Proper water hardening operations are essential to maintain the boiler operating properly. Each water hardening operation must be specifically planned and designed based on the minerals not dissolved in the compensating water, the percentage of distillation return, and the percentage of aeration. Insoluble solids in boiler water and water hardness in small and low-pressure motorhomes should be tested daily and in large and high-pressure motorhomes on an hourly basis. An annual inspection of boilers should include a thorough inspection and testing for signs of fouling or corrosion on surfaces adjacent to the water. The presence of even a thin layer of sediment prevents heat transfer and thereby reduces combustion efficiency. .

The hot water produced by the boiler is pumped through pipes and reaches the building equipment, which can include hot water coils in the fan coils, hot water heating equipment and heating systems. Boilers produce steam that flows from high-pressure to low-pressure areas through pipes without the need for an external energy source, such as a pump. The steam used for heating can be used directly for steam-powered equipment, or through a heat exchanger can generate heat to produce hot water for the equipment.

Electric boilers are used in buildings that require very little steam or no access to natural gas. Electric boilers are referred to as clean, quiet, compact, and easy to install boilers. The lack of a combustion process reduces the complexity of design, execution, and maintenance. Heating agents can be easily replaced in case of failure. This type of engine room boiler can be used to generate steam or low pressure or high-pressure water or it can be a good option for those consumers who are limited by gas emission laws. Their size varies from , to , BTU input. In general, its efficiency is % to %.

Cast iron boilers are very useful because they can be collected in the basement and passed through smaller doors and gates. The most important drawback is that they are prone to leakage due to the connection of the parts by the washer when the washer becomes old or damaged by chemical reactions. Among the famous cast iron boilers in Iran, we can mention the boiler cast iron boiler and M.I. cast iron boiler made by Iran Pipe and Machine Building Company.

Engine room boilers have capabilities that have made them the main and common part of buildings. Boilers have a long life, and boiler efficiencies can achieve efficiencies of % and above, provide effective methods for heating buildings, and require very little or zero pumping energy in steam systems. But fuel can be significant, and regular maintenance is required by the facility engineer, and if it is delayed, the cost of repairing the engine room can be high.