Why Your Oil Furnace Won’t Turn On

If your oil furnace won’t turn on suddenly, there’s no room to panic. If you heat with gas, our furnace won’t turn on checklist covers that system instead.

This happens often and in most cases, you can fix the issue by yourself.

Without further ado, let’s jump straight into the most common reasons why you’re facing this issue.

7 Most Common Reasons Why Oil Furnace Won’t Turn On

1. Oil is low

A lot of us tend to forget to fill the tank, so it’s very important to check the gauge and see if there’s any oil.

If your tank is lower than a quarter, then you’ll have to refill oil before running out of it completely.

My recommendation is to always fill the oil whenever it drops to around a quarter of the full tank.

2. Circuit breaker

Inspect your electric panel and check if the breaker for the furnace went off – if yes, simply switch it on.

Wait a few minutes to check if the furnace will start working again.

To be honest, this is probably the most common reason why an oil furnace won’t turn on, so make sure to check it.

Sometimes it could be that your whole circuit breaker went off and in that case, it’s good to seek professional help.

3. Check thermostat

Sometimes the thermostat sends the wrong signal, or it has been left set to cool instead of heat.

The best practice here is to set the thermostat a few degrees above the room temperature and see if it will make any difference.

Also, make sure that batteries are working fine and that there’s no dust and debris around wires.

4. Check the filters

More often than not, filters can collect a lot of dirt and debris which causes the system to stop working efficiently as before.

The filter is located inside the metal compartment next to the blower.

Check the filter every month and change it at least every 3 months to keep the best performance.

5. Motor stopped working

When the blower stops working, it prevents warm air from leaving the machine and entering your home which means that your home can’t receive any warm air.

If you can hear the fan running then most likely your blower motor is in good condition.

On some newer units, there will be a light blinking if the blower motor isn’t working.

📍 Recommended reading: 9 Cheapest Ways To Heat Your Home This Winter

6. The burner has locked out

An oil burner has a primary control with a red reset button. If the flame fails to light, the control locks out and the button pops.

Press and hold the reset button once, for about a second. If the burner locks out again, stop there and call a technician: every failed start sprays more unburned oil into the combustion chamber, and a solid red light on a Beckett control means it has already locked out three times (Beckett troubleshooting guides).

7. Dirty flame sensor or clogged nozzle

An oil furnace has no pilot light. If you have a gas furnace with a standing pilot, see how to light a furnace pilot light. It uses a cad cell flame sensor and a fine spray nozzle, and soot on the sensor or a clogged nozzle or oil filter will stop the burner.

These are jobs for the annual service rather than a quick fix: switch the furnace off at its service switch before you open anything, and leave the burner itself to a technician.

Maintenance Tips

Here are some great tips that I’m personally using to keep the furnace working properly.

• Turn it on before it gets too cold because freezing temperatures can have a negative impact on the furnace if it isn’t heated up
• Clean filters every 3 months or even better – replace them.
• Try to recognize when the fan’s working sound is different
• Have a professional inspect your unit every 6 months.

If you need backup heat while you wait for a technician, check out the most energy efficient space heaters.