Why Your Oil Furnace Won’t Turn On (QUICK FIX)

Dominic Mitton
By Dominic  • Reviewed by Ben  • Updated:   October 26, 2023
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If your oil furnace won’t turn on suddenly, there’s no room to panic.

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 can send wrong signals and it’s set to cool instead of heat.

The best practice here is to set the thermostat to 15 degrees warmer 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.

You should change filters every 30 days 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. Full pan

Sometimes the float switch turns the HVAC unit off because it recognizes that the pan is full of water.

To prevent this from happening, you should pour half a cup of vinegar down the condensation line every 90 days or so.

If the pan is full of water, make sure to empty the water and even use a vacuum to remove all water from the condensation line.

7. Pilot flame is dirty

Pilot flame should be cleaned because it has a flame sensor around it which needs to be dust-free to work properly.

A lot of people overlook this, but I would highly suggest cleaning the pilot flame as well and not just the filters.

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 don’t want to spend time and energy on maintaining your heating system, you should check out most energy efficient space heaters.

Hey there! I am Benas, the founder and content editor at Home Caprice. Thanks for reading the article. I hope you were able to find what you were looking for. I and my team are here to simplify heating and cooling for everyone. Please have a look at the About page for more details about our website and feel free to check out our editorial process.