If you’ve run out of heating oil and need to restart your oil boiler, follow the steps below to safely prime your system and get it running again. Here’s a step-by-step guide to help you prime an oil boiler and start it after running out of oil:

Note: If you’re uncomfortable with this process or unsure about any step, it’s strongly recommended to contact a professional heating technician for assistance.

  1. Check the Oil Tank:

Ensure that you have an adequate supply of heating oil in your tank before attempting to restart the boiler.

  1. Turn Off the Boiler:

If your boiler is running but has shut down due to low oil, turn off the power to the boiler to prevent it from cycling or attempting to ignite.

  1. Bleed the Oil Line:
  • Locate the oil pump or bleeder valve on the fuel pump. This valve is used to remove air from the fuel line and prime the system.
  • Place a container or absorbent material below the valve to catch any spilled oil.
  • Open the valve using a wrench or the appropriate tool. Slowly turn it counterclockwise until you hear air escaping and fuel starts to come out.
  1. Prime the Fuel Line:

If your system has a manual pump, pump it slowly to force fuel into the line and push out any remaining air. If it’s an automatic system, skip this step.

  1. Close the Valve:

Once you see a steady stream of fuel with no air bubbles, close the valve tightly.

  1. Turn On the Boiler:
  • Set your thermostat to a temperature higher than the current room temperature to trigger the boiler to start.
  • Turn the power back on to the boiler.
  1. Monitor the System:

As the boiler starts up, listen for any unusual noises and observe the flame if possible. If the system starts without issues, you’re on the right track.

  1. Observe the Flame:

If your boiler has a viewing window, check the flame color and quality. A steady blue flame indicates proper combustion.

  1. Check for Leaks:

After the boiler is running, inspect the fuel line, pump, and connections for any signs of leaks.

  1. Monitor System Operation:

Pay attention to the system’s operation for the next few hours. If you notice any irregularities or issues, contact a professional technician.

Remember that restarting an oil boiler after running out of oil requires care and attention to safety. If you’re not confident in your ability to perform these steps, it’s best to consult a licensed heating technician to ensure a safe and successful restart of your boiler system. We can help with prime-start – just give us a call and we’ll send one of our expert techs as soon as possible.