Steam boilers are the heart of many efficient home and apartment heating systems. Because they have few moving parts, there is little to go wrong with them. Hopefully, you'll spend more time enjoying them than fixing them. The first step is understanding how they work so you can easily maintain them. Also see the Hot-Water Boiler Fix-It Guide .

How Does It Work?

Components of a typical steam boiler.

A steam heating system consists of a boiler to heat steam, a network of pipes that distribute the steam, and radiators that heat various rooms. A gas or oil burner heats water to the boiling point and sends hot steam to radiators in the residence. Modern boilers circulate water around the heat source through a series of passages or tubes. Boiler operation is regulated by a pressure gauge, regulator, pressure-relief valve, and low-water cutoff monitor. Most steam boilers include an automatic feed that supplies more water when it's needed.

What Can Go Wrong?

Regular maintenance will help keep repairs to a minimum. The system may produce no heat or poor heat, water may be chronically low, the glass gauge may be clouded, and pipes may be noisy.

Fix-It Tip

For safety and efficiency, make sure that there is a clear path around each radiator to allow air to circulate freely.