Staying warm is dependent upon an operational furnace. That's why it's so frustrating when your oil furnace won't cycle on. The following are some common issues that may cause an oil furnace to fail.
The oil tank likely has a gauge on it that lets you easily see how much fuel you have left. Unfortunately, these gauges can fail and give a false reading. When this happens, you may run out of oil, and the furnace will shut down.
You can check the oil level without using the external gauge with the help of a dipstick, available at any hardware store. Open the check valve located on the tank, and insert the dipstick until it touches the bottom of the tank. You can then pull it out to see how much oil really remains. If the level is low, a refill and a replacement gauge may be all you need.
Fuel Line Issues
Two issues can affect fuel lines -- a blockage or air in the lines. Blockages typically occur when an oil tank is run nearly empty before fuel is added. The addition of fuel stirs up sludge in the tank, where it can then get lodged in a fuel line.
Air may also get in a line if the tank is run empty. You can tell the problem is air if there is a knocking sound when you try to run the furnace. A technician can clear the blockage or bleed the lines to remove air.
Oil furnaces don't use a traditional pilot light. Instead, they have an ignition that lights the fuel just as it hits the burner. The ignition system consists of the igniter and the fuel valve.
A failure to ignite may mean that either the fuel valve is clogged and needs to be cleaned or replaced. If the problem is the igniter, then it may need to be repaired or replaced.
An oil furnace typically has two filters. The air filter, which is common to all furnaces, pulls air into the furnace for circulation. If it becomes overly dirty and clogged, the furnace may fail to fire on or it may cycle rapidly.
The fuel filter is designed to catch sediments before they reach the burner. When this filter becomes clogged, no oil can get to the burner, so the furnace will not fire on. Replacement of the filters solves the issue.
Contact a company that provides heating services near you for more help.