How to Troubleshoot a Gas Steam Boiler Heating System

Short Cycling

• 1

  Look around your home to make sure all of the vents or registers are open. If they are shut or blocked, your boiler may overheat, causing it to shut down frequently.

• 2

  Clean the filters. Filters can get clogged over time and make it difficult for the boiler to push hot air through the system. Like blocked vents, this can cause short cycling due to overheating. Filters should be cleaned -- or replaced in the case of disposable filters -- every three months. The filter location varies by model, but it is usually inside the blower compartment.

• 3

  Check the thermostat. Make sure the setpoint is high enough that the boiler needs to stay on and ensure that the thermostat is not located in a place where a draft from your heating system is affecting its regulation.

• 4

  Inspect the limit switch on the boiler itself and adjust the settings if necessary. This control shuts down the boiler when it gets too hot, and the higher it is set, the longer the furnace should run before it shuts down. On most models, the limit should not be set above 200 degrees, or else there is a risk of overheating.

No Heat

• 5

  Start with your thermostat. Make sure it has fresh batteries, is turned on and is set to "heat." The setpoint must be above the current room temperature in order for the boiler to turn on.

• 6

  Check the safety switch or reset button on the boiler to see if it has tripped. If it has, press the reset button to start the boiler. If it has not been tripped or if resetting it does not solve the problem, proceed to the next step. Do not repeatedly press the button as this can overload the combustion chamber with fuel.

• 7

  Verify the electrical power by making sure that all switches on the boiler that need to be turned on are on. Check the circuit breakers and fuses. Replace any blown fuses or reset tripped breakers if necessary.

• 8

  Make sure there is fuel in the gas tank. The tank should have a gauge that you can refer to for assessing the fuel level; if the marker is lower than 10 percent, you are out of fuel.

Boiler Noise

• 9

  Check all of the valves to and from the boiler and reset them to their proper levels, according to your boiler's manual. Popping and bubbling noises are often caused by insufficient water levels.

• 10

  Make sure the radiator is sloped the right way. The entering steam pipe should be slightly higher than the other end to prevent noisy condensation problems. You can use shims to change the slope of the radiator.

• 11

  Call a certified technician to test the pH of your boiler water, inspect it for mineral deposits and de-lime the boiler if necessary.