Heater won't ignite at all
No spark, no gas, no flame. Different fault to delayed ignition — start here.
Common fault · Don't ignore it
Gas heater banging when it lights? Stop running it.
That bang or boom isn't normal — it's called delayed ignition. Gas builds up in the combustion chamber for a few seconds before the spark catches, then the whole pocket lights at once. It's loud, it's startling, and it slowly cracks the heat exchanger. Easy fix if caught early. Expensive new heater if ignored.
Same-day metro Adelaide
Igniters in the van
CO test included
Licensed gas fitter
60–90 min on site
$149+$110 typical
Heat exch check
What's happening
Delayed ignition — the engineering bit
When a gas heater fires up, the gas valve opens and the igniter sparks roughly at the same moment. In a healthy heater, the spark catches the gas within a fraction of a second and you get a quiet "whoof" as the burner lights. You barely hear it.
When something is off — usually a weak spark, a dirty pilot, or low gas pressure — the spark can't catch the gas straight away. The valve keeps feeding gas while the system tries to ignite. After a couple of seconds of that, you've got a small pocket of gas sitting in the combustion chamber. When the spark finally bites, all of that gas lights at once. Bang.
The bang is a small, contained explosion. It's not enough to blow the heater apart in one go, but it puts a sharp pressure shock on the heat exchanger panel every single time the heater starts. Repeat that 5–10 times a day for a winter and you get hairline cracks in the heat exchanger. Once the heat exchanger is cracked, combustion gases — including carbon monoxide — start leaking into the air your fan blows around the house.
Safety check
Is this dangerous?
Yes — more than people realise. Banging itself won't kill anyone tonight. But the damage it does over weeks and months is exactly the kind of slow-build heat exchanger crack that puts CO into Australian homes every winter.
There's also a small but real risk of the bang being big enough to shift the flue panel, blow the front cover open, or — on rare older units — start a fire if there's combustible material near the heater. The longer you let it bang, the worse all of these get.
If you smell gas at any point, stop and call 1800 427 532 (SA Gas Emergency) first, then ring us. If anyone has headache, nausea or dizziness when the heater runs, treat that as a CO warning — get them out, ventilate, ring 000 if symptoms are bad.
Right now
What to do in the next 5 minutes
1
Stop running the heater
Turn it off at the controls and the wall. Each bang is doing damage — don't add more.
3
Use a backup heat source
Portable electric heater or reverse-cycle aircon for the night. Don't keep starting the gas one.
Diagnosis
What's likely causing it
- Weak ignition electrode (most common). The spark is too feeble to light the gas instantly. Replace the igniter — $110–$180 fitted. Common on Braemar, Brivis and Bonaire ducted units.
- Dirty pilot or pilot orifice. Pilot flame is too small to act as a strong ignition source. Clean and re-set — covered in the standard service.
- Poor gas/air mix. Burner ports clogged, venturi blocked with cobwebs, or the air shutter has slipped. The mixture goes too rich, ignition stalls. Cleaned and tuned during service.
- Low gas pressure. Could be a regulator issue at the meter or a kink/restriction in the gas line. We pressure-test with a manometer on site.
- Failing gas valve. The valve is slow to open, or doesn't shut off cleanly between cycles, leaving gas in the chamber. $400–$650 fitted, only on heaters where it's worth doing.
DIY?
Can I fix it myself?
No. Adjusting gas pressure, replacing igniters, or touching the gas valve all involve gas-side work that has to be done by a licensed gas fitter under SA's Plumbing, Gas and Electrical Services Act 1995. Doing it yourself voids your insurance, and if the bang gets worse you're on the hook for any damage.
What you can do safely: vacuum any visible dust around the bottom of the heater, make sure nothing is leaning against the air intake, and stop running it until we arrive.
When to call
Call us today if
- The heater bangs, booms, or "thumps" when it lights
- The bang is getting louder or more frequent
- You can see soot or scorch marks around the burner panel
- The flame is yellow or lazy after it lights
- The heater hasn't been serviced in 2+ years
Honest pricing
How much will the repair cost?
2026 Adelaide pricing, GST included, no call-out fee:
- Service + igniter replacement: $260–$330 (typical fix)
- Pilot rebuild: $220–$280
- Gas valve replacement: $400–$650
- Pressure regulator adjustment / replacement: $180–$340
- Heat exchanger replacement: $1,400+ — usually means new heater
We diagnose first and tell you the total before starting. If we find heat exchanger damage from past banging, we'll show you the crack on a borescope — no fluff.
Response time
How quickly can you come out?
Same day across Adelaide metro if you ring before 10am. Banging gets bumped up our list because every additional ignition is doing measurable damage to the heat exchanger. Most jobs take 60–90 minutes on site — diagnose, replace the bad part, pressure test, CO test, done.
FAQ
Banging on ignition — common questions
It's delayed ignition — gas pools in the combustion chamber for a few seconds before the spark catches, then the whole pocket lights at once. Common causes: dirty pilot, weak ignition electrode, low gas pressure, or a failing gas valve.
Yes. It stresses and eventually cracks the heat exchanger, which leaks combustion gases (including CO) into your house air. Can also blow the flue panel off. Stop using the heater and book a fitter.
Dirty pilot or weak igniter: a $149 service plus a $110–$180 igniter usually does it. Gas valve replacement is $400–$650. Heat exchanger crack from long-term banging is rarely economic.
We strongly recommend you don't. Each bang does damage. If you have to, run it as little as possible and ventilate. Better to use a portable electric heater for the night.
Same-day across Adelaide metro. Banging is a priority callout. Most jobs are 60–90 minutes on site.
Related help
Other gas heater problems we help with
Yellow flame after it lights
Banging plus yellow flame is a serious combo. Read this next.
10 signs your heater needs repair
The full warning-sign list from 12 years on the tools in Adelaide.
Heater banging? Don't keep using it — book today.
Same-day across Adelaide metro. Igniters in the van. Heat exchanger inspection on every callout.