Pay special attention to the filters of your oil furnace. They should be changed regularly; it's very important for home energy improvements.
See the owner’s manual for details on how to change the air and fuel-oil filters. It's a typical DIY job.
But there are less easy maintenance tasks – involving the cleaning of the burner and the heat exchanger, and several other checks, tests and cleaning tasks -, that should be carried out by a professional.
Even technicians may not be knowledge enough, and you should try hard to hire a capable one. That’s important for energy savings and safety.
Low airflow in a furnace can cause short cycling and is a cause of under-performance and low efficiency. It can be caused by clogged filters or by dirty fan blades, dirty coils, low-fan speed, loose fan drive belts or undersized ducts.
Oil furnaces are more demanding than gas furnaces; they do not burn as cleanly, and require professional maintenance of the blower, electrodes, controls, etc.
Check for possible leaks at the fuel storage tank. Look for dripping or signs of oil. Leaks should be fixed immediately. Call the technician.
Furnace maintenance if very important for safety. Furnaces emit dangerous pollutants, and you should have a CO detector in each level of the house (less than $30): see Amazon CO Detectors, for prices and customer reviews.
Odd noises on your oil furnace should be inspected. They may be caused by problems in the burner (a reason for calling a heating professional) or by a loose access panel or damaged belts (in the blower).
Lubrication and Wiring
Pay attention to the motor parts. Lubricate them at the beginning and middle of the heating season. Remove any possible dust and dirt. Use proper lubrication oil. Inspect oil leaks and smudges on the burner mounting plate. Take into account the owner's manual.
Oil furnaces should be professionally maintained every year. They are like cars. They need regular maintenance. Poor maintenance will cost you many hundreds or thousands of dollars during its lifetime.
Inspect the visible wiring and other electrical connections for cracked elements, burns and loose wire nuts and tape. In case of smudges on the burner mounting plates or blackened areas involving the electrical components, call a professional.
Smoke, chimney and exhaust stack
Inspect the smoke in the chimney stack. Black smoke is a sign that the furnace is not tuned up. Also inspect the exhaust stack. Look for leaks and holes.
Look for rust or gaps in the vent connections and chimney. The parts of the venting system can deteriorate over time.
Call a technician, if it is the case. Leaks are dangerous and pollutant.
Inspect the thermostat and the stack control as well as the blower, and clean them. The blower and the stack control should be cleaned and checked at least twice throughout the season.
There are some simple problems that DIYselfers can fix: maladjustments in the thermostat, lack of oil in the tank, clogged air and oil filters and blower. But be sure that you know what you are doing.