What does an oil boiler service include

What Does an Oil Boiler Service Include?

If your home is heated by an oil-fired boiler, regular servicing is one of the most important investments you can make. An annual oil boiler service not only helps keep your heating system operating safely and efficiently but can also reduce fuel consumption, prevent costly breakdowns and extend the lifespan of your boiler.

Unlike gas boilers, oil-fired heating systems require regular cleaning because the combustion process naturally produces soot and deposits that can affect efficiency over time. Without routine maintenance, these deposits build up inside the boiler and burner, causing the appliance to work harder, burn more fuel and potentially develop expensive faults.

In this article, we’ll explain exactly what happens during a professional oil boiler service, why it matters and how to choose an experienced oil heating specialist.

Why Should You Service an Oil Boiler Every Year?

Your oil boiler works hard throughout the colder months, often operating for several hours every day. During this time, components naturally wear, combustion deposits accumulate and moving parts gradually deteriorate.

A professional annual service ensures your heating system continues to operate safely and efficiently while allowing worn components to be identified before they fail.

Regular servicing helps to:

Improve boiler efficiency
Reduce heating oil consumption
Lower fuel bills
Prevent unexpected breakdowns
Extend boiler lifespan
Improve reliability
Maintain safe operation
Identify developing faults early

Considering the cost of heating oil, even a small improvement in efficiency can produce noticeable savings over the course of a year.

What Happens During an Oil Boiler Service?

Although every boiler manufacturer has slightly different servicing procedures, a comprehensive oil boiler service generally follows a structured process covering the boiler, burner, fuel supply and heating controls.

A reputable engineer won’t simply “look over” the appliance they’ll carry out a detailed inspection, clean critical components, perform combustion testing and confirm the boiler is operating safely and efficiently.

1. Initial Visual Inspection

Every service begins with a careful inspection of the entire heating system.

Your engineer will check:

Overall boiler condition
Pipework
Oil supply
Boiler casing
Signs of corrosion
Water leaks
Oil leaks
Ventilation
Flue condition

This initial inspection often highlights issues that may require further investigation.

2. Inspecting the Oil Tank and Fuel Supply

A reliable fuel supply is essential for efficient boiler operation.

During the service, the engineer will inspect:

Oil supply pipework
Isolation valves
Oil filters
Flexible fuel lines
Signs of contamination
Evidence of leaks
General tank condition (where accessible)

Any signs of deterioration or contamination can be identified before they begin affecting the boiler.

3. Cleaning the Oil Burner

One of the most important parts of the service is cleaning the oil burner.

Over time, combustion creates soot and carbon deposits that reduce burner efficiency.

Your engineer will clean:

Burner components
Combustion head
Air intake
Burner housing
Ignition area

A clean burner produces a cleaner, more efficient flame.

4. Inspecting the Oil Nozzle

The oil nozzle is responsible for atomising the heating oil into a fine spray.

Even slight wear can affect combustion efficiency.

During the service, the engineer will:

Inspect the nozzle
Check spray pattern
Replace the nozzle where recommended
Confirm correct specification

This relatively inexpensive component plays a major role in overall boiler performance.

5. Replacing or Cleaning the Oil Filter

The oil filter prevents contaminants reaching the burner.

A blocked or dirty filter can cause:

Poor combustion
Difficult starting
Boiler lockouts
Reduced efficiency

Many engineers replace the oil filter during the annual service as part of routine maintenance.

6. Cleaning the Heat Exchanger

The heat exchanger transfers heat from the burner into your heating water.

Soot gradually builds up on its surfaces, reducing heat transfer efficiency.

Cleaning the heat exchanger helps:

Improve efficiency
Reduce fuel usage
Increase heat output
Lower operating costs

Even a thin layer of soot can noticeably reduce performance.

7. Flue Inspection

The flue safely removes combustion gases from your property.

During servicing the engineer checks:

Flue integrity
Flue joints
Signs of corrosion
Blockages
Correct termination
Safe operation

A damaged flue can affect combustion and boiler performance.

8. Combustion Analysis

One of the most valuable parts of a professional service is combustion testing.

Using specialist electronic equipment, the engineer measures how efficiently the boiler is burning heating oil.

The analyser measures factors including:

Combustion efficiency
Oxygen levels
Carbon dioxide
Flue gas temperature
Smoke levels

The burner can then be adjusted to achieve optimum performance.

This is something that cannot be assessed by visual inspection alone.

9. Safety Device Testing

Modern oil boilers contain numerous safety controls designed to protect both the appliance and your home.

These include:

Boiler thermostat
High-limit thermostat
Burner controls
Safety lockouts
Pump operation
Pressure controls

Every safety system should be checked during servicing.

10. Heating System Inspection

Your engineer will also inspect the wider heating system.

This may include checking:

System pressure
Circulating pump
Expansion vessel
Radiators
Heating controls
Programmer
Thermostats

Problems elsewhere within the heating system can affect overall boiler performance.

11. Operational Testing

Before leaving, the engineer will restart the boiler and confirm everything is operating correctly.

This includes checking:

Burner ignition
Flame stability
Water temperature
Heating operation
Hot water production
Control operation
Shutdown sequence

Only once everything is operating correctly should the service be considered complete.

How Long Does an Oil Boiler Service Take?

A thorough service typically takes between 60 and 90 minutes, depending on:

Boiler age
Boiler condition
Manufacturer
Accessibility
Whether additional maintenance is required

If an engineer is finished in only 15 or 20 minutes, it’s worth asking exactly what checks have been carried out.

Why Efficiency Matters

Heating oil represents a significant household expense, particularly during the winter months.

A poorly maintained boiler may continue working, but it could be burning considerably more fuel than necessary.

Regular servicing helps maintain:

Efficient combustion
Correct burner settings
Clean heat transfer
Reliable fuel delivery
Maximum heat output

All of which contribute to lower running costs.

Choosing a Reputable Oil Boiler Specialist

Not every heating engineer regularly works on oil-fired systems.

Oil boilers require specialist knowledge, dedicated combustion testing equipment and an understanding of oil burner adjustment.

When choosing a company, look for one that:

Regularly services oil boilers
Has experience with your boiler manufacturer
Uses electronic combustion analysers
Carries out full burner servicing
Provides honest recommendations
Explains any faults clearly
Has strong local reviews and recommendations
Offers ongoing servicing and maintenance

A reputable engineer will never rush a service or recommend unnecessary replacement parts.

Instead, they will explain the condition of your boiler, identify any developing issues and help you make informed decisions about future maintenance.

Can Regular Servicing Extend Boiler Life?

Absolutely.

Many oil boilers continue operating reliably for 15–20 years or more when properly maintained.

Routine servicing reduces unnecessary wear, keeps components clean and allows minor faults to be repaired before they develop into major failures.

Considering the cost of replacing an oil boiler, annual servicing represents excellent value for money.

A comprehensive inspection, cleaning and optimisation process

A professional oil boiler service is about far more than simply checking that your heating is working. It is a comprehensive inspection, cleaning and optimisation process that keeps your boiler operating safely, efficiently and reliably throughout the year.

From cleaning the burner and heat exchanger to replacing filters, testing combustion performance and inspecting critical safety devices, every stage of the service contributes to improved efficiency, reduced fuel consumption and greater peace of mind.

By choosing an experienced oil boiler specialist, you’ll not only protect your heating system but also maximise its lifespan and keep your home warm through every season.

If your annual oil boiler service is due, Mark Abraham Gas provides professional oil boiler servicing throughout Peterborough and the surrounding areas. Our experienced engineers carry out comprehensive servicing to manufacturer recommendations, helping you get the very best performance from your oil heating system year after year.

WHY CHOOSE US

Why Customer Choose Mark Abraham

At Mark Abraham Gas, we are a local family business with over 30 years of experience. We have built an excellent and positive reputation through our honest advice, quality workmanship and exceptional customer service. Our company has access to quality replacement parts to install and service boilers from leading manufacturers, such as Worcester Bosch and Valliant etc.

Our outstanding and fully qualified engineers (Gas Safe Registered) have received a tremendous amount of exceptional reviews.

    
 
 
         
   Andy Newton 
 
 
 
 Trustindex verifies that the original source of the review is Google. About a week ago, 2 young engineers turned up on time and instantly made a great impression. Great attitude, professional, well-mannered, and a fantastic approach to work. Much better than mine was at their age!
The installation was flawless from start to finish. I honestly can't fault it, and I am deffo one of those picky annoying pricks who can find fault in anything. Mostly...
Whoever trained Kieran did an amazing job. Both Kieran and Leo should be proud of themselves for outstanding workmanship.
They played a blinder. Well done boys!
  
 
        
   Carol Weld 
 
 
 
 Trustindex verifies that the original source of the review is Google. Mark Abraham gas services originally installed my new boiler   They have always serviced every year and I have never had any problems with boiler
On Tuesday 2/6  their engineer called Charlie came to complete yearly service.  What a great guy. Friendly explained the service and answered my questions. Very clean tidy work and paperwork completed.
Charlie must be a credit to your company as great customer service   Very impressed as always over the years.
Thank you. Carol Weld
  
 
        
   Tracey Burton 
 
 
 
 Trustindex verifies that the original source of the review is Google. Great customer service from start to finish with my boiler replacement. The quotes provided for different models were clear and detailed. Lisa in the office found a very quick slot for the appointment and kept me up to date with timings etc. Boiler replacement was done in less than a day. I hardly knew Kieran was in my home other than the occasional drilling. My kitchen was spotless when he left, and he also made sure he had covered the Hive app and thermostat instructions before he went. Highly professional service from all colleagues at Mark Abraham.
  
 
        
   Jackie Pell 
 
 
 
 Trustindex verifies that the original source of the review is Google. Seamless annual check of old boiler and boiler replacement, both completed with a week.
Polite and professional staff from start to finish. Thankyou, Abraham’s
  
 
        
   linda marks 
 
 
 
 Trustindex verifies that the original source of the review is Google. I have used Mark Abraham Gas Services for about 15 years. They have replaced boilers in my pub, my house, my partner's house and my mother in law's house. They have continually serviced them each year. Very efficient service, lovely friendly engineers and trusted, genuine prices. I would fully recommend them to anyone.
  
 
        
   J H 
 
 
 
 Trustindex verifies that the original source of the review is Google. I loved my warm air heating but,  at 34 years old,  it had to go.  Mark came to my home and explained my options. I had the quote later that day and the appointment was made for the following week.  The work was completed in three days.

Everyone was absolutely brilliant. I was nervous of changing the heating and had been putting it off for years.  I can't tell you how relieved I am that it's now done.  As you'll see from other reviews,  everyone is professional but friendly.  No messing about, but very approachable, and nothing is too much trouble. They would let me know what they were doing, and come and talk to me if they came across any issues.  A solution was run past me to make sure I was happy before they went ahead. The engineers who worked so hard were Callum, Bradley and Leo.

There's just one little thing to sort out, but I'm sure that will be dealt with in the same way as everything else, so I'm not in the least bit worried.

Thank you ever so much. It's very rare to find tradespeople with such a culture, and you're all amazing. I'd recommend Mark Abraham Gas Services in a heartbeat!

Update 24th April: Just to say that my absolute confidence was not misplaced. All sorted. 😊
  
 
        
   Geoff Rudd 
 
 
 
 Trustindex verifies that the original source of the review is Google. Great experience from beginning to end. From the first visit from Mark to discuss the options for our new boiler and radiators, to the last day of installation with his team, the service was first class. High quality work to go with the right heating system for our needs. Faultless and professional at all times. I would highly recommend giving them a call.
  
 
        
   Lee Martin 
 
 
 
 Trustindex verifies that the original source of the review is Google. I cant  recommend Mark and his team highly enough for their freindly services and professionalism. From initial contact to completing the job was fast, no fuss and very reasonably priced. Thank you.
  
 
        
   Ian Coleman 
 
 
 
 Trustindex verifies that the original source of the review is Google. Used Mark Abraham to install a new boiler for us. All staff were very polite, respectful and professional. I would not hesitate to recommend to anyone. Engineer Stefan was very thorough and friendly. Well done Mark Abraham Gas Services for a 5 star job completed.
  
 
        
   Julia Thorpe 
 
 
 
 Trustindex verifies that the original source of the review is Google. Mark and his staff always provide a prompt, polite and professional service. Prices are fair and competitive. Lisa, in the office, is very helpful and friendly. Customers are treated respectfully and regulars are acknowledged.