Despite the name, an expansion tank isn’t a device you purchase when you want to add more water to your home boiler. (Unless you’ve lost water from a leak, you don’t want to add additional water to your boiler anyway.) You already have an expansion tank on your boiler: it’s one of the most crucial parts of your boiler’s regular operation.
Expansion tanks are an important part of any closed water heating system in use today. They serve the function of preventing a buildup of excessive pressure within the tank, mostly through using air to cushion the extra pressure. Without an expansion tank, your boiler would be less safe and more prone to leaks and breakdowns from mounting pressure. However, the sturdiest boiler ever constructed with an effective expansion tank can still require repairs. You will eventually have to call professionals to work on your boiler in Ham Lake, MN.
Air Mechanical Inc is available 24 hours a day to give you the service you need.
Here are a few things you should know about the operation of an expansion tank:
Older boilers were not built as well-sealed as current ones, so they had excess air within the tank itself that served to reduce the air pressure, although it was a crude system. The current model of expansion tank sits above the boiler tank, with a pipe running from the boiler into one side of the unit. The inside consists of two sections with a rubber diaphragm between them. The side connected to the tank is filled with water that comes in from the pipes. The other side contains pressurized air with a valve to check the pressure and add air to keep it balanced. If the pressure of the water increases, the water pushes against the diaphragm and compresses the air on the opposite side, and this relieves the pressure inside the boiler. When the water pressure drops, the diaphragm pushes back against the water as the valve regulates the air pressure to normal.
Older expansion tanks did not use a diaphragm, and instead had the water pressing directly against a pressurized air pocket. However, this allowed the introduction of too much oxygen into the water, which increased corrosion.
Trouble with an expansion tank, such as a rupture in the diaphragm or leaks in the air valve, can cause the boiler to overheat from increased pressure. Expansion tanks can be repaired or replaced if they malfunction, but because this is such a critical part of your boiler’s operation, you should only trust this job to professionals. Air Mechanical Inc has a quarter of a century of experience working with boilers, so if you have difficulties with the expansion tank on your boiler in Ham Lake, MN—or any kind of home heating trouble—we are one of your best resources.