Why Won’t My Heater Start?

Common Causes and What to Check Before You Call a Technician

It’s a cold Melbourne morning, you hit the controller, and… nothing. Heater won’t fire up. Here’s what might be going on and what you can check yourself before you pick up the phone.

Older Systems (25+ Years Old): (the good old days) :)
If your heater is from the nineties or earlier, there’s a good chance it uses a pilot light. If it won’t start, the pilot might’ve gone out, this can happen especially after a long break or a windy night. Relighting it can sometimes solve the problem, but if it keeps going out, it might be time to get a technician out there. Generally there are instructions to relight the pilot on the inside of the service panel door. If you follow the directions and it still isn’t working absolutely give us a call.

Thermocouple and Pilot

Newer Systems (Under 25 Years):
Modern heaters use electronic ignition and safety boards (PCBs). If yours doesn’t start, the system might be detecting a fault—anything from a blocked filter a sensor issue or it could be something very serious. Most newer systems won’t let you relight or reset anything manually if there’s a safety trip.

Auto Ignition systems

What Homeowners Can Check:
– Power: Make sure the power switch near the unit is on.
– Controller: Double-check settings—sometimes it’s just on the wrong mode or temperature.
– Filter: Dirty filters are a common cause. Go to your return air Vent (the biggest one), check if there is a filter - If there is, Pull it out and clean it if there is any dust.

- Open All your vents: If you have vents closed this can cause an over heat issue in the system. Open all your vents to make sure the system can keep its self cool and your house warm.
– Reset: Try switching the heater off at the power point, wait a minute, and turn it back on. Sometimes a simple reset is all it needs. Whilst that may get you through the night, the heater is trying to tell you “things aren’t right” and you should contact a technician as soon as possible.

If your system still won’t start after these steps, don’t keep trying! If the system still doesn’t work after a reset, there could be a bigger issue at play and you could make things a lot worse. That’s when it’s time to call a licensed technician. I want to reiterate that. one Reset is ok, two resets is one too many!

If you’re in Melbourne and your heater won’t start, book a service with Pro-Tech Heating and Cooling. We’ll get you back up and running safely, with honest advice on repairs or upgrades.