Q&A for How to Restart a Furnace After Running out of Oil

I've often run into this problem. Power it off at the breaker or power switch and turn it back on after one minute. Press reset - if no restart occurs, hold reset for up to 30 seconds. If that doesn't work, try turning up the thermostat, changing the in line oil filter, making sure there is enough water from the tank, and bleeding air from the water tank.

That it could be it. The filter could be clogging. The worst case is that the pumping mechanism is failing, though that's doubtful. Is it running smoothly? It should be regularly cleaned inside, and it wouldn't hurt to have it serviced.

Try a custom vacuum chamber with a controlled ratio of volume to mass inlet. In a secondary chamber, insulated from the initial point of entry, create an outlet for the altered atms of pressure.

You have air in the oil line. With a tiger loop it can usually be sorted with a few presses of the reset button; otherwise, it will need bleeding.

Use vise grips and plan on getting a new bleeder screw from the supply house.

It could take a couple tries 4 or 5 (depending on the length of the tubing). Loosen the bleeder enough.

Just tighten the bleeder when it stops then restart and continue. The oil will not go back into the tank if you tighten it within a couple seconds and will progress when you restart.

Usually, any time you run out of fuel, replace a filter, or expose the fuel line to air, the pump will need to be bled or primed. The amount of time/number of starts required to bleed the line completely depends a lot on the distance between the tank and the burner. A sputtering flame usually indicates there's still air in the line. If after a large number of priming sessions it is still sputtering or flaming out, the problem may be due to an insufficient volume of fuel due to a clogged filter or fuel line. Removing the filter to allow some sludge from the tank to escape will usually solve this, but if the lines are clogged, a blast of CO2 from the furnace to the tank may be required.

A soft lockout resets by itself. A hard lockout requires pressing the reset button for 2-3 seconds. A restricted lockout requires pressing the reset button for ~10 seconds. The entire time you are holding the reset button in, you are forcing the burner to pump oil into the furnace. Without ignition, it will not take very many times doing this to saturate the chamber. Once the chamber has been saturated, it must be replaced. A call to an oil burner tech to fix the problem will likely cost less than replacing the chamber yourself.

In most cases, it is located to the left of the pump and it looks like a grease fitting.

It depends on how long the burner is on. If it is not igniting, leave the boiler for an hour and see what happens.

The reset button is part of and located on the primary control, an electrically-operated device usually affixed to the oil burner assembly (oil pump, combustion fan, igniter, ignition transformer, flame detector). It will often have indicator lamp(s) to provide status via one or more colored lights or by flashing. This control has the reset button or switch on it.