Every year, the boiler for a steam or hydronic heating system sits unused for months. Any wear and tear from the previous winter can go unnoticed and can cause the boiler to be inefficient or ineffective once the heat is switched on again. Just as with a car or any other mechanical device, it is important to give a boiler a periodic tune-up, especially when it has not fired since the previous heating season. A boiler tune-up involves a number of steps that ensure that the boiler will run at peak efficiency. First, the combustion efficiency must be measured using an electronic flue gas analyzer. Such a test measures the “health” of a boiler, revealing the stack temperature, efficiency at which fuel is converted to heat, and levels of potentially harmful exhaust gases. Analysis of these numbers can indicate what types of improvements should be done on the boiler, or if it should be replaced entirely. Next, a few adjustments can be made to the boiler itself, including inspecting and cleaning the burner nozzles, changing the burner input or draft control as necessary, and cleaning the combustion chamber and fire-side exchange surface. These processes remove soot and other damage left over from months of repeated firing, while making sure that all boiler settings are at appropriate levels. The distribution system must also be examined during a tune-up. After checking the boiler itself, a heating professional will look for proper venting and complete a visual inspection of piping and insulation. Finally, the safety of the boiler will be checked by examining the safety controls and making sure there is adequate air for combustion, guarding against the dangerous gaseous byproducts of incomplete combustion.