There are many types of boilers, which are divided into gas steam boilers, oil steam boilers, electric boilers, biomass boilers, etc. according to the type of fuel. Among them, gas steam boilers and oil steam boilers are the two most common choices. This article will focus on the difference between the gas steam boiler and oil steam boiler and provide you with a reference in the process of choosing a boiler. If you have any questions, you can contact us and we will give you a detailed answer.

Main Difference

The main difference between gas steam boilers and oil steam boilers is the different fuels used. The main fuels of gas steam boilers are natural gas, biogas, liquefied gas, etc., and the main fuels of oil steam boilers are diesel, heavy oil, etc.

Working Principle

The principle of gas steam boilers is that the heat released by the combustion of natural gas and other fuels in the furnace heats the water in the pot and vaporizes it into steam. The water in the pot is continuously heated by the energy released by the combustion of gas fuel in the furnace, the temperature rises and pressurized steam is generated.

The working principle of the oil steam boiler is to spray the fuel into the burner combustion chamber under the control of the fuel supply system, and ignite it in the combustion chamber to form a flame. At the same time, the water inside the boiler enters the water circulation system of the boiler through the delivery pump under the control of the boiler system. After heating, the water becomes saturated water vapor or superheated water vapor. After that, the water vapor passes through the grate and superheater and enters the steam pipe to provide heat to the equipment and systems that need it.

Gas fired steam boiler

Working Efficiency

Gas steam boiler

Gas steam boilers are generally more efficient than oil steam boilers. The combustion process of natural gas is cleaner and more complete, resulting in higher thermal efficiency. Modern gas steam boilers can reach efficiencies of more than 90%, and some high-efficiency models can even reach efficiencies of up to 98%. This higher efficiency means lower fuel consumption and lower operating costs over time.

Oil steam boiler

Oil steam boilers are generally less efficient than gas steam boilers. The combustion process of oil is less complete, resulting in lower thermal efficiency. The efficiency of standard oil steam boilers is generally between 80-85%. Although there are also high-efficiency oil steam boilers, they are less common and more expensive.

Boiler Lifespan

Gas steam boilers generally have a longer service life than oil steam boilers, with a gas steam boiler service life of about 20 years and an oil steam boiler service life of between 10-15 years.

Diesel fired steam boiler

Advantages and Disadvantages

Advantages of Gas Steam Boilers

  1. Gas steam boilers are more environmentally friendly. When gas is burned, its main components are carbon dioxide and water vapor, and almost no other harmful exhaust gas is produced. The extensive use of gas steam boilers can reduce air pollution and protect the environment.
  2. Gas steam boilers have higher thermal efficiency and lower heat energy loss during combustion. Generally speaking, compared with oil steam boilers, gas steam boilers have higher energy efficiency ratios, are more energy-saving and economical to use.
  3. Gas steam boilers are easy to use. Gas steam boilers do not need to store fuel oil, so they are easy to use. You only need to connect the pipeline to the gas to use it. In addition, gas steam boilers do not need to be cleaned regularly, have a longer service life, and are more convenient.

Disadvantages of Gas Steam Boilers

  1. Dependence on natural gas supply: The operation of gas steam boilers depends on a stable supply of natural gas, and fluctuations in natural gas prices may directly affect operating costs.
  2. Restricted by gas sources: In some areas, the natural gas source may be insufficient, which may limit the use of gas steam boilers.
  3. High maintenance costs: Gas steam boilers have a low failure rate, but if they encounter a failure, the maintenance cost is also relatively high.

Advantages of Oil Steam Boilers

  1. Oil is widely distributed and suitable for some areas with limited natural gas supply
  2. Oil steam boilers can withstand adverse weather conditions
  3. Wide range of applications, oil steam boilers are suitable for heating systems of various buildings, whether residential, commercial buildings or industrial plants, can play a good heating effect.

natural gas steam boiler

Disadvantages of Oil Steam Boilers

  1. The degree of environmental protection and cleanliness is not high enough, and there is a possibility of black smoke after long-term use, which is relatively clean compared to gas steam boilers
  2. The energy utilization efficiency of oil steam boilers is low, which means that a lot of energy will be wasted during use, resulting in high energy costs.
  3. Oil steam boilers need to be cleaned and maintained regularly to ensure their efficient operation.

Maintenance and Operation

Gas steam boilers are generally easier to maintain and less expensive. The combustion process of natural gas is cleaner, and less soot and residue accumulates in the boiler. This reduces the frequency and intensity of cleaning and maintenance tasks. In addition, natural gas steam boilers usually have fewer mechanical parts, making them more reliable and easier to repair.

Oil steam boilers require more frequent maintenance due to the residue and soot produced during the combustion process. Regular cleaning of the burner, heat exchanger, and flue is necessary to maintain efficiency and prevent operational problems. Oil steam boilers also have more mechanical parts, such as fuel pumps and filters, which may require more frequent repairs and replacements.

diesel boiler service

Price of Gas Steam Boilers and Oil Steam Boilers

Depending on the amount of boiler evaporation, the price is also different. The price of gas steam boilers is between $3,500.00 – $18,000.00, and the price of oil steam boilers is between $2,500.00 – $18,000.00.

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Local Policies

Gas steam boilers are generally subject to fewer regulatory restrictions than oil steam boilers due to the cleaner combustion process. Gas steam boilers generally have less stringent emission standards, making it easier to comply with environmental regulations. This can reduce the administrative burden and costs associated with permits and compliance.

Oil steam boilers are subject to stricter emission standards due to the higher levels of pollutants produced by oil steam boilers. Complying with these regulations can be costly and complex, requiring additional equipment and controls to reduce emissions. The regulatory environment for oil steam boilers varies from region to region, affecting the feasibility and cost of using oil as a fuel source.

How to Choose

When choosing between gas steam boilers and oil steam boilers, you should choose according to actual conditions. If the gas supply conditions in the area are good, gas steam boilers should be given priority; if the gas supply is limited or the gas supply conditions are not very good, oil steam boilers can be selected. At the same time, the use effect and scope of application of the boiler should also be considered, and a boiler that can meet your needs should be selected.


In short, natural gas steam boilers and oil steam boilers have their own advantages and disadvantages. Gas steam boilers are more efficient, safer and more environmentally friendly, but the initial investment is large and the gas supply is limited; oil steam boilers are stable in use and flexible in fuel supply. They are a practical choice in areas where natural gas cannot be used. When choosing, you should consider the actual situation comprehensively and choose a suitable boiler.

If you have questions about whether an gas or oil boiler would be better suited for you, you can contact us at any time: +0086 156-9085-0708!

About Dabonn

About Dabonn

Zhengzhou Dabonn Energy Co., Ltd.

We have more than 20 years of experience in boiler system equipment research and development and manufacturing. And committed to designing and producing boilers that suit your needs, including fire-tube, water-tube, and steam boilers, while also staying up-to-date with the latest technological boiler.

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