Arrange standby generator maintenance
Tell us the site type, the kVA, the controller make, whether a building transfer test is allowed and who gives access. A photo of the controller screen helps us prepare.
- Call
- 082 057 4605
- Message us on WhatsApp
What happens next
- We reply with questions about the generator, or to book a visit.
- A technician comes to you at the booked time.
- The fault is diagnosed on site and you get a written quote. No work starts until you accept it.
Charlie, lead technician: Degree in Mechanical Engineering, Degree in Electrical Engineering, Diesel Plant Fitter. Generator specialists since 2000.