Is it REALLY necessary to service your Oil Boiler EVERY Year???

Well unfortunately yes it is. Most internet resources will tell you all about efficiency, the environment, etc, etc, etc... But the main reason Oil Boilers need servicing every year is simply because they are dirty, smelly things - Honestly, I can look like a chimney sweep by the end of the day!! Even when set up and running at their most efficient, a small amount of the minerals contained within the oil get left behind when the oil is burnt. These slowly build up, and just like limescale in your kettle, once a thin layer has formed it makes a perfect surface for more to accumulate on.

So the short answer is "Yes" because your boiler will eventually clog up and stop working. Breakdowns will become more frequent and the boiler will not last as long (and for those of you who have not had to replace an oil boiler yet, be warned - they are a hell of a lot more expensive to buy and install than gas boilers).

Effects of not servicing on the Burner

The nozzle pictured on the left is from a boiler that was not serviced for about two and a half years. Kerosene is fairly abrasive (for an oil) and as it's pumped through the minute hole in the end of the nozzle at around 120psi it continually wears the hole, eventually causing a little more oil than is ideal to pass through. As the amount of air that the burners fan blows in remains unchanged the fuel/air mixture becomes 'rich' - for those of you that remember cars with carburetors, very similar to your car running rich, which as you know, eventually coked up the engine. As you can see in the photo, the two ignition electrodes (the sparkplug if you like) have heavy deposits on them and it is very likely that in the very near future would have been unable to create a spark and the boiler would stop working.

Another common issue that occurs because of the burner running rich is the Photocell (a light sensing safety component) starts to soot over. The main job of the photocell is to look for light in the boiler, keeping a check that a flame is maintained when it should be and shutting down the burner immediately should the flame go out. If it gets covered in soot it cannot see that a flame has been established upon ignition and will tell the control box (the brains of the operation) to lock out the burner and the boiler will not work.

Effects of not servicing on the Boiler

Other than a burner, oil boilers are essentially a combustion chamber (into which the burner fires a flame) surrounded by a water-jacket which contains your central heating water. Inside the combustion chamber are a series of baffles (pictured left) and their job is to delay the hot gases from going up and out the flue too quickly. Whilst the hot gases are kept within the combustion chamber, heat is being transferred into the central heating water (flowing round the water-jacket) to be pumped around your radiators and heat your hot water.

As the boiler builds up a sooty layer on the walls of the combustion chamber over time, this will prevent heat transfer into the water (soot is a good heat insulator by the way) so your boiler will be less efficient and will have to run for longer (burning more oil) to get the same amount of heat into the radiators and hot water cylinder. So it is essential that your boilers combustion chamber is cleaned out every year.

If mineral deposits build up on the baffles to an excessive degree, airflow is slowed down too much, causing the boiler to overheat and eventually causing damage to the baffles, the burner and eventually the boiler itself. So again it is essential that your boilers baffles are cleaned every year to prevent this build up.

The following photos show the same boiler before and after its annual service. You can see how the muck has built up over the year and note that despite vigorous cleaning it is impossible to get all the deposits off, demonstrating why an annual service is essential to the longevity of your oil boiler.

For any questions you might have about your oil boiler please feel free to give me a call

on 01279 651900. I offer a Fixed Price Service inclusive of service parts. Click here for info.