Boiler Repairs - One-Off Repair or Repair & Cover

Oil Fired Boilers

With the increase in properties being built in rural locations more homes are remote from the gas mains and an oil fired boiler is a viable home heating alternative. Recently oil fuel prices have been very high, as have gas prices, although for most of the past ten years it has been significantly cheaper to run than bulk LPG or bottled gas and, in many circumstances, cheaper than electricity or anthracite.

If you are buying a home that has oil central heating, or if you are looking to install or upgrade an oil-fired boiler system you should consider the facts detailed below.

What are the components of an oil central heating system?

An oil-fired central heating system will have the same heating controls as a modern gas-fired system. You should ensure that it has:

  • an adjustable room thermostat, ideally located in a well used living room, not the hallway or little used room
  • thermostatic radiator valves (TRVs) on the radiators to allow you to have control over room temperatures
  • an electronic 7 day timer with separately programmable hot water and room heating programs
  • a cylinder thermostat on the hot water tank to control the water temperature
  • the boiler and thermostats wired in an interlock to prevent short-cycling when there is no demand for either hot water or room heating

What type of oil fired boilers are there?

Once again the development of oil-fired boilers has shadowed the development of gas-fired boilers and there are many similarities.

Oil fired Condensing Boilers: From 1st April 2007, it has been mandatory to install condensing oil boilers to comply with the latest Building Regulations. More manufacturers are adding oil condensing boilers to their ranges all the time.

Combi or Combination Boilers: Oil-fired combination boilers are available, providing hot water on demand without the need for a hot water tank, saving space. However, it should be noted that they are often slower to provide hot water than some gas combi boilers, and that they are not always recommended for larger households. This is addressed through a combi boiler holding a reserve of hot water within the casing although this reduces the energy efficiency performance of the boiler.

Oil boilers are available with both balanced flues (where the air for combustion is drawn in through a pipe concentric with the extract flue) and with open flues, where the air for combustion is drawn from the room in which the boiler is sited. Although Building Regulations permit both types of a boiler to be located in domestic garages, experts recommend that only balanced flue boilers are used in those areas.

Are Oil Fired boilers as efficient as gas boilers?

Similar to gas fired boilers modern oil-fired boilers can be very efficient and manufacturers list operating efficiencies of up to 97%. As with gas boilers, condensing boilers are likely to offer the greatest efficiency due to capturing the heat from the exhaust gases, and there are now many Sedbuk “A” rated models on the market.

What type of oil should I use with an oil-fired boiler?

Almost all UK domestic central heating systems use 28sec oil, which is sometimes known as kerosene. This fuel burns more cleanly than heavier oil products such as gasoil, which is also known as 35sec heating oil, producing cleaner exhaust gases.
As the sulphur content of oil has fallen, some domestic oil suppliers have added additional lubricants to kerosene to enable fuel to be pumped to the boiler more easily. Older pumping systems could struggle to pump oil over a distance or in cold conditions. This is not usually necessary for newer systems, as modern pumps have been engineered to operate effectively with low-sulphur fuels.

Is oil less friendly to the environment?

A modern high-efficiency oil system can provide an environmentally acceptable alternative heating system, especially for homes that are not connected to the gas main. As with all heating systems, regular servicing and maintenance will help the boiler burn more cleanly and efficiently.

Official figures from the UK’s Department for the Environment, Farming and Rural Affairs (Defra) indicate a carbon content for domestic heating oil (kerosene) of 0.24kgCO2 per kWh, compared to figures of 0.214kgCO2 per kWh for LPG and 0.19kgCO2 per kWh for gas.

If you are particularly keen to minimise carbon emissions, you could also consider supplementing an oil central heating system with a modern wood-burning or pellet stove, using sustainable wood fuel. Another alternative is to consider using Solar Water Heating panels, that should be able to provide up to half your homes hot water requirements.

Are there special installation requirements for an oil fired heating system?

Although there is no legal requirement for oil boilers to be installed by a specially trained person, it is recommended that all servicing and installations are carried out by people registered with Oftec, the Oil-Fired Technical Association.