Buying an oil-fired boiler: advice and prices

Are you considering having an oil-fired boiler installed in your home? Discover the advice of our experts and the budget you will need depending on the model chosen.

The oil boiler: what are its characteristics?

To operate, the oil boiler is equipped with a device that burns the oil (the fuel), which heats the water circulating in the pipes of the house. The boiler can only be used for heating, or can also produce domestic hot water, or DHW. In this case, it is called a mixed or dual service boiler.

The size of the oil-fired boiler – and of a boiler powered by any other energy – must be sized according to the volume that needs to be heated and according to the insulation of your home. Being more efficient than gas or electric models, the oil boiler is generally preferred for heating large homes.

The oil-fired boiler cannot operate without a storage tank, also sized according to the surface to be heated. Installed indoors or outdoors, it contains fuel oil and supplies the boiler.

How does an oil boiler work?

The oil-fired boiler heats the water using a burner that burns the fuel oil stored in the supply tank. This heated water is then circulated through the home’s hot water radiators or into the underfloor heating system to provide heat to the home.

There are two types of oil boilers: the low temperature model and the condensing model.

  • The low temperature oil boiler heats the water to 40°. Cheaper to buy, it is not economical to use to heat large volumes.
  • The oil condensing boiler heats the water to 90°. The efficiency is higher than that of a low temperature boiler and allows savings to be made by heating large dwellings. However, it is more expensive to purchase.

The different technologies of oil-fired boilers

There are two different oil-fired boiler technologies: open or atmospheric boilers and sealed boilers.

The closed boiler or sealed boiler

This type of forced-air boiler works by means of two circuits: one for the air supply, the other for the evacuation of the gases. As it does not require any flue or air call thanks to its airtight nature, its installation does not involve heavy work and it can be placed in a closed room without danger.

The open boiler or atmospheric boiler

This model of boiler needs a lined flue to take in outside air for combustion and to evacuate the gases. This non-watertight nature makes it impossible to install it in a closed room that does not benefit from sufficient and regular air renewal.

Hot water production

If the oil-fired boiler is dual service or mixed, in other words if it also produces domestic hot water, this can be instantaneous, storage or micro-storage.

  • Accumulation production: the boiler is fitted with a tank which collects a large reserve of water intended for immediate use. If this method is more economical, it is also more imposing and needs space. It is more suitable for large families (minimum 4 people) and homes with two or more bathrooms.
  • Micro-accumulation production: the principle is the same as for storage production, but the balloon is smaller. The volume of immediate hot water is therefore reduced, but it is sufficient for immediate use for a couple or a house equipped with a single bathroom.
  • Instant production: since hot water is heated instantaneously, this type of device is only suitable for very limited hot water needs, otherwise it will cost you a lot of money. As a result, homes for large families and/or homes with at least two bathrooms will not be advised of this type of installation.

How to choose the right oil boiler?

Why change your boiler?

A boiler over 15 years old will cost you more to use and maintain, although its lifespan can still be extended. Choosing a new, more efficient model can bring you more safety and comfort, but also allow you to make significant energy savings! In addition, within the framework of energy renovation, the State can help you financially for the payment of your purchase.

Of course, as with most household appliances, the more expensive the boiler is to buy, the more it uses reassuring, economical and easy-to-use technologies. A well-maintained boiler can represent a significant investment, but it will save you money in use.

However, be aware that any device must be serviced every year by a professional to remain efficient and have a longer lifespan, regardless of the energy used. In addition, annual maintenance avoids the risk of excessive pollution and monoxide poisoning.

How to choose your oil boiler?

Before you start, you should ask yourself about your needs in order to choose a model of oil boiler that corresponds to your use and the size of your home.

In terms of technology, small budgets and small homes will be able to make do with a classic low-temperature model. Small consumers will be assured of savings with this device which is less expensive to purchase and to use for low needs due to its reduced efficiency.

Families of at least four people and/or residing in a larger dwelling and/or equipped with more than one bathroom should opt for condensing technology. More expensive to buy, it quickly becomes more economical to use. Profitability is almost immediate (5 years maximum) and you can also benefit from the state tax credit for this type of purchase.

The question of opting or not for a mixed model can legitimately arise. The production of hot water by means of the oil-fired boiler is interesting, especially in winter when it will not cost you much. On the other hand, this solution requires you to operate your boiler all year round, because hot water is also necessary in summer. You will therefore need to supply it with fuel continuously and keep the device on permanent standby. However, it is possible to opt for an insulated tank powered by the boiler or by the electrical network to overcome this problem.

In any case, remember to properly size your oil-fired boiler to the real needs of your home and your family. Your investment should not be conditioned by the purchase price, because a poorly sized device will not save you money in use, quite the contrary! A boiler that is too small will indeed consume a lot of energy to meet your needs, while a boiler that is too large will strive to heat a large volume of water unnecessarily.

When purchasing, also consider the placement of your storage tank. This can be placed indoors or outdoors, and should be sized according to the needs of the household and the dwelling.

What budget should I plan for an oil-fired boiler?

On average, an oil boiler costs more than a gas or electric model. On the other hand, it is less expensive than a hybrid or wood-fired boiler. Count between 1,000 euros for a classic entry-level model (low temperature) and 10,000 euros for a top-of-the-range model covering the needs of a large family. For information, the cheapest condensing models have a budget of around 4,000 euros to 5,000 euros. Finally, count between 300 euros and 2,000 euros to purchase and install the oil tank.

The price of installing a boiler varies between 500 euros and 1,500 euros, depending on the type of technology chosen, the context of the installation (difficulty, work, access, etc.), the rates charged by the professional service provider and your region of residence. The cost of this type of installation is indeed higher than that of a gas or electric model.

Most families who opt for an oil-fired boiler make this choice because they do not benefit from a connection to the gas network. This technology is generally not appreciated because of its polluting nature and the sometimes high costs of fuel oil (which must also be restocked during the year). However, this technology is among the most efficient in terms of performance.

Finally, plan for at least 100 euros per year for annual maintenance costs. This must be done by a professional. Not only is this the only way to be in compliance in the event of a problem, but the service provider is also equipped with specific equipment and carries out the annual change of the parts necessary for the proper functioning of the device. Count up to 150 euros to 200 euros for a complete service requiring a little labor. This maintenance is however highly recommended, because a model that is not or poorly maintained will cost you much more to have it repaired or replaced.

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