FAQs on boilers
What type of fuel do oil boilers use?
Generally in the UK domestic oil fired boilers use Kerosene, which is the same as aircraft fuel. It’s clean burning with low CO2 emissions. It’s rare that an appliance uses Diesel instead of Kerosene. If in doubt check your instruction manual which should confirm which one.
Are oil fired boilers safe?
If your boiler and the flue system are installed to comply with current regulatory and manufacturers’ requirements and the installation is regularly serviced and maintained, you can expect many years of safe operation. As an additional safeguard, a remote sensing fire valve must be fitted in the oil supply line immediately outside the property. This will automatically cut off the fuel supply into your house and to your boiler in the event of a fire. If in doubt, ask your OFTEC Registered Technician to check this for you.
How efficient is my boiler?
Modern oil fired boilers are extremely efficient – more so than some of their gas counterparts. Manufacturers quote efficiency levels in their sales literature, and you can also find details on the OFTEC equipment directory. Although oil boilers are extremely robust and long lasting, if your boiler is over 20 years old it might not be very efficient, so it’s worth considering a replacement model.
OFTEC coordinates an OFCERT® licence scheme, where manufacturers can have their equipment tested to an OFTEC Standard. Look out for the OFCERT® logo or licence number when discussing equipment with your installer or service technician. Home owners can ask for a FREE A-G energy rating for their boiler with advice to help cut fuel bills, when the engineer visits. Technicians can download the Domestic Oil Efficiency Checklist from here.
What are condensing appliances?
When a boiler operates, it turns energy from the boiler into hot water. A percentage of this energy is lost up the chimney or through the flue – the flue will get hot and this is a small % of the energy escaping this way. A condensing boiler captures an amount of this extra energy, adding it to the total heat produced. A condensing or high efficiency boiler produces more energy than a standard efficiency one, and will cost less to run. Depending on the installation, different Building Regulations may apply
What does the output level mean?
Output can be quoted in either Btu (British Thermal Units) or KW (Kilowatts)units. The size of boiler you need will depend on several factors including the total size of your house, radiators, window and door openings, wall type etc. Your OFTEC Registered Technicians will be able to advise on the appropriate size for your needs.
My boiler has been installed, but now it needs commissioning. What does that mean?
Simply connecting a boiler up doesn’t mean that it will work most efficiently for you. Commissioning is the fine tuning to make sure the boiler and burner are set up properly for the individual installation – and no two are alike! Your OFTEC Registered Technician will make sure the appliance is commissioned correctly by doing things like analysing the flue gases, and flow and return temperatures to make sure the system is operating at optimal efficiency and the lowest running costs.
A written record of the work that has been undertaken and the commissioning combustion figurers will be recorded and a copy left with you.
I am having a replacement boiler installed and my OFTEC Registered Technician has advised that my chimney will need re-lining. The chimney was re-lined six years ago, will the lining need to be replaced?
Yes, when installing a new/replacement appliance the chimney will need to be re-lined with a stainless steel flue liner, the OFTEC Registered Technician is required to ensure as far as is reasonably practicable that the liner should last the life of the appliance.
If a new/replacement is reconnected to existing stainless steel flue liner, the existing stainless steel flue liner may spilt (allowing products of combustion to escape) when it is disturbed without the technician knowing it.
How often should I get my boiler serviced?
It’s important to have any oil fired appliance such as a boiler, stove or cooker serviced once a year. The flue will need checking to make sure it’s clear, and your OFTEC Registered Technician can also check to see the boiler is running safely and efficiently for you.
You should always check with the manufacturer for service schedules as some boilers may require servicing more often than others.
Is it possible to obtain insurance for an oil fired boiler and central heating system in the same way as for a gas system?
Yes, there should be no problem. Some service and maintenance companies offer their own varying types and levels of cover, and some are agents for specific companies and policies. Ask your local OFTEC Registered Service and Commissioning Technician/Company for details.
Further help
We also produce a series of FREE downloadable Easy Guides. You may find one of these is helpful.
If you can’t find the answers you are looking for here you can contact the OFTEC Technical Helpline on 0905 757 0135 (calls are charged at 95p a minute, but some service providers may vary) and speak to a member of the OFTEC Technical Team.
Alternatively, you can send in a technical enquiry form. We aim to respond to technical enquiry e-mails within 3 working days.