Over the past few years, the supply chain for many items has been extremely stressed. The supply of commercial cast iron boilers is no exception. Finding a readily available replacement for most existing cast iron steam boilers is almost impossible. The few manufacturers that still make these boilers are not providing definite lead times or shipping dates for orders. One large manufacturer has stopped taking orders. The future supply is questionable.

If you have a commercial steam boiler, we recommend having it accessed and planning for the future.


The biggest factor that differentiates a steam boiler is the amount of energy it uses to convert water at its boiling point into steam and raise the temperature of the steam above the boiling point. This super-heated steam is then distributed to the radiation, which releases heat to the heated spaces and converts the steam back to water before returning it to the boiler to start the process all over again. A commercial heating boiler does not actually boil water except when it’s a steam boiler. A steam boiler must burn more fuel to raise the temperature of the water to a boiling level and convert it to super-heated steam. Converting water into steam in the boiler efficiently and then converting it back to water by removing heat efficiently in the steam radiation is vital to conserve energy dollars and increase the life of all system components. It’s not enough just to heat the water. It must be converted to steam. Failure to raise a head of steam will result in no heat at all.

Most Common Problems with Steam Boiler Systems:

  1. No heat
  2. Not enough heat
    • Problems with burner input
    • Water surging resulting in burner short cycling
    • Failure of steam traps
  3. The water level is frequently low
    • Failing water level controls
    • Improper condensate return causes fresh water to be introduced
  4. Pipes are noisy
    • Water accumulation in piping coming in contact with steam
  5. Radiator and piping leaks
    • Loss of steam and hot condensate is a loss of energy dollars
    • Fresh water is brought into the system to make up for these leaks causes acidity in the system and will result in a rapid deterioration of all system components
  6. The radiator won’t heat
    • Steam supply, steam trap, or air vent problems

A water meter that is monitored for consumption is a must on all steam boiler systems.

The proper operation of steam traps is also crucial to efficient system operation. Most manufacturers recommend a check of steam trap operation annually and replacement in as little as three years.

Low water safety controls, pressure controls, and pressure relief valves must be serviced regularly to ensure safe operation and prevent the possibility of dangerous situations which can include a boiler explosion.

Let the team at Ambrose Mechanical Services, repair and maintain your steam boiler system.

Call us today for a system assessment: 585-663-7826


A: Steam boilers are controlled by pressure and will have pressure gauges and pressure controls. They also are not full of water like a water boiler, so they have a gauge glass that shows the water level in the boiler. See our video on how to identify a steam boiler

A: It depends on the type of steam boiler and the usage. At a minimum a Commercial steam boiler should be blown down (flushed) at least once a week to keep your steam boiler repair to a minimum

A: Steam boiler maintenance is best performed by a heating professional. Flushing or what is commonly called blow down is performed by draining a small amount of water at the drains located at the base of the boiler, water gauge glass and low water safety controls. Steam boiler annual maintenance should include completely draining and refilling.

A: Too much water will prevent the water from turning to steam and will create a banging noise in the piping.

A: A commercial steam boiler heats water and converts it to steam. Commercial steam boiler owners sometimes request steam heater repairs. Several parts of a steam system could be considered a steam heater. The boiler generates the steam which is sent to other equipment such as radiators and fan coil units to distribute the heat.

A: Steam boilers are not controlled by temperature. They are controlled by pressure limiting controls. It is essential that steam boiler annual maintenance include a check of all operating and safety controls. Commercial steam boiler maintenance should include a check of these controls at least twice per season and industrial boiler maintenance may be as often as once per week. Space temperatures are usually controlled by thermostats in each area which control the output of the heat emitters in the area.

A: The banging noise is caused by steam meeting water in piping or radiators. Some of the reasons for this are steam traps not working properly, improperly pitched piping and flooding of the boiler.

A: NO. One of the most harming things for a steam system is the addition of fresh water to make up for leaks. The oxygen is the fresh water will create acidity in the heating system which will destroy valves, traps, piping, and the boiler itself, sometimes in a short period. Leaks should always be corrected as soon as possible. For all commercial steam boilers, we recommend installing a water meter on the water supply line and monitoring it on a regular basis. This simple step can save a lot of trouble and expense.

A: Contact us today for additional guidance on how to maintain your steam boiler.

How to identify a commercial steam boiler from a water boiler: