Start Faults · Gauteng
Generator Not Starting.
Find Why, Then Repair It.
A generator that will not start usually has a flat battery, a starter fault or a controller that is blocking the start. We find out which on site across Gauteng, testing the battery, starter, fuel and control panel before we change any parts.
Callout fee waived when you accept our written quote. 1-year workmanship guarantee. See prices
- Onsite start-fault diagnosis
- Diesel and petrol units
- Battery, starter and panel checks
- Open 24/7, on site within 1 hour
The Fault
What causes a generator not to start?
A generator that will not start usually has a flat battery, a starter fault, or a controller that is blocking the start. Here we mean a set that stays silent, clicks, or never cranks. A standby set that only fails when the mains drops, or an engine that fires and then shuts down, has a different fault. Treating them all as one “won’t start” problem is how good parts get replaced.
Before any repair, we check whether the engine is being asked to start at all. A flat battery, a pressed emergency stop, a tripped low-oil switch or a controller that is not sending a start command can all look like a failed engine. If the starter is not engaging, we do not start with the fuel system.
We test the battery with a meter, not by ear. A fully charged 12 V lead-acid battery reads about 12.65 V after resting (Battery University). In a standard load test, a healthy battery holds above 9.6 V while it delivers half its cold-cranking rating for 15 seconds (Discover Battery). A battery that falls short on either check can explain a click by itself.
When the starter does engage, we move on to fuel delivery, safety interlocks and the controller’s inhibit signals. Diesel standby sets can shut down on low oil pressure or high temperature even while cranking if a sender is faulty. Petrol sets more often fail at the carburettor, the spark plug or stale fuel in the bowl.
We work on home standby generators and commercial backup sets across Johannesburg, Pretoria, Sandton and the wider Gauteng area. We diagnose on site, explain the fault in plain terms, and give you a written quote before any work starts.
Generator will not start?
Call or WhatsApp 082 057 4605 for onsite diagnosis across Gauteng.
Fault guide
Generator not starting: what it can mean and what to do
A generator that will not start usually has a battery, starter or controller fault. We first check whether the engine turns at all, because that tells us which path to follow. This guide separates what you can safely notice from what a qualified technician tests. One symptom never proves that a particular part has failed.
Symptom, likely cause and repair
Find the line closest to what you see. The cause is the most likely one, not a diagnosis: testing confirms it before any part is replaced.
| What you see | Likely cause | Usual repair |
|---|---|---|
| Nothing happens when you press start | A flat battery, loose or corroded terminals, or a blown start fuse | Battery and charging repairs |
| A click or rapid clicking, no engine movement | A weak battery or a failing starter motor or solenoid | Starter motor repairs |
| An alarm on the screen and no start attempt | The controller is in Off or Manual, an emergency stop is latched, or a shutdown has not been reset | Controller repairs |
| The engine turns slowly, then gives up | A battery near the end of its life, or poor connections | Battery and charging repairs |
| Starts on the panel but not when the mains fails | The automatic start signal or the transfer switch | ATS repairs |
01
What you may notice
- Nothing happens when you press start or turn the key
- A single click, or rapid clicking, with no engine movement
- The controller shows an alarm and will not try to start
- The engine turns very slowly and gives up
02
Possible causes
Any of these can produce the same symptom. Testing decides which one applies.
- A flat or failing starter battery, or loose or corroded battery terminals
- A starter motor or starter solenoid fault
- The controller in Off or Manual, an emergency stop latched, or an unreset shutdown alarm
- A blown fuse or a wiring fault in the start circuit
- A low oil level or other protection that blocks the start
- On petrol sets: the fuel valve or engine switch off, or the oil-alert system stopping the start
03
What you can safely check
Look and note only, from outside the canopy. Do not open panels, covers, fuel lines or the cooling system.
- Does the engine turn at all, turn slowly, only click, or do nothing?
- What does the controller display say? Photograph the screen or warning lights.
- Is the controller in Auto, Manual or Off, and is an emergency stop pressed in?
- When did it last run, and did it stop normally?
- On a portable set, is the fuel valve open and the engine switch on?
04
Stop using the generator and call if you notice
- A burning or electrical smell, smoke or heat from the battery or starter
- A swollen, leaking or hissing battery
- Fuel leaking or a strong fuel smell around the set
If it is safe to reach, stop the generator with its normal stop control or emergency stop, keep people away, and call a technician.
05
What a qualified technician typically tests
These are technician checks, not steps to try yourself. Several involve live electrical measurement, fuel or pressurised systems.
- Battery voltage at rest and while cranking, and a load test of the battery
- Voltage drop across the cables, earth strap and starter solenoid
- Start-signal path from the controller to the starter
- Active and logged alarms, emergency-stop circuit and shutdown inputs
- Oil level and the protection that is blocking the start
06
Common repair categories
The repair follows the test result. These are the services this symptom most often leads to.
07
What to send when you book
- Your suburb and how we reach the generator
- Make, model and kVA from the data plate (a photo is ideal)
- Fuel type: diesel, petrol or gas
- Exactly what happens when you press start: nothing, a click or slow cranking
- A photo of the controller screen or warning lights
08
Related faults and services
Not sure which symptom fits? Try the generator symptom finder.
Safety before you check anything
- Exhaust contains carbon monoxide, which you cannot see or smell. Run a portable generator outdoors only, away from doors, windows and vents, and never run any generator in a house, garage or other enclosed space.
- A standby generator set to automatic can start at any moment, when the mains fails or on its exercise timer. Keep the canopy closed and stay clear of fans, belts and the exhaust.
- Generator output, the changeover and the control panel can be live, and some parts hold stored electrical energy after shutdown. Leave panels, covers and wiring closed for us to open.
- The engine, exhaust and coolant stay hot after running. Never open a radiator or coolant cap on a hot engine.
- Do not refuel a running or hot generator. If you smell gas at a gas-fuelled set, do not operate switches; leave the area and contact your gas supplier.
Carbon monoxide guidance: US Consumer Product Safety Commission: Generators and engine-driven tools (carbon monoxide).
Send the details on WhatsApp
This opens WhatsApp with a short message already typed: brand, model, capacity, symptoms and suburb. Fill in what you know and send it. Blank lines are fine.
- The data-plate photo is added inside WhatsApp after the chat opens: tap the attachment or camera icon and choose the photo. A link cannot attach the photo for you.
- Take the photo only when the generator is switched off and has cooled down. Do not reach over or into a running or hot generator, and keep away from the exhaust.
- A standby generator set to automatic can start by itself when the mains supply fails. If you are not sure how it is set, photograph the plate from a distance or send a photo of the whole set instead.
Typical repair costs for this fault
Published ranges, last reviewed October 2026. The callout is R400 – R700 in business hours and R700 – R1,400 after hours, and it is waived if you accept the quote. Your written quote after diagnosis is the price that applies.
- Starting fault diagnosis and repair
- R600 – R3,500
- Battery replacement
- R900 – R2,800
- Starter motor repair or replacement
- R1,400 – R4,000
Step 9: book a diagnosis visit.
How We Diagnose
Start-circuit checks before parts
- 01
Confirm the start command
We check the battery voltage, the emergency stop, the isolators and whether the controller is actually calling for a start.
- 02
Test the cranking circuit
We measure starter current, solenoid operation and the earth paths before we touch the fuel system.
- 03
Check fuel and safety interlocks
If the engine is asked to run but will not fire, we test fuel delivery, the solenoids and the oil and temperature senders.
- 04
Quote, repair and prove the start
You get the scope in writing. After the repair, we prove manual starting and, where fitted, automatic starting.
Diesel and Petrol
The first split is crank versus no crank
Diesel and petrol no-start faults share battery and control causes, then split quickly. Diesel standby sets often fail on a cold morning because glow plugs, a lift pump or contaminated fuel stop the engine from firing. Petrol sets that stand unused for weeks more often have a gummed-up carburettor.
If the engine turns strongly but never fires, the fault is usually fuel or ignition, and our guide to generators that crank but will not start covers it. If there is no crank at all, stay with this diagnosis.
Diesel standby
Glow plugs, lift pumps, fuel solenoids and controller inhibits
Petrol units
Spark, stale fuel, carburettor bowls and recoil or electric start
Auto-start sets
AMF/ATS command, start relays and transfer inhibit
When to call
After a few failed attempts. Stop cranking and call us
Common Questions
Generator not starting — questions we hear
Why does my generator not start when the power goes off?
If it will not start from the panel either, the cause is usually the battery, the starter, fuel or a shutdown. If it starts in manual and only fails when the mains drops, the fault is in the automatic start.
Can low oil stop a generator from starting?
Yes. Many sets will not crank, or will crank and shut down at once, if the oil-pressure switch is open. Sometimes the oil really is low. Sometimes a faulty sender or wire is protecting the engine against a false reading.
Should I keep trying the starter?
No. Repeated cranking flattens the battery, overheats the starter and can flood a petrol engine. Stop after a few attempts and let us diagnose the start circuit on site.
Is a generator that clicks once a battery problem?
Often, but not always. A click can come from a weak battery, a poor earth, a failing starter solenoid or a start relay in the panel. We measure the voltage at the terminals while it tries to crank, and that tells us which.
Why will my generator not start?
Usually because of the battery, the starter, fuel, a low-oil shutdown, a pressed emergency stop or a controller that will not send a start. A silent set and a set that cranks are different jobs, so the first thing we ask is what you hear.
Can a fuel problem stop a diesel generator from starting?
Yes. A blocked filter, air in the lines, contaminated diesel or a faulty fuel solenoid can leave a diesel cranking without firing. We check those before we condemn an injection pump.
When should I book a generator technician?
Book as soon as a few start attempts have failed, an alarm has latched, or you need the set for a building. We are open 24/7 and arrive within 1 hour for breakdowns. Call 082 057 4605 with your suburb, the fuel type and what the controller shows.
Still unsure what the fault is? Call or WhatsApp 082 057 4605 for onsite diagnosis.
Related Services
If the engine turns but never fires
- Starter Motor Repairs Click, slow crank or no crank
- Battery Not Charging Goes flat between starts
- Battery Charging System Repairs Charger, cables and isolators
- Fuel Solenoid Repairs Fuel shutoff on a diesel
- Not Auto Starting Fails only when the mains drops
- Starts Then Stops Fires, then shuts down
- Generator Repairs Full onsite repair service
- Emergency Callouts Breakdowns at any hour
- Generator Servicing Service that prevents the next no-start
- Not Used for Months A set that stood through months without load shedding
- Cranks But Won't Start Turns over, will not fire
- Control Panel Repairs Start relays and AMF faults
- Fuel System Repairs Solenoids, filters and supply
- Contact Call or request a quote
Service Areas
No-start callouts across Gauteng
We diagnose generators that will not start across Johannesburg, Pretoria, Sandton, Centurion, Midrand and surrounding East Rand and West Rand areas.
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 Diagnosis
Need the set starting again?
Tell us whether it clicks, cranks or stays silent, plus the brand and your suburb. We come to you anywhere in Gauteng.
- 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. For a breakdown we arrive within 1 hour.
- 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.